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Topic: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: moderators
Posted 2010-12-05 07:32:29 and read 25159 times.

Dear members,

This is a continuation thread from part 2 which can be found here: 787 Test Flight Evacuated Due To Smoke - Part 2


Please feel free to add your comments to the thread. Enjoy the website!


Rgds

The Forum Moderators

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Stitch
Posted 2010-12-05 07:50:40 and read 25150 times.

As much as Boeing has c**ked-up on the 787 program and even if it is taking the electrical system of a commercial airliner to new levels, Boeing and their suppliers (like Hamilton-Sunstrand) have been designing aircraft electrical systems for a very long time.

I really cannot believe that they designed a system with a single-point of failure in it.

The system may very well not have responded as designed and will need to be modified so that it does, but to those who claim Boeing will need years to completely re-design the architecture seem to be putting their own biases against Boeing ahead of common sense.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Revelation
Posted 2010-12-05 07:52:05 and read 25122 times.

Quoting JoeCanuck (Reply 242):
A design change to the P cabinets is still a design change and not a wholesale change to the aircraft.

Not sure what point is being made here, but it appears the change will also impact software, which may or may not reside in the P cabinets.

Quoting packsonflight (Reply 248):
Is Boeing somewhere on record saying directly there was a foreign object?

Oh no, not this again.

Quoting Revelation (Reply 237):
Oh no, not this again.

As from before:

Quoting Revelation (Reply 171):
Seattle Times reports:

Quote:

Boeing doesn't know what the foreign object was, because whatever it was burned up in the fire, spokeswoman Lori Gunter said.

"It was small, it wasn't as big as a tool," she said. "A tool would leave evidence."

And earlier they say:

Quote:

Engineers have determined that the fault began as either a short circuit or an electrical arc in the P100 power-distribution panel, most likely caused by the presence of foreign debris, the company said

So, Boeing isn't even 100% sure it was FOD, and they certainly have not located any FOD that they can link to the event.
Quoting Rheinbote (Reply 250):
Interesting to see how the Boeing communications department succeeded in turning the discussion towards what the "most likely" root cause for the fire might have been, and whether this has to be labelled as FOD or...FOD.

I don't see how it's some amazingly effective effort from Boeing that's doing it, it just seems to be the thing people here on a.net and elsewhere want to talk about.

What was amazing is how they got all the photos yanked off the Internet, claming some sort of intellectual property rights. Well, at some point in the near future (hopefully!) the 787 will be out in the real world, and there won't be any problem for some mechanic to take all the photos they want to take. So to me it's clearly about damage control, not about intellectual property rights, and IMHO the press is being pretty cowardly in yanking the photos off the net.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-05 09:13:56 and read 24942 times.

From the prior thread: "The real story is not the fire. It is abot a single component failiure which lead to total power loss of L and R primary flight instuments."

I agree the real story is the system response, but can we please stop speculating that there was total loss of power to the L & R primary flight instruments without some evidence? If you lose power for the L & R primary flight instruments then you've lost power for *all* the primarily flight instruments, which I haven't seen in any report anywhere. I've seen lots of reports that some, but not all, flight deck displays were lost. If some of the displays were working, then they didn't have total power loss.

A lot of people appear to be hanging this supposition on the fact that the RAT dropped. One of the RAT drop conditions is total loss of L & R instrument power, but it's not the only one. I also owe Zeke (and everyone else paying attention to that part of the thread) some research on that.

However...*given* that we're all pretty sure the electrical system didn't respond properly to the fault, I'm pretty leary of then pinning all our hopes of diagnosing the power state on the RAT performing exactly as designed. If we know the power system did something weird, it seems strange to limit the weirdness to one area while assuming that another worked 100% as expected (especially since it would be responding to an unexpected configuration change).

Quoting Stitch (Reply 1):
I really cannot believe that they designed a system with a single-point of failure in it.

I can't either, which is why I got so into the "one bus" versus "four bus" and "architecture" vs. "component" distinction. A single bus with a single-point failure is so obviously stupid (and obviously uncertifiable on its face) that it basically can't be the way the plane is built.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dynamicsguy
Posted 2010-12-05 09:41:41 and read 24874 times.

Quoting slz396:
You are of course free to stick to your personal and very limited definition of what architecture is only about

Since you're so keen on ignoring the context and making up your own meaning for what is a technical term, here's one of several dictionary meanings of "architecture":

Quote:
the arrangement of the various devices in a complete computer system or network

Wikipedia provides a decent definition here

In the context of structures we use architecture to describe the basic layout, for example the layout of skins, spars, ribs and fittings in a flap.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-05 11:31:49 and read 24685 times.

Quoting dynamicsguy (Reply 4):
ght deck displays were lost. If some of the displays were working, then they didn't have total power loss.


"Some displays where working" could mean that Standby Instruments where working, and on the Boeings I have flown they are powered from battery for 30 minutes.
If it comes down to that and electrical power can not be restored in this 30 minutes, your standby instruments will blank as well and that is not good.

Looks like Zeke has the 787FCOM, It would be nice if you could post here QRH checklist for "LOSS OF ALL AC BUSSES" or "DUAL ENGINE FAIL" specially the part of the dual engine failiure checklist that comes after" APU NOT AVAILABLE"
Normally there is a reading there which describes the condition the aircraft is in.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Rheinbote
Posted 2010-12-05 11:56:42 and read 24604 times.

The question is whether P200 stayed online when P100 failed or not.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-05 12:11:13 and read 24578 times.

Quoting packsonflight (Reply 5):
It would be nice if you could post here QRH checklist for "LOSS OF ALL AC BUSSES" or "DUAL ENGINE FAIL" specially the part of the dual engine failiure checklist that comes after" APU NOT AVAILABLE"

Interestingly enough, those electrical checklists aren't published yet!  Wow!

But given how the 787 has reacted to the shortcircuit due to the fire, they'd have to be very short then!

If Boeing wants to offer flight crews a solid procedure for all cases where they don't have the luck to be on final approach already, they will have to come up with "a set of meaningful upgrades and modifications to the design of several soft- and hardware components", never to be called an "architectural redesign" of course.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dynamicsguy
Posted 2010-12-05 12:21:02 and read 24543 times.

Quoting slz396 (Reply 7):
they don't have the luck to be on final approach already

This is about the only thing about this failure which Boeing has been unequivocal on. It has been explicitly stated that they could have returned from any point on a typical mission.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 12:24:00 and read 24540 times.

Quoting slz396 (Reply 7):

If Boeing wants to offer flight crews a solid procedure for all cases where they don't have the luck to be on final approach already,

I'm curious, what luck was involved? Boeing has said that at no point, was flight control or primary flight instrumentation lost after the fire and that the plane could have landed safely at any point in a typical flight profile.

Now, I agree it is possible that Boeing is lying but there was at least one FAA pilot in the cockpit, and the FAA is undoubtedly intimately involved in any analysis and fix. So far, the FAA has not publicly contradicted anything Boeing has said.

So, for Boeing to be lying, then the FAA must be lying on behalf of Boeing.

If the FAA is lying, it would be a very serious breach of their mandate, and possibly criminal. If you have any information to this effect, I think there are authorities who would be very interested in this information...as would we.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-05 12:47:07 and read 24452 times.

Quoting JoeCanuck (Reply 9):
what luck was involved?


You don't think you're lucky to be stabilized on short final with the RWY in sight when you have an onboard fire then???

Quoting dynamicsguy (Reply 8):
This is about the only thing about this failure which Boeing has been unequivocal on. It has been explicitly stated that they could have returned from any point on a typical mission.

Boeing is indeed saying the crew could have flown the plane to safety from any point on a typical mission profile, but they fail to say what procedure should have to be applied then and whether they assume a correct isolation of the faulty busses first?

Boeing are very good at choosing their words extremely carefully so as to sound very convincing, while guaranteeing nothing at all really, unless certain preconditions are assumed to be met, preconditions which were purely event specific, rather than the result of procedural crew actions... I guess that's just a detail, right?

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 13:03:32 and read 24399 times.

Quoting slz396 (Reply 10):

You don't think you're lucky to be stabilized on short final with the RWY in sight when you have an onboard fire then???

The safe landing was because of the skill of the pilots and the reliability of the aircraft. If either one was lacking, then luck would have been needed.

At no point was control lost and at all times the pilots had the flight instrumentation required to land the plane. Luck wasn't necessary.

Quoting slz396 (Reply 10):

Boeing is indeed saying the crew could have flown the plane to safety from any point on a typical mission profile, but they fail to say what procedure should have to be applied then and whether they assume a correct isolation of the faulty busses first?

Boeing are very good at choosing their words extremely carefully so as to sound very convincing, while guaranteeing nothing at all really, unless certain preconditions are assumed to be met, preconditions which were purely event specific, rather than the result of procedural crew actions... I guess that's just a detail, right?

Why would Boeing have to tell us what procedures are required for anything? They only have to convince the FAA, not speculators on forums. So far, the FAA has not contradicted anything Boeing has said, nor have they felt the need to clarify or amend anything.

There are always preconditions for every procedure. For example, one of the preconditions for a normal landing procedure is that the gear is down and locked. Is Boeing required to tell the posting public exactly what sequence of events has to take place in order to do that?

No airline manufacturer has to tell the public anything about their procedures. Airbus didn't have to tell the public their exact procedures for a #3 LP disc ejection creating massive holes in the fuel tanks, disabling or damaging 2 hydraulic systems and limiting the use of some flight controls...and I don't expect them to.

I expect Airbus to make a plane robust enough to take unexpected damage and still land safely even though the crew wasn't specifically trained for that event...which they did. I expect the same from Boeing.

Exactly what is required would be interesting but really isn't my business.

[Edited 2010-12-05 13:18:45]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Stitch
Posted 2010-12-05 13:52:30 and read 24282 times.

Quoting JoeCanuck (Reply 9):
Now, I agree it is possible that Boeing is lying but there was at least one FAA pilot in the cockpit, and the FAA is undoubtedly intimately involved in any analysis and fix. So far, the FAA has not publicly contradicted anything Boeing has said.

Hell, the FAA guy was flying the plane, I believe.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-05 14:04:23 and read 24237 times.

Quoting Stitch (Reply 12):
No airline manufacturer has to tell the public anything about their procedures. Airbus didn't have to tell the public their exact procedures for a #3 LP disc ejection creating massive holes in the fuel tanks, disabling or damaging 2 hydraulic systems and limiting the use of some flight controls...and I don't expect them to.


Boeing dont want the public to realize that if this failiure (Power loss on L&R primary flight display) happened over the middle of the Atlantic, the airplaine would not make it to shore if it would enter single cloud on the way.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 14:36:45 and read 24160 times.

Quoting packsonflight (Reply 13):

That was actually me you quoted.

Boeing did say it and the FAA haven't contradicted it. Unless the FAA is essentially lying for Boeing, they must believe it too.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-05 15:38:24 and read 24014 times.

Quoting slz396 (Reply 7):
Interestingly enough, those electrical checklists aren't published yet!

Of course they're not...it's not a certified aircraft. The final manuals are about the last thing you complete during a new type certification program, since they rely most on the integration of all prior flight test data.

Quoting slz396 (Reply 10):
You don't think you're lucky to be stabilized on short final with the RWY in sight when you have an onboard fire then???

An onboard fire that self-extinguishes, doesn't threaten the pilots' ability to fly or operate the airplane, and leaves the plane in a configuration suitable for a 6+ hour diversion? Yes, I don't think that was luck.

Quoting packsonflight (Reply 13):
Boeing dont want the public to realize that if this failiure (Power loss on L&R primary flight display) happened over the middle of the Atlantic, the airplaine would not make it to shore if it would enter single cloud on the way.

1) So far, there's no evidence that L&R primary flight displays all went down.
2) How would entering a cloud make any difference? Even if all the PFD's were down, the ISFD displays all the same information (just on a smaller format).

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Bennett123
Posted 2010-12-05 15:53:26 and read 23971 times.

So far, I have seen no confirmation of when flying will re commence.

Will the weather have a major impact on the timing of testing being resumed or the pace of it?.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: keesje
Posted 2010-12-05 15:55:54 and read 23970 times.

Quoting tdscanuck (Reply 15):
1) So far, there's no evidence that L&R primary flight displays all went down

It did not follow the previosu long thread. But I had the impression 1 display on the left side remained functional and that was the reson the FAA pilot did the landing (he was in the left seat)

During the failure of the P100 power panel, which was first noticed as ZA002 crossed through 1000ft above ground level (AGL), multiple engine indication and crew alerting system (EICAS) messages appeared on flight deck displays before load shedding reduced the available displays to a single screen on the left side of the flight deck.
A source with direct knowledge of the incident says both heads up displays (HUD) were disabled as well and another says the location of the sole active display ultimately determined which member of the flight crew landed the aircraft.


http://www.flightglobal.com/articles...a-at-controls-during-787-fire.html

If this report has been denied or proved wrong I missed it too.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kaiarahi
Posted 2010-12-05 15:56:18 and read 23965 times.

Quoting slz396 (Reply 7):
never to be called an "architectural redesign" of course.

Still flogging the same horse? From the last thread:

"Tom's use of the word "architecture" is exactly how it is understood when referring to electrical / IT systems. Nothing to do with bricks and mortar. You could start by checking out the definition of "system architecture" or "systems architect".


Dakota wisdom, passed on from generation to generation, says:

"When you discover that you are riding a dead horse, the best strategy is to dismount and get a different horse."

However, in some organizations, more advanced strategies are employed:

1. Buying a stronger whip.
2. Changing riders.
3. Appointing a committee to study the horse.
4. Rewriting the performance requirements for all horses.
5. Visiting other countries to see how different cultures ride dead horses.
6. Lowering standards to include dead horses.
7. Reclassifying the dead horse as “living impaired”.
8. Hiring outside contractors to ride the dead horse.
9. Harnessing several dead horses together to increase speed.
10. Providing additional funding or training to increase the dead horse's performance.
11. Doing a productivity study to see if lighter riders would improve the dead horse's performance.
12. Promoting the dead horse to a supervisory position.
13. Declaring that since the dead horse does not have to be fed, it is less costly, carries lower overhead and therefore contributes substantially more to the bottom line of the economy than do some other horses.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-05 17:52:51 and read 23829 times.

Quoting Stitch (Reply 1):
The system may very well not have responded as designed and will need to be modified so that it does, but to those who claim Boeing will need years to completely re-design the architecture seem to be putting their own biases against Boeing ahead of common sense.

I don't know about that, I can easily see a years delay; when you start mucking with electrical designs, hardware and logic in critical systems it is never quick every step will have to be signed off tested documented, tested, fabricated, tested, QA'd installed, tested signed off, (maybe gauntled?) before it is ever released for flight testing. Simple huh, now add all the subcontractors and their subcontractors and the FAA and the three separate resolution strands.

Then they have the nagging condensation problem, if its bad with 52 persons on board what will happen with 300? And the rest of the flight test program (Ok, and though I hate to mention it we also have slight RR doubts)

There was at least 3 months (from November till the mid feb last official 1st delivery date) worth of flight testing to complete and thats not including new tests that may be required for the new design architecture plus re-running tests that were completed under the old architecture.... A year is easily possible, could be 6 months, its going to be longer that 3 months but seeing a year delay IS possible without being a Boeing hater.

Quoting tdscanuck (Reply 3):
However...*given* that we're all pretty sure the electrical system didn't respond properly to the fault, I'm pretty leary of then pinning all our hopes of diagnosing the power state on the RAT performing exactly as designed. If we know the power system did something weird, it seems strange to limit the weirdness to one area while assuming that another worked 100% as expected (especially since it would be responding to an unexpected configuration change).

You make a good point

Quoting tdscanuck (Reply 3):
I can't either, which is why I got so into the "one bus" versus "four bus" and "architecture" vs. "component" distinction. A single bus with a single-point failure is so obviously stupid (and obviously uncertifiable on its face) that it basically can't be the way the plane is built.

But the problem here is if the architecture is hidden from the guys doing the troubleshooting (Pilots) then they do not have the necessary information to make informed decisions, further I would contend that this shows the limits of auto configuration, smart system failover is good but if that auto failover fails where does that leave the guys at the pointy end? In the end the system has to be transparent enough to fix or at least be able to pin down what has failed. You and Zeke are both correct, from your respective program perspectives but don't you see the dangers in the manuals leading pilots to misunderstand whats underneath them?

As a systems guy I can see why someone would design a critical system like this, to "keep the users out" but this approach has its limits, as automation adds complexity, the more complex a system the more prone it is to entropic failure.

Quoting dynamicsguy (Reply 8):
This is about the only thing about this failure which Boeing has been unequivocal on. It has been explicitly stated that they could have returned from any point on a typical mission.

Which is a long way short of saying that it could have completed a mission at max ETOPS range that they are proposing certification for.

Quoting JoeCanuck (Reply 9):
I'm curious, what luck was involved? Boeing has said that at no point, was flight control or primary flight instrumentation lost after the fire and that the plane could have landed safely at any point in a typical flight profile.

Which is a long way short of saying that it could have completed a mission at max ETOPS range that they are proposing certification for.

Quoting JoeCanuck (Reply 9):
If the FAA is lying, it would be a very serious breach of their mandate, and possibly criminal. If you have any information to this effect, I think there are authorities who would be very interested in this information...as would we.

The FAA is silent, silence is not necessarily a sign that they agree with Boeings statements on the 787

Quoting JoeCanuck (Reply 11):
Why would Boeing have to tell us what procedures are required for anything? They only have to convince the FAA, not speculators on forums. So far, the FAA has not contradicted anything Boeing has said, nor have they felt the need to clarify or amend anything.

They do have to convince pilots though and several of them on this forum seem to be unconvinced, they also need to convince the JAA and other certification authorities

[Edited 2010-12-05 17:54:09]

[Edited 2010-12-05 18:08:39]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: 14ccKemiskt
Posted 2010-12-05 18:08:38 and read 23796 times.

Seems like it has been raining in in the plane during tests flights.

http://www.tradingmarkets.com/news/s...bedeviling-for-boeing-1347952.html

//14cc

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: XT6Wagon
Posted 2010-12-05 18:13:14 and read 23787 times.

Quoting slz396 (Reply 7):
If Boeing wants to offer flight crews a solid procedure for all cases where they don't have the luck to be on final approach

You think final approch is the best place to have problems? Whoh. While the pilots are going to be more on the ball than say cruise... Final approch is a horrible place to have problems. Low airspeed, low altitude, low thrust, high drag? Only place worse IMO is something critical happening right at V1 on a runway with no excess room.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: wolbo
Posted 2010-12-05 18:25:03 and read 23756 times.

Quoting 14ccKemiskt (Reply 20):
Seems like it has been raining in in the plane during tests flights.

http://www.tradingmarkets.com/news/s...bedeviling-for-boeing-1347952.html

Maybe that's why the fire self-extinguished?   

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Stitch
Posted 2010-12-05 18:28:37 and read 23747 times.

Quoting 14ccKemiskt (Reply 20):
Seems like it has been raining in in the plane during tests flights.

It sounds like something endemic to CFRP fuselages as Airbus had noted they too have been working on condensation problems with A350XWB test barrels (I am guessing during environmental tests on them?).

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-05 18:28:43 and read 23743 times.

Quoting Bennett123 (Reply 16):
Will the weather have a major impact on the timing of testing being resumed or the pace of it?.

Depends on the weather...they're moving into exactly the same weather window that was around first flight, and that seemed to be reasonably productive. However, this winter is supposed to be more severe than last in the Pacific NW. As long as you can get off the ground though, flight testing isn't usually stopped by weather, just slowed down. You can always fly to the weather you need, especially with an airplane with that much range.

Quoting keesje (Reply 17):
It did not follow the previosu long thread. But I had the impression 1 display on the left side remained functional and that was the reson the FAA pilot did the landing (he was in the left seat)

That was my impression too, which is why I don't understand where the repeated claims that all displays failed is coming from.

Quoting BoeingVista (Reply 19):
I don't know about that, I can easily see a years delay; when you start mucking with electrical designs, hardware and logic in critical systems it is never quick every step will have to be signed off tested documented, tested, fabricated, tested, QA'd installed, tested signed off, (maybe gauntled?) before it is ever released for flight testing.

Although I agree it's not a trivial thing, I still don't see how it causes an full year delay. To make what Boeing is calling "hardware upgrades" and some software changes can't take a year. The side-of-body problem, which was a lot more fundamental, only took 6 months to go through the entire document/test/fab/test/QA cycle. If it really does take a year, Boeing is lowballing the scope of the problem in all their current releases (and a *lot*, not use usual PR fudging).

Quoting BoeingVista (Reply 19):
Then they have the nagging condensation problem, if its bad with 52 persons on board what will happen with 300

I would assume they used a lot more than 52 people, or at least 52 equivalent people. You can do a lot with heater blankets and humidifiers to simulate people, and it's safer than using a planeload.

Quoting BoeingVista (Reply 19):
A year is easily possible, could be 6 months, its going to be longer that 3 months but seeing a year delay IS possible without being a Boeing hater.

I agree it's possible, I just don't think it's probable based on what's been released so far. Obviously, if it's worse than the current evidence suggests, the delay could be longer.

Quoting BoeingVista (Reply 19):
But the problem here is if the architecture is hidden from the guys doing the troubleshooting (Pilots) then they do not have the necessary information to make informed decisions

Pilots aren't generally supposed to troubleshoot. They're supposed to follow the procedures (which may include troubleshooting, but it's structured and planned). About 30 years ago, aircraft passed the point where the true architecture of all systems can be made plane to the flight crew without suffering a huge information overload problem. The whole principle of modern flight deck design is to present the pilots with the information they need to safely operate the aircraft and no more.

Quoting BoeingVista (Reply 19):
further I would contend that this shows the limits of auto configuration, smart system failover is good but if that auto failover fails where does that leave the guys at the pointy end?

With a flyable airplane that could land safely. Why or how you lost power isn't nearly as important as maintaining continued safe flight and landing, which worked just fine in this case.

Quoting BoeingVista (Reply 19):
You and Zeke are both correct, from your respective program perspectives but don't you see the dangers in the manuals leading pilots to misunderstand whats underneath them?

I do see the danger, although I disagree that the manuals are misleading. Once I read more of the FCOM, thanks to Zeke's prompting, I found the part where it very clearly states what the actual bus architecture is.

Quoting BoeingVista (Reply 19):
Quoting dynamicsguy (Reply 8):
This is about the only thing about this failure which Boeing has been unequivocal on. It has been explicitly stated that they could have returned from any point on a typical mission.

Which is a long way short of saying that it could have completed a mission at max ETOPS range that they are proposing certification for.

Not really. A "typical mission" for a 787 is an ETOPS route. Not max-ETOPS, which you only find on a tiny percentage of routes, but it is an ETOPS route. And it's certainly more than 30 minutes, which is the battery time. So Boeing's statement means, at minimum, the airplane was left in a state where it was safely flyable and landable in a steady state configuration. And, unless there's some other time-dependant failure going on (the only one we know about, the fire, self-extinguished), then once you're steady-state you can keep going until you run out of fuel.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: wolbo
Posted 2010-12-05 18:36:31 and read 24035 times.

From the posted article this part seems relevant to our ongoing discussion:

Quote:
Analysts are troubled that the fire triggered an apparent software malfunction that also caused the 787's unaffected power systems to shut down. The plane's only source of power was a ram air turbine, a small, propeller-powered generator outside the plane whose output is sufficient to power only basic flight functions.

"The 787, like all aircraft, has a large number of redundancies built in," said Hans Weber, president of Tecop International Inc., an aviation consultancy. "A failure somewhere in the electrical system is not supposed to take the entire system down."

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 18:40:49 and read 24053 times.

Quoting BoeingVista (Reply 19):
Which is a long way short of saying that it could have completed a mission at max ETOPS range that they are proposing certification for.

If a typical flight profile includes ETOPS, then Boeing is indeed saying it could have completed a mission at max ETOPS range.

Quoting BoeingVista (Reply 19):

The FAA is silent, silence is not necessarily a sign that they agree with Boeings statements on the 787

Indeed. The FAA hasn't agreed with Boeing's statements but they haven't disagreed with them either. Since they are in a position to know, I don't know why they would keep silent if Boeing was blatantly lying.

Quoting BoeingVista (Reply 19):
They do have to convince pilots though and several of them on this forum seem to be unconvinced, they also need to convince the JAA and other certification authorities

There are lots of people and organisations they have to convince. I doubt their policy is to do it through message boards.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-05 19:21:54 and read 24374 times.

Quoting JoeCanuck (Reply 26):
Indeed. The FAA hasn't agreed with Boeing's statements but they haven't disagreed with them either. Since they are in a position to know, I don't know why they would keep silent if Boeing was blatantly lying.

I don't think they are blatantly lying just using PR tools and a bit of Astroturf for misdirection.

The FAA hasn't said that the 787 is grounded but the reality is it is! Boeing has not said that it is not grounded so there is no conflict between the 2 positions and no need for the FAA to speak. Boeing has said it has suspended the test program but in reality if they tried to continue the the test program FAA would prevent them from doing so.

No one has lied.

Quoting tdscanuck (Reply 24):
I agree it's possible, I just don't think it's probable based on what's been released so far. Obviously, if it's worse than the current evidence suggests, the delay could be longer.

A lot depends on if they can resume flying before the complete fix is implemented and how much of the original flight test program remains to be completed both of which are unknowns, but added to that we don't know how much of the original test program will have to be re-run on the new electrical system or if the failure has prompted the FAA to look more widely at the certification process.

Although obviously I have no first hand knowledge I would assume that most of the electrical system had already been certified to the FAA under the assumption that all fail modes were understood, this now turns out to be incorrect, what are the implications of this.

Quoting tdscanuck (Reply 24):
With a flyable airplane that could land safely. Why or how you lost power isn't nearly as important as maintaining continued safe flight and landing, which worked just fine in this case.

Agreed.

Quoting tdscanuck (Reply 24):
Pilots aren't generally supposed to troubleshoot. They're supposed to follow the procedures (which may include troubleshooting, but it's structured and planned). About 30 years ago, aircraft passed the point where the true architecture of all systems can be made plane to the flight crew without suffering a huge information overload problem. The whole principle of modern flight deck design is to present the pilots with the information they need to safely operate the aircraft and no more.

Well, yes, troubleshoot via QRH and EICAS messages but these things work best if you understand "the system" in case the procedures are a bit dumb, the one the springs to mind was the conflict in the A330 manual between fuel imbalance and fuel leak which stumped the Air Transat guys; fuel imbalance cross feed on, fuel leak cross feed off while they were working through this they dumped all their fuel through a broken pipe. You have to understand what you are operating so that you can sanity check the procedures.

Quoting JoeCanuck (Reply 26):
There are lots of people and organisations they have to convince. I doubt their policy is to do it through message boards.

Yeah, you're right that blows, do you think that as a community we can do anything about this?  Smile

[Edited 2010-12-05 19:23:19]

[Edited 2010-12-05 19:25:32]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 20:31:02 and read 23910 times.

Quoting BoeingVista (Reply 27):
The FAA hasn't said that the 787 is grounded but the reality is it is!

I thought the FAA did ground the fleet.

Quoting BoeingVista (Reply 27):
Yeah, you're right that blows, do you think that as a community we can do anything about this?

We could go on strike...that'd learn 'em...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-05 20:35:58 and read 23937 times.

Quoting Stitch (Reply 23):
It sounds like something endemic to CFRP fuselages as Airbus had noted they too have been working on condensation problems with A350XWB test barrels

Rain-in-the-plane is endemic to all pressurized airliners. Estimates vary, but most aircraft are packing several hundred pounds of water in their insulation, and another couple of hundred pounds of felt just to keep the condensation from actually getting onto the passengers. Douglas aircraft are notorious for rain-in-the-plane and still do it on a regular basis in service.

Quoting wolbo (Reply 25):
From the posted article this part seems relevant to our ongoing discussion:

Interesting article, and I agree with the spirit, but they're repeating the oft heard, totally false, mantra that the two panels (P100 and P200) are the entire power system.

Quoting wolbo (Reply 25):
The plane's only source of power was a ram air turbine, a small, propeller-powered generator outside the plane whose output is sufficient to power only basic flight functions.

*And* the battery, *and* the permanent magnet generators, *and* potentially the APU if they'd had enough time to start it before landing.

Quoting wolbo (Reply 25):
"A failure somewhere in the electrical system is not supposed to take the entire system down."

Agreed, and it didn't. It took down, apparently, the whole 235VAC system but, thanks to intelligent design on behalf of the engineers, the plane is obviously capable of safe flight and landing without that system. Now I think it's obvious that a failure in one panel shouldn't take down another, so there's work to be done, but this failure did not take down the entire power system. FBW airliners fall out of the sky if the *entire* power system fails.

Quoting JoeCanuck (Reply 26):
If a typical flight profile includes ETOPS, then Boeing is indeed saying it could have completed a mission at max ETOPS range.

Not exactly...a typical mission is ETOPS (it's very difficult to fly 8000 nm missions without doing ETOPS), but very very few routes are maximum duration ETOPS. 180-minute ETOPS covers something like 90%+ of all flying, even though the 787 appears that it might have all the way up to 330-minute ETOPS (reading between the lines of this article http://www.boeing.com/commercial/aer...ticles/qtr_2_07/article_02_4.html)

Quoting BoeingVista (Reply 27):
Although obviously I have no first hand knowledge I would assume that most of the electrical system had already been certified to the FAA under the assumption that all fail modes were understood, this now turns out to be incorrect, what are the implications of this.

Depends on exactly what was missed in the original pitch to the FAA, and what implication that has for other failure modes that have been missed. Best case, this was the one failure mode that wasn't properly handled, they show how the fix makes it work properly, and they go on about their way. Worst case, it exposes some flaw in the whole power system design and they have to start from scratch. However, given how far through the test program they got before they found this, I've got to assume the power system is pretty robust to all the other failures they've tried.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 20:57:44 and read 23761 times.

Quoting tdscanuck (Reply 29):

Rain-in-the-plane is endemic to all pressurized airliners.

Resistance to corrosion is one of the advertised advantages of CFRP. All that water collecting in the corners of a metal fuse has much more potential to cause problems than a composite one.

Quoting tdscanuck (Reply 29):

Quoting JoeCanuck (Reply 26):
If a typical flight profile includes ETOPS, then Boeing is indeed saying it could have completed a mission at max ETOPS range.

Not exactly...a typical mission is ETOPS (it's very difficult to fly 8000 nm missions without doing ETOPS), but very very few routes are maximum duration ETOPS. 180-minute ETOPS covers something like 90%+ of all flying, even though the 787 appears that it might have all the way up to 330-minute ETOPS (reading between the lines of this article http://www.boeing.com/commercial/aer...html)

I have no idea what Boeing considers a typical flight profile, (which is why I very carefully used 'if''). Whatever that is, they said the plane could have done it.

How much ETOPS testing has been conducted to this point?

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-05 22:11:33 and read 23343 times.

Quoting JoeCanuck (Reply 30):
How much ETOPS testing has been conducted to this point?

None, AFAIK the 787 has only gone TATL far as the UK and you don't need ETOPS for that

Quoting tdscanuck (Reply 29):
However, given how far through the test program they got before they found this, I've got to assume the power system is pretty robust to all the other failures they've tried.

Or you have a failure mode associated with wear a'la Trent 900 and it appears after 2000 or so hours. This could fall into the good or bad column.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: TheRedBaron
Posted 2010-12-05 22:18:04 and read 23326 times.

Quoting kaiarahi (Reply 18):
"When you discover that you are riding a dead horse, the best strategy is to dismount and get a different horse."

You made me laugh!

I try always to refrain from posting on the Saga of the Nightmareliner (yes I coined the slogan), but at this time is like the old "here comes the wolf" Tale. Boeing has had so many problems and a disastrous PR handling of the situation that any information no matter how accurate will be doubted.

I really hope they can fix the problems and get it to Service no later than second quarter of 2011... but after seeing how bad was the wiring fiasco of the A380, I would not bet on it.

I have always believed that the 787 program was like a politician who tries to get elected and promises WAY TO MUCH, they overpromised and so far have not delivered. As I have said before the parallel with the Dc8 program is striking.

REgards TRB

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-05 22:19:35 and read 23303 times.

Quoting BoeingVista (Reply 31):

Or you have a failure mode associated with wear a'la Trent 900 and it appears after 2000 or so hours. This could fall into the good or bad column.

It would seem to be both good and bad. It is possible to have a basically sound system made unreliable by one or two unsound pieces, or lines of code.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: TheRedBaron
Posted 2010-12-05 22:22:13 and read 23285 times.

ops I was not the first here:

Quote:
Looks more aircraft for me than the Boeing's nightmareliner.

-Joge
circa 2003

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dynamicsguy
Posted 2010-12-05 22:59:32 and read 23101 times.

Quoting BoeingVista (Reply 31):
None, AFAIK the 787 has only gone TATL far as the UK and you don't need ETOPS for that

That does not mean there has been no ETOPS testing. The airplane doesn't know when it is further than a certain distance from a suitable airport, so there's no need to fly routes which require ETOPS to test for ETOPS. Having said that, I don't know one way or the other whether there has been any.

[Edited 2010-12-05 23:02:53]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-05 23:14:01 and read 23044 times.

Quoting kaiarahi (Reply 18):
"When you discover that you are riding a dead horse, the best strategy is to dismount and get a different horse."

However, in some organizations, more advanced strategies are employed:

1. Buying a stronger whip.
2. Changing riders.
3. Appointing a committee to study the horse.
4. Rewriting the performance requirements for all horses.
5. Visiting other countries to see how different cultures ride dead horses.
6. Lowering standards to include dead horses.
7. Reclassifying the dead horse as “living impaired”.
8. Hiring outside contractors to ride the dead horse.
9. Harnessing several dead horses together to increase speed.
10. Providing additional funding or training to increase the dead horse's performance.
11. Doing a productivity study to see if lighter riders would improve the dead horse's performance.
12. Promoting the dead horse to a supervisory position.
13. Declaring that since the dead horse does not have to be fed, it is less costly, carries lower overhead and therefore contributes substantially more to the bottom line of the economy than do some other horses.

14. Asserting that the dead horse was still capable of fulfilling a typical mission profile

[Edited 2010-12-05 23:22:54]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-06 00:46:07 and read 22576 times.

Quoting Bennett123 (Reply 16):
1) So far, there's no evidence that L&R primary flight displays all went down.
2) How would entering a cloud make any difference? Even if all the PFD's were down, the ISFD displays all the same information (just on a smaller format).



There is a big difference between flight instruments and displays. Many screens in the 787 and instrument switching between them takes care of the problem if they fail, but as stated in 787FCOM one of the condition for automatic deployment of the RAT is loss of L&R flight instruments, and I think that is what happened.
The standby instruments are powered for 30 minutes only and after the battery depletes the standby horizon goes blank and without him it is not possible to fly through clouds.

This is all perfectly normal and according to FAR/JAR 25( the set of regulation commercial air crafts are certified to) and thus Boeing is saying that the system worked as designed. What is not normal is this single component failure resulting in total power loss, although I think the pilots could have restored power at least partially, but they opted to land as is. That is normal as well since they where on short final in a landing config.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-06 01:27:35 and read 22399 times.

Quoting BoeingVista (Reply 36):
14. Asserting that the dead horse was still capable of fulfilling a typical mission profile

ROTFL

Interestingly enough, Boeing has been using this method already in the past too, didn't they?
Still remember their hilarious comments when they had to admit to embarrassing structural deficiencies in the wing-to-body join?

It's a preventive measure only as the structure is most probably stong enough to fly using a "reduced envelope"  

That sounds awfully similar to their latest comments on the electrical issue, doesn't it?   

A typical mission profile could mean anything realy and definitely excludes certain missions the 787 should be capable of, just as a limited flight envelope does, all without saying what is included, and what isn't, thus leaving it to the appreciation of the reader to assume just how big the limitation actually is.
I'd like to hear them describe that typical mission profile of theirs unambiguously in relation to the problems experienced.
  

Does it include a Trans Atlantic night flight in winter, with snowstorms all across the continent of intended landing for instance? Sounds fairly typical too me!
Or are they just talking a typicial test mission in California, with tens of airports right below, all VFR?
Just what is a 'typical mission profile' and what is a 'reduced flight envelope'?

I've said it over and over again:
Boeing are constantly playing a game of words when talking about their 787, making statements which try to give the impression of maximum durability, while in fact they guarantee only mimimum conformity.
  

[Edited 2010-12-06 02:15:40]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kaiarahi
Posted 2010-12-06 04:58:10 and read 21277 times.

Quoting slz396 (Reply 38):
Boeing are constantly playing a game of words when talking about their 787, making statements which try to give the impression of maximum durability, while in fact they guarantee only mimimum conformity.

Just like Toyota, GM, Volkswagen, IBM, Dell, GE, Whirlpool, KitchenAid, Phillips, LG, Samsung, Caterpillar, Volvo, Ryobi, DeWalt .... It would be nice ti live in a world without PR, but I'm not holding my breath.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-06 05:16:30 and read 21126 times.

Quoting kaiarahi (Reply 39):
Just like Toyota, GM, Volkswagen, IBM, Dell, GE, Whirlpool, KitchenAid, Phillips, LG, Samsung, Caterpillar, Volvo, Ryobi, DeWalt

Sure, the only difference being that is if comes from Boeing, half of airliners.net takes it as coming straight from the bible and reads far more in it than they actually just said, flaming anybody that dares to question the exact carry of those words!

Statements containing delimiting yet non-defined pre-conditions like "okay to operate under a limited envelope" or now "could have landed from any point on a typical mission profile" are in fact completely meaningles and do nothing but timidly admit that indeed the plane can not be flown safely in all conditions where it should be, despite looking as saying the opposite!

Very sobering to see how many people simply ignore all of these limitating preconditions and simply assume them to be excluding only very remote cases at worst, something which is nowhere said by Boeing, all while accusing others of not wanting to read carefully what was said.

  

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-06 06:16:27 and read 20693 times.

Quoting JoeCanuck (Reply 30):
Resistance to corrosion is one of the advertised advantages of CFRP. All that water collecting in the corners of a metal fuse has much more potential to cause problems than a composite one.

Absolutely...huge maintenance benefit. But "rain-in-the-plane" usually specifically refers to the annoying habit of condensation dripping on the pax, as opposed to just having condensation somewhere in the fuselage.

Quoting JoeCanuck (Reply 30):
I have no idea what Boeing considers a typical flight profile, (which is why I very carefully used 'if'').

You can back it out from the specifications...it's about 250 pax with baggage for ~7000nm, thereabouts.

Quoting JoeCanuck (Reply 30):
How much ETOPS testing has been conducted to this point?

As others have posted, the plane can't tell how far it is from a diversion airport (from a systems point of view...the FMC obviously can). So it's really just "how much testing have they done where the plane flew for more than 6 hours." They're done plenty of that.

Quoting BoeingVista (Reply 31):
None, AFAIK the 787 has only gone TATL far as the UK and you don't need ETOPS for that

Absolutely true, but they've got lots of very long flights (beyond 14 hours, I think), which are just as stressful to the system as ETOPS flying is. What I haven't seen any news about is really long flights on a single engine.

Quoting BoeingVista (Reply 36):
14. Asserting that the dead horse was still capable of fulfilling a typical mission profile

So we're just assuming they're lying now?

Quoting packsonflight (Reply 37):
The standby instruments are powered for 30 minutes only and after the battery depletes the standby horizon goes blank and without him it is not possible to fly through clouds.

The *main* instruments are powered for 30 minutes by the ships battery. The standby instruments go for at least 30 minutes using their own internal battery. And, in either case, as soon as the RAT drops the critical instrument buses come back up and your time limit goes away. The batteries only need to carry you through until the RAT drops, not for the whole flight. Once the RAT drops, you've got primary flight display for as long as you're moving through the air.

Quoting packsonflight (Reply 37):
What is not normal is this single component failure resulting in total power loss

I agree that wouldn't be normal but, to repeat ad naseaum, they did *not* have total power loss. FBW airliners fall out of the sky with total power loss.

Quoting slz396 (Reply 38):
A typical mission profile could mean anything realy

No, it's well defined. Just because you don't know what the definition is doesn't mean it doesn't exist.

Quoting slz396 (Reply 38):
Does it include a Trans Atlantic night flight in winter, with snowstorms all across the continent of intended landing for instance? Sounds fairly typical too me!

Yes.

Quoting slz396 (Reply 38):
Or are they just talking a typicial test mission in California, with tens of airports right below, all VFR?
Just what is a 'typical mission profile' and what is a 'reduced flight envelope'?

No, it's not a test mission profile. Just how stupid do you think Boeing is? You can't design complex systems without defining the requirements *early* in the process, including the typical mission profile. This stuff was all nailed down years ago.

And, since you brought it up, "reduced flight envelope" also has a clear an unambiguous meaning. Just because you don't know what it means doesn't mean it's a meaningless statement. Based on all the public data I can find, Boeing was completely correctly that the planes could have flown under a reduced flight envelope without the side-of-body mod (reduced flight envelope means tightening up the Nz vs. GW curves).

Quoting slz396 (Reply 40):
Sure, the only difference being that is if comes from Boeing, half of airliners.net takes it as coming straight from the bible and reads far more in it than they actually just said, flaming anybody that dares to question the exact carry of those words!

I haven't seen anyone flamed for it; I have seen (and myself) criticized people for twisting Boeing's words into statements that aren't logically consistent with what Boeing said, which means that they're claiming Boeing is straight out lying. This is quite different than normal PR exaggeration, and quite easy to detect in hindsight so you very very rarely have companies flat out lie in a press release.

Quoting slz396 (Reply 40):
Statements containing delimiting yet non-defined pre-conditions like "okay to operate under a limited envelope" or now "could have landed from any point on a typical mission profile" are in fact completely meaningles

Those are defined conditions. They're only meaningless if you don't know the definitions, but the fact that you don't know common aviation terms or how they relate to the 787 isn't really Boeing's fault.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-06 06:30:51 and read 20544 times.

Quoting tdscanuck (Reply 41):
They're only meaningless if you don't know the definitions, but the fact that you don't know common aviation terms or how they relate to the 787 isn't really Boeing's fault.

Would you then be so kind as to explain us all what the typical mission profile is Boeing referred to in its statement, and also maybe what is an a-typical mission profile?

And since you're at it, maybe also specify the boundries of that limited flight envelope Boeing theoretically saw fit to uperate the 787 under when the structural issues in the wing-to-body join were discovered and they timidely announced a halt to the test program too?

Since you clearly know the exact definitions used by Boeing, may I respectfully ask to please share them with us all, so we needn't debate them any longer!?

Thanks for your any meaningful contribution and clearcut definition which is to be posted here soo now, including the reference to a Boeing document or statements to back it all up, all in an unambiguous relation to the issues discussed here of course, not simply assuming them to be referring to the same 'typical mission profile' Boeing may have used on other occasions....

[Edited 2010-12-06 06:40:01]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-06 06:57:50 and read 20303 times.

Quoting tdscanuc (Reply 39):
The *main* instruments are powered for 30 minutes by the ships battery. The standby instruments go for at least 30 minutes using their own internal battery. And, in either case, as soon as the RAT drops the critical instrument buses come back up and your time limit goes away. The batteries only need to carry you through until the RAT drops, not for the whole flight. Once the RAT drops, you've got primary flight display for as long as you're moving through the air.

What are you refering to as "critical insturment busses"? is it the L&R instruuments or the STBY insturments
Are you refering to primary instruments when you say: " you've got primary flight display for as long as you're moving through the air"? In other words the RAT powers the primary instrumets.

Rember that the FAA pilot had to land the aircraft because the R primary insturments failed, and that indicates to met that they only had standby instruments.

[Edited 2010-12-06 07:49:43]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: TheRedBaron
Posted 2010-12-06 07:59:56 and read 19816 times.

Quoting tdscanuck (Reply 41):
No, it's not a test mission profile. Just how stupid do you think Boeing is? You can't design complex systems without defining the requirements *early* in the process, including the typical mission profile. This stuff was all nailed down years ago.

Well Toyota thought they had nailed down the pedal accelerators and systems of their cars ( a lot less complex) and the failed. Remember stupidity and mistakes have been predicted by murphy's law since the beginning of mankind.

Maybe Boeing is not lying but consider this escenario:

1) You promise your girlfriend that the wedding date is October 2008
2) You delay the date 6 months
3) You delay the date 6 months
4) You delay the date 6 months
5)........You delay the date 6 months.....
....

....
....
9) You delay the date 6 months

Do you honestly she will believe you?....

(by delay number 3 she would be out of sight, and no matter how you spin it, she will think you are a liar.)

All this mumbo jumbo is only damage control for shareholders (exactly the same kind of dung John Leahy has done)

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rcair1
Posted 2010-12-06 08:42:00 and read 19707 times.

Quoting kaiarahi (Reply 39):
It would be nice ti live in a world without PR,

Oh - I would submit that most here would NOT like it.

If you define PR as portraying your side of the story in a way that supports your business, point, position, in order to build a relationship or connection with your target audience (a positive statement about PR),

or even a more negative version of

portraying your side of the story in a misleading way by choosing facts to include, facts to exclude and wording that is can be taken in multiple ways...

---
Then I would submit that the civil aviation forum on A.net would be a pretty quiet place. About 50% of what I have in this thread fits solidly in the second defn of PR. About 40% of it is restatements of previous positions using other words (PR), about 10% is factual, at best - most of that early on.

---
The 787 has faced significant delays - fact.

The 787 is treading on new technologies - stretching the limits of new technologies - fact (it will be interesting to read how the 787 is not doing that - probably in posts by those who say the 787 was "too much too soon").

Boeing has had to publicly deal with those delays, as have their customers, in a way that does not destroy their business, present or future - fact. (What would you expect them to do - say the 787 is a pos, that their engineers and suppliers are stupid and anybody who flies in it is an idiot?)

Boeing is purposely lying or misleading with intent to conspire to mislead the FAA and other regulatory agencies, and their customers, to purchase and fly an inherently unsafe aircraft. - opinion and hyperbola.

---
I'm not enough of an aviation history buff to know, nor do I have the time to spend looking at it, but it would be interesting to study and review the problems that "revolutionary" aircraft faced - whether they succeeded or not. Couple come to mind - Comet - failed. A320 - succeeded (even after a very public crash). Hughs flying boat - failed. 747 - succeeded. 707 - succeeded. 737 - succeeded (even after the rudder control valve problem). A380 - technical success (it appears), business, too soon to tell, Concorde - jury is out I think, Hustler - failed

---
I stupidly keep coming to this string to see if anything factual appears. Same with the A380 blown engine strings. What a fool am I   

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kaiarahi
Posted 2010-12-06 09:34:23 and read 19563 times.

Quoting rcair1 (Reply 46):
I stupidly keep coming to this string to see if anything factual appears. Same with the A380 blown engine strings.

I don't know when you looked at the QF A380 thread, but the official ATSB report has been posted for about 5 days.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-06 09:40:19 and read 19530 times.

Quoting slz396 (Reply 42):
Thanks for your any meaningful contribution and clearcut definition which is to be posted here soo now, including the reference to a Boeing document or statements to back it all up, all in an unambiguous relation to the issues discussed here of course, not simply assuming them to be referring to the same 'typical mission profile' Boeing may have used on other occasions....

I would also be interested in any documentation that contradicts any claims made by Boeing. For instance, typical mission profile doesn't specifically eliminate any mission the plane is contractually capable of. Do you have any data specifically laying out any mission that the aircraft would not have been capable of? By this I mean real information as opposed to supposition and opinion.

Surely there must be information refuting any statements made by Boeing. I believe, for example, Boeing decided not to fly their planes until the body join problem was fixed. The repair brought the wing up to original specs. If you have any information to the contrary, I would be interested in it.

Quoting slz396 (Reply 44):

Proof of my point really: all too many descriptors are used to avoid naming things by their proper name in an all too obvious effort to blow smoke and confuse people, thus leading them to assume certain things which aren't explicitly said so, should evidence on the contrary come out later.

I am curious as to why anyone in A.net feels that Boeing or anybody involved in the 787 program is obligated to inform them of anything. The only people they actually have to inform are regulators and customers. I really doubt either of them are posting on the subject.

If the regulators aren't contradicting Boeing, either they are in a nasty conspiracy with Boeing or perhaps Boeing is telling the truth.

Boeing doesn't build planes for our satisfaction and they are under no obligation to satisfy out curiosity. Basically if someone doesn't like it, tough nut...take it up with them.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kaiarahi
Posted 2010-12-06 10:03:41 and read 19458 times.

Quoting TheRedBaron (Reply 45):
Quoting tdscanuck (Reply 41):
No, it's not a test mission profile. Just how stupid do you think Boeing is? You can't design complex systems without defining the requirements *early* in the process, including the typical mission profile. This stuff was all nailed down years ago.

Well Toyota thought they had nailed down the pedal accelerators and systems of their cars ( a lot less complex) and the failed.

Apples and oranges. Toyota would have nailed down the "mission profile" of their vehicles (market segment, number of pax, cargo in the case of pick-ups, etc) long before a designer/engineer began working on accelerators (component) or fuel control software.

Quoting TheRedBaron (Reply 45):
Remember stupidity and mistakes have been predicted by murphy's law since the beginning of mankind.

I didn't realize Murphy was that old.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Revelation
Posted 2010-12-06 10:04:20 and read 19495 times.

Quoting slz396 (Reply 40):
Sure, the only difference being that is if comes from Boeing, half of airliners.net takes it as coming straight from the bible and reads far more in it than they actually just said, flaming anybody that dares to question the exact carry of those words!

That's a pretty ugly slur on the Bible and a personal insult to many a.net members, if you ask me.

Quoting slz396 (Reply 40):
Statements containing delimiting yet non-defined pre-conditions like "okay to operate under a limited envelope" or now "could have landed from any point on a typical mission profile" are in fact completely meaningles

What is "completely meaningless" about "could have landed from any point on a typical mission profile"? Sure, it doesn't say what could happen on an atypical mission profile, but that doesn't render it meaningless.

Quoting slz396 (Reply 40):
and do nothing but timidly admit that indeed the plane can not be flown safely in all conditions where it should be, despite looking as saying the opposite!

So now you are saying there is some meaning to be derived from the meaningless statement?

Quoting slz396 (Reply 40):
Very sobering to see how many people simply ignore all of these limitating preconditions and simply assume them to be excluding only very remote cases at worst, something which is nowhere said by Boeing, all while accusing others of not wanting to read carefully what was said.

Whatever, dude. If you want to presume Boeing's statements to be including each and every potential dire outcome that they do not explicitly rule out, it's your right.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: bikerthai
Posted 2010-12-06 10:37:02 and read 19372 times.

Quoting kaiarahi (Reply 49):
Apples and oranges. Toyota would have nailed down the "mission profile" of their vehicles (market segment, number of pax, cargo in the case of pick-ups, etc) long before a designer/engineer began working on accelerators (component) or fuel control software.

Apples and Oranges yes . . .
Example given does not prove the statement however.

Boeing did " nailed down the "mission profile" of their vehicles (market segment, number of pax, cargo in the case of pick-ups, etc) long before a designer/engineer began working"

It's the execution that is off.

A better example would be if you can provide an example of a flawless introduction of the Prius I vs the 787.

Another example would be to conclude that since Toyota put out a new model every 2-3 years vs every 10 years for Boeing or Airbus, they would know how to do it better . . . with fewer flaws or recall.

Conclusion? Retaining a knowledgeable and capable Engineering base is very important and very difficult in the modern age with such a long design cycle . . . filler . . .

bikerthai

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: litz
Posted 2010-12-06 10:54:22 and read 19327 times.

Quoting Stitch (Reply 1):
I really cannot believe that they designed a system with a single-point of failure in it.

I'm sure Carnival is asking the same exact question right now ...

(how odd was it that two completely different transportation systems had electrical fires the same week?)

- litz

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dynamicsguy
Posted 2010-12-06 11:44:12 and read 19238 times.

Quoting slz396 (Reply 42):
Since you clearly know the exact definitions used by Boeing, may I respectfully ask to please share them with us all, so we needn't debate them any longer!?

What is the point? Any time a term is explained for you, you ignore its meaning if it doesn't support your view of how an airplane is designed, manufactured and certified. And it is rarely respectful.

From a structures standpoint, we design to 3 typical mission profiles - a high cycle, short mission, a medium cycle medium length mission and a low cycle, long distance mission. These are based on how Boeing expects the airplane to be used in service.

I don't know why you expect Boeing to release to you proprietary information about how the flight envelope has been limited. And any Boeing employee would be an idiot to disclose such confidential information on a public forum like this.

[Edited 2010-12-06 12:13:52]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-06 11:48:22 and read 19224 times.

Quoting tdscanuck (Reply 41):
Quoting BoeingVista (Reply 36):
14. Asserting that the dead horse was still capable of fulfilling a typical mission profile

So we're just assuming they're lying now?

Nope, we are just cracking a joke. Humour is sometimes rough when it touches on things that we love but it is still humour, also in the words of Hommer Simpson, its funny because its true!

As has been pointed out by slz386 many of Boeings statements of late defy proper analysis because the limiting factors are not explained. If the typical horse mission was defined as bearing weight rather than moving weight a dead horse could indeed fulfill a typical mission profile, unless it is clearly stated what that mission profile is the statement is meaningless.

I am neither shocked nor surprised that most posters chose to ignore this, analytical thought is so passe in 21st century America but those of us brought up in an age and a place where questioning authority was encouraged (as blindly following tended to lead to wars and other unpleasantness) I find it odd, ok a little amusing too but odd.

[Edited 2010-12-06 11:49:33]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: AAExecPlat
Posted 2010-12-06 12:18:40 and read 19122 times.

Quoting Revelation (Reply 50):
That's a pretty ugly slur on the Bible and a personal insult to many a.net members, if you ask me.

No ugly slur. It's an American turn of phrase that he (as a non-native English speaker) slightly dismembered. I doubt he meant it as such even in the slightest. And by the by, bible scholars generally agree that at least parts of the Bible (i.e. letters in the New Testament) were a form of "code" that allowed different factions of the Christian community to communicate with each other without fear of detection from those who were persecuting them (i.e. the Romans).

Just thought I'd shine the light on the provenance of the turn of phrase our Belgian compadre unfortunately didn't utilize properly.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-06 12:33:41 and read 19048 times.

Quoting dynamicsguy (Reply 53):
What is the point? Any time a term is explained for you, you ignore its meaning if it doesn't support your distorted view of how an airplane is designed, manufactured and certified. And it is rarely respectful.

From a structures standpoint, we design to 3 typical mission profiles - a high cycle, short mission, a medium cycle medium length mission and a low cycle, long distance mission. These are based on how Boeing expects the airplane to be used in service.

I don't know why you expect Boeing to release to you proprietary information about how the flight envelope has been limited. And any Boeing employee would be an idiot to disclose it on a public forum like this.

Ok, which of these missions is typical? You seem to claim that there are 3 "typical" mission profiles

Which of these profiles is Boeing talking about in statement X, statement Y, statement Z etc, I have suspected for some time that there may be more than one "typical" mission profile.

I have also suspected for some time that we have AstroTurfers on A.net who spread confusion, misinformation and the company line and try to funnel threads and squash decent. Hey its a PR world, and believe it or not we have the potential to be opinion formers, if I was Boeing I'd hire AstroTurfers on A.net.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dynamicsguy
Posted 2010-12-06 12:42:27 and read 19017 times.

Quoting BoeingVista (Reply 56):
Ok, which of these missions is typical? You seem to claim that there are 3 "typical" mission profiles

They all are. Not every operator will use their airplanes the same way, so we have to run analysis to show the structure good for different scenarios. I should stress (no pun intended) that this is for fatigue design of structure. Other aspects of the design may use different or more varied missions.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-06 14:51:48 and read 18754 times.

Quoting BoeingVista (Reply 56):
Which of these profiles is Boeing talking about in statement X, statement Y, statement Z etc, I have suspected for some time that there may be more than one "typical" mission profile.

I have also suspected for some time that we have AstroTurfers on A.net who spread confusion, misinformation and the company line and try to funnel threads and squash decent. Hey its a PR world, and believe it or not we have the potential to be opinion formers, if I was Boeing I'd hire AstroTurfers on A.net.

Boeing isn't required to tell posters anything, including specifics about what is typical. Until someone comes up with any mission that could possibly considered typical, which the plane would have been unable to complete, then Boeing is not contradicted.

Why would Boeing bother with A.net secret moles? What would be the point? I really doubt there are any posters who have significant, (if any), influence on airliner purchasing. What is in it for Boeing? Most of the general public has no idea about A.net.

I can't imagine any airline purchasing exec. making their decisions based on what the read here. If an airline hires such people, I really wouldn't want to fly on that airline.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: keesje
Posted 2010-12-06 15:14:55 and read 18724 times.

Quoting Stitch (Reply 23):
Quoting 14ccKemiskt (Reply 20):
Seems like it has been raining in in the plane during tests flights.

It sounds like something endemic to CFRP fuselages as Airbus had noted they too have been working on condensation problems with A350XWB test barrels (I am guessing during environmental tests on them?).

Is this in anyway related to increased humity, a slelling point of the Dreamliner?

Quoting JoeCanuck (Reply 28):
Quoting BoeingVista (Reply 27):
Yeah, you're right that blows, do you think that as a community we can do anything about this?

We could go on strike...that'd learn 'em...

  

Quoting JoeCanuck (Reply 58):
What is in it for Boeing?


Nothing. Although recently I posted a thread on the 737-900ER becoming hard to market after 2015, including some good home made graphics with future competitors etc. http://www.airliners.net/aviation-fo...eneral_aviation/read.main/4907469/ Boeing marketing react with 2 days.
http://boeingblogs.com/randy/archives/2010/08/sharks_and_jets.html Wasn't the first time.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-06 15:24:31 and read 18651 times.

Quoting JoeCanuck (Reply 58):
Boeing isn't required to tell posters anything, including specifics about what is typical. Until someone comes up with any mission that could possibly considered typical, which the plane would have been unable to complete, then Boeing is not contradicted.

No actually, but this is exactly what I am talking about vis AstroTurf; you don't get to frame how I or others should consider Boeings statements we do this ourselves in our own minds, you have just attempted to make us prove Boeing is not telling the truth, shouldn't the onus be on Boeing to prove that it is telling the truth if there are doubts about the veracity of its statements? They are a listed company after all. Its hard to prove a negative [see Iraq and lack of WMD's even though none have been found in 10 years some still believe that they are there].

Posters don't have to prove anything but we say on the balance of past performance we do not believe their statements at face value. I don't have to prove gravity on a daily basis to know that my cup is not going to fly up off my table, I just know which way is up.

Quoting JoeCanuck (Reply 58):
Why would Boeing bother with A.net secret moles? What would be the point? I really doubt there are any posters who have significant, (if any), influence on airliner purchasing. What is in it for Boeing? Most of the general public has no idea about A.net.

Share price for one, rumours can move markets, rumours start on blogs, also because posts from enthusiast sites like this regularly make the news, I grant you that it is mostly from PPRUNE but occasionally post from here make it to blogs that make it to the news media. Flightblogger seems to have done quite well for him self who was a regular poster here before he was who he now is and {checks with lawyer} some have said he is too close to certain players in the industry.

I would be amazed if Boeing does not pay a media company to keep tabs on sites like these and steer discussions, case in point is the fire pictures, they all came down PDQ and from sites I had never heard of until they were mentioned on other blogs as getting legal letters from Boeing to remove the pictures, sorry mate but you lose that one!

Obviously the above is not a suggestion that Jon O is now or has ever been involved in AstroTurfing.

Anyway thread drift...........

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: thediplomat
Posted 2010-12-06 15:25:38 and read 18658 times.

Quoting keesje (Reply 59):
Boeing marketing react with 2 days.

Don't flatter yourself keesje. neither you nor anet has anywhere near that level of influence.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rcair1
Posted 2010-12-06 15:39:16 and read 18604 times.

Quoting kaiarahi (Reply 47):
I don't know when you looked at the QF A380 thread, but the official ATSB report has been posted for about 5 days.

Thanks - but I read it the day it came out. Kudos to them for being quick.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kanban
Posted 2010-12-06 15:55:36 and read 18577 times.

Quoting BoeingVista (Reply 54):
many of Boeings statements of late defy proper analysis because the limiting factors are not explained.



You (A.neters in general) obviously have no idea the process that creates these releases... all are run through a legal department to ensure they are as vague as possible without creating impressions that could be construed other than as stated. There is also PR branch that ensures the release causes no more harm than the facts warrant.. Between the two of them, it's lucky there are any releases.

The company is not required to answer every allegation, nor is it obligated to report investigation details .. Plus it really doesn't have time to monitor this site for ideas... Boeing security it does monitor it too ensure that company proprietary information is not divulged...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Zeke
Posted 2010-12-06 18:37:24 and read 18376 times.

Quoting packsonflight (Reply 5):
It would be nice if you could post here QRH checklist for "LOSS OF ALL AC BUSSES" or "DUAL ENGINE FAIL" specially the part of the dual engine failiure checklist that comes after" APU NOT AVAILABLE"
Normally there is a reading there which describes the condition the aircraft is in.

No checklist for loss of all AC busses, the dual engine fail/stall is very similar to the 777 one. Every aircraft that I am familiar with assumes this dual engine fail/stall happens in cruise, the checklists are normally built around trading height for forward speed, and using that forward speed to windmill the engines to start.

Quoting JoeCanuck (Reply 9):
Now, I agree it is possible that Boeing is lying but there was at least one FAA pilot in the cockpit, and the FAA is undoubtedly intimately involved in any analysis and fix. So far, the FAA has not publicly contradicted anything Boeing has said.

The FAA and Boeing need to be careful what they say. As with all aircraft accidents and incidents it is the role of the NTSB to investigate them. The manufacturer and regulator during the investigation process can only release information which the NTSB says it can release.

Quoting JoeCanuck (Reply 11):
There are always preconditions for every procedure. For example, one of the preconditions for a normal landing procedure is that the gear is down and locked. Is Boeing required to tell the posting public exactly what sequence of events has to take place in order to do that?

Boeing does include gear down on its checklists as an action required prior to landing.

Quoting JoeCanuck (Reply 11):
Airbus didn't have to tell the public their exact procedures for a #3 LP disc ejection creating massive holes in the fuel tanks, disabling or damaging 2 hydraulic systems and limiting the use of some flight controls...and I don't expect them to.

Those checklists do exist, engine failure with damage, fuel leak, slats locks, land distance calculation, hydraulic system low pressure etc are all available.

Quoting JoeCanuck (Reply 11):

I expect Airbus to make a plane robust enough to take unexpected damage and still land safely even though the crew wasn't specifically trained for that event...which they did. I expect the same from Boeing.

During their training they would have had even more challenging scenarios to deal with. What the training is doing is giving you a process to deal with any situation. That was not the first time an aircraft has had a catastrophic engine failure causing damage, and it will not be the last.

Quoting tdscanuck (Reply 15):
An onboard fire that self-extinguishes, doesn't threaten the pilots' ability to fly or operate the airplane, and leaves the plane in a configuration suitable for a 6+ hour diversion? Yes, I don't think that was luck.

No pilot is going to fly for 6 hours after an onboard fire with smoke that has entered the passenger cabin. The smoke, fire, or fumes checklists would direct the pilots to divert, not continue. Common sense would say declare a mayday and get yourself to the closest runway possible.

The other point to make is that with the RAT out, according to the manuals, the operation of the slats/flaps is limited. Fuel consumption would be around 2.5 times higher than normal, with cruise limited to below FL200. The 787 is supposed to have good range, however it would not have the range to fly for 6 hours with slats/flaps extended.

Quoting BoeingVista (Reply 19):
But the problem here is if the architecture is hidden from the guys doing the troubleshooting (Pilots) then they do not have the necessary information to make informed decisions, further I would contend that this shows the limits of auto configuration, smart system failover is good but if that auto failover fails where does that leave the guys at the pointy end?

Same place as usual, having to deal with a real emergency, in real time, at altitude, with a bunch of living people in the passenger cabin. All the crew will be focused on will be getting the aircraft to the ground, and getting the people out of it.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-06 18:42:12 and read 18356 times.

Quoting BoeingVista (Reply 60):
shouldn't the onus be on Boeing to prove that it is telling the truth if there are doubts about the veracity of its statements?

No. The onus should be on whomever is making an accusation to prove it...unless the accusations are coming from a regulatory entity such as the FAA or from customers with whom they have a legal contract.

They don't have to prove a darned thing to a.netters.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-06 21:22:42 and read 18194 times.

Quoting slz396 (Reply 42):
Would you then be so kind as to explain us all what the typical mission profile is Boeing referred to in its statement

The typical mission profile would be defined in the design requirements and objectives document, something that had to have been written before anyone even started designing the thing (it's probably 10 years old, at least, for a 787). That's a highly proprietary document so, even if I did have it (I don't), I wouldn't be posting pieces of it on a.net.

However, backing out the approximate typical mission profile is pretty easy from looking at airliner specifications. You can tell just by looking at the ACAP and marketing materials for a 787 that the typical mission is roughly 250 people for 6500-7000 nm.

Quoting slz396 (Reply 42):
and also maybe what is an a-typical mission profile?

Exit limit (probably 300+) for 500 nm. 150 people for 9000nm. Pretty much any test flight.

Quoting slz396 (Reply 42):
And since you're at it, maybe also specify the boundries of that limited flight envelope Boeing theoretically saw fit to uperate the 787 under when the structural issues in the wing-to-body join were discovered and they timidely announced a halt to the test program too?

The flight envelope, in the structural context that's relevant to the wing-body fix, is the plot of allowable Nz vs. GW (inside the curve good, outside the curve bad). This is a standard chart that's included in the flight handbook. The normal operation envelope is defined by FAR 25 Subpart C and is common to all transport category airplanes. Flight test normally operates with a slightly larger envelope to ensure that the true performance remains in the certified envelope.

A reduced flight envelope, in the structural context, is pulling the curves in so that, for any particular GW, you can't pull as much Nz as the original envelope. It's a normal way to deal with uncertainties in structural design (you operate this way until flutter and static strength are complete, for example).

There's another type of flight envelope (they're complimentary) that relates speed to altitude...which envelope you're talking about depends on the context.

Quoting slz396 (Reply 42):
Since you clearly know the exact definitions used by Boeing, may I respectfully ask to please share them with us all, so we needn't debate them any longer!?

You need to pick which argument you're trying to make...originally it was that Boeing's statements were "meaningless" because they used terms that you believed don't have a clear definition. My point was that the terms *do* have a clear definition, hence Boeing's statements aren't meaningless.

That's *very* different from demanding to know the exact definition used by Boeing...knowing it to reasonable tolerances is pretty easy by looking at published data (ACAP, FAR's, etc.). Knowing it exactly would require release of proprietary data, which no OEM is going to do and I certainly wouldn't do, even if I did have it.

If you're arguing that Boeing didn't provide the precise definitions, you're absolutely right...but that's not relevant to knowing the meaning of Boeing's public statements and it's also not something that any OEM would ever do.

Quoting slz396 (Reply 42):
Thanks for your any meaningful contribution and clearcut definition which is to be posted here soo now, including the reference to a Boeing document or statements to back it all up, all in an unambiguous relation to the issues discussed here of course, not simply assuming them to be referring to the same 'typical mission profile' Boeing may have used on other occasions....

Typical mission profile: 787-8 Design Requirements & Objectives document
Flight Envelope: 787-8 AFM & FAR 25 Subpart C

Quoting packsonflight (Reply 43):
What are you refering to as "critical insturment busses"? is it the L&R instruuments or the STBY insturments

I was referring to the stuff powered by the RAT, which includes the L&R instruments and the standby instruments.

Quoting packsonflight (Reply 43):
Are you refering to primary instruments when you say: " you've got primary flight display for as long as you're moving through the air"? In other words the RAT powers the primary instrumets.

The RAT powers both the primary instruments and, by providing charging to the standby battery, the standby instruments.

Quoting packsonflight (Reply 43):
Rember that the FAA pilot had to land the aircraft because the R primary insturments failed, and that indicates to met that they only had standby instruments.

You have fully redundant primary instruments (L & R) and the standby instrument (a self-contained ILS/attitude/airspeed/altitude instrument dead center on the panel). Loss of the R primary instruments still leaves you with L primary instruments, which is not the same thing as standby instruments.

Quoting slz396 (Reply 44):
Quoting packsonflight (Reply 43):
What are you refering to as "critical insturment busses"?

There you have it...
ANOTHER robust sounding, but extremely vague and confusing terminology is being used.

Yes, it would have been clearer if I'd specified exactly what I meant by "critical instrument buses." I meant what's powered by the RAT. However, if I'd just said "what's powered by the RAT" then it would have been useless to anyone who doesn't have access to the documentation to identify exactly what's powered by the RAT, so that didn't seem to be particularly helpful.

Quoting slz396 (Reply 44):
Proof of my point really: all too many descriptors are used to avoid naming things by their proper name in an all too obvious effort to blow smoke and confuse people

"Typical mission profile", "flight envelope" and "primary instruments" *are* the proper names. What else do you want them to be called?

Quoting slz396 (Reply 44):
"Critical busses" have a proper name too in the FCOM...
Can you please use that name so we might be able to see just what was powered and what not???

From now on, when I say "critical buses" just mentally replace that with "everything powered by the RAT."

Quoting slz396 (Reply 44):
Because 'primary flight displays' is way too vague too

No, it's not. The primary flight display is a very concrete, very definite, straight-from-the-FCOM term for a specific flight deck display that is instantly clear to any pilot familiar with modern glass cockpit design. In the case of the 787, you have two PFD's (L & R), one EICAS, and 5 MFD's.

Quoting BoeingVista (Reply 54):
As has been pointed out by slz386 many of Boeings statements of late defy proper analysis because the limiting factors are not explained.

I agree that some of the PR statements are vague. As kanban very correctly pointed out, there are reasons for that and there's not a whole lot any of us here can do about it. However, some of the issues that slz386 is accusing of being "vague" and "meaningless" are, in fact, very clear. If you don't know the definition behind what is a well defined term, then it certainly looks meaningless. But the issue isn't that it's a meaningless statement, it's just that you don't know what the definition is. I'm trying to fix that, with very mixed results.

Quoting BoeingVista (Reply 54):
If the typical horse mission was defined as bearing weight rather than moving weight a dead horse could indeed fulfill a typical mission profile, unless it is clearly stated what that mission profile is the statement is meaningless.

They did clearly state it. "Typical mission profile" is a clear and unambiguous statement to anyone who's used to looking at mission profiles and airliner design.

Quoting BoeingVista (Reply 56):
Ok, which of these missions is typical? You seem to claim that there are 3 "typical" mission profiles

The typical mission, in the context of the Boeing PR release, is the median mission. You can get that by taking the design life in years, cycles, and hours, which will give you the average flights per day and the average hours per flight. Coupled with the cruising speed, that gives you the average range per flight (modulo the reserves) and, putting that into the ACAP, you get the average payload per flight.

In the structural context, which is what you were asking about, missions are divided into three buckets (short, medium, and long) and typical values are identified for each. This lets the structural guys figure out what the damage tolerance analysis has to be like depending on what mix of short/medium/long missions any particular operator uses.

Someone like Air New Zealand is going to be living in a very different part of the cycles/hours space than someone like ANA running domestic widebodies.

Quoting BoeingVista (Reply 56):
Which of these profiles is Boeing talking about in statement X, statement Y, statement Z etc, I have suspected for some time that there may be more than one "typical" mission profile.

In the context of diversion, which is what we're talking about here (and Boeing were talking about in their press release), it's the median mission (the one on which the plane spends most of its time).

Quoting keesje (Reply 59):
Quoting Stitch (Reply 23):
Quoting 14ccKemiskt (Reply 20):
Seems like it has been raining in in the plane during tests flights.

It sounds like something endemic to CFRP fuselages as Airbus had noted they too have been working on condensation problems with A350XWB test barrels (I am guessing during environmental tests on them?).

Is this in anyway related to increased humity, a slelling point of the Dreamliner?

Humidity definitely makes it worse, so that's probably a contributer. Although CFRP is more insulating than aluminum, which should help with condensation, so I'm not sure which way that trade ends up tipping.

Quoting BoeingVista (Reply 60):
you don't get to frame how I or others should consider Boeings statements we do this ourselves in our own minds, you have just attempted to make us prove Boeing is not telling the truth, shouldn't the onus be on Boeing to prove that it is telling the truth if there are doubts about the veracity of its statements?

I think the onus should be on people checking if the terms are defined before declaring Boeing's statements to be meaningless. If you don't know what something means, ask. Maybe it's PR-speak, maybe it means something. Assuming it means nothing is just muddying an already very muddy pond.

Quoting Zeke (Reply 64):
The other point to make is that with the RAT out, according to the manuals, the operation of the slats/flaps is limited. Fuel consumption would be around 2.5 times higher than normal, with cruise limited to below FL200. The 787 is supposed to have good range, however it would not have the range to fly for 6 hours with slats/flaps extended.

You lost me Zeke...If you had slats/flaps out, you'd be on approach so why would you do a 6 hour divert? If you lost power in cruise (which is where you'd expect a divert of that nature), you'd have to descend but you'd still be in clean configuration. Proper ETOPS flight planning would dictate that you've got enough fuel to reach your worst-case alternate from that point, and the RAT would keep your electricals and hydraulics alive the entire time.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 01:21:54 and read 17961 times.

Quoting BoeingVista (Reply 53):
As has been pointed out by slz386 many of Boeings statements of late defy proper analysis because the limiting factors are not explained. If the typical horse mission was defined as bearing weight rather than moving weight a dead horse could indeed fulfill a typical mission profile, unless it is clearly stated what that mission profile is the statement is meaningless.

Indeed and yet this undeniable observation apparently greatly annoys certain people here, who absolutely want to proof that this is not the case and who go to great lenghts trying to do just that... weird, isn't it?

The more they try to explain what was ment however, the more it becomes all too obvious they are just beating around the bush really, avoiding to nail down things to specific factual elements, rather than use robust sounding but equally hollow words which have no strictly defined meaning in the context of this discussion, other than the ones they'd want you to give them.

It's a clear pattern and when detected, somebody who's trained in analytical reading will notice it and draw the only correct conclusion from it: you Sir, are definitely one of them.

Quoting BoeingVista (Reply 59):
this is exactly what I am talking about vis AstroTurf; you don't get to frame how I or others should consider Boeings statements, we do this ourselves in our own minds; you have just attempted to make us prove Boeing is not telling the truth, shouldn't the onus be on Boeing to prove that it is telling the truth if there are doubts about the veracity of its statements?

Indeed, some here seem to be VERY concerned others may start to think we do have a point, as if they have some interest in making sure the 'good line' is kept... weird, isnt it?

Interestingly to note too how some people seem to be convinced they can speak on behalf of Boeing, since they are fully able to explain exactly just what was ment with each of those undisputably very vague and ambiguous statement, often able to pick the 'right' option from several possibilities even! weird, isn't it?

Quoting BoeingVista (Reply 53):
I am neither shocked nor surprised that most posters chose to ignore this, analytical thought is so passe in 21st century America but those of us brought up in an age and a place where questioning authority was encouraged I find it odd, ok a little amusing too but odd.

Neither am I.

Quoting JoeCanuck (Reply 57):
Boeing isn't required to tell posters anything, including specifics about what is typical.

They aren't required to do so indeed, but they keep talking nevertheless and if they do, they may as well say something meaningful then. If not, at least we're entitled to point out they are talking without saying anything at all, are we, as well as draw the obvious conclusion from it then? Or is that what really should be avoided at all cost?

Quoting BoeingVista (Reply 59):
I would be amazed if Boeing does not pay a media company to keep tabs on sites like these and steer discussions, case in point is the fire pictures, they all came down PDQ and from sites I had never heard of until they were mentioned on other blogs as getting legal letters from Boeing to remove the pictures, sorry mate but you lose that one!

Yes, they sure do and you can bet your life they have several people around here too, trying to steer discussions in the right direction!

This is by far the word's most popular aviation discussion forum which has great infulence on how commerical publications report on all the 787 mishaps, so it would be stupid if Boeing were not to follow what is posted here, and if they follow the discussions, they may as well participate in them, trying to steer them into a more favourable direction.

If you've spent tens of millions on marketing the 787 also through all sort of ads in popular publications, then stimulating some people to post favourably on what is going on right now, is just a logical next step to do...

[Edited 2010-12-07 01:23:16]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 01:42:21 and read 17903 times.

Quoting tdscanuck (Reply 65):
You can tell just by looking at the ACAP and marketing materials for a 787 that the typical mission is roughly 250 people for 6500-7000 nm.

Sir, the number of pax on board nor the length of the intended flightpath is relevant in case of an electrical fire taking out pretty much the entire 'normal' electrical system! What is going to be relevant to a safe conduct of the rest of the diverted flight is the environment you're in as well as the on board conditions:

icing on route and ice build up on both the airframe and the deployed RAT as well as the ability to still protect agains it

higher fuel burn and thus reduced endurance because of the above

lower flight levels to be flown at and the flight conditions there

remaining fuel and oxygen reserves

speed restrictions due to a decent

impact on ETOPS

weather conditions at destination as well as alternates

successful moke removal from the cabin (not a minor issue BTW)

electrical load shedding and its consequences on the cabin (heating, pressu, oxygen, humidity)

IMC or VMC

day or night flight

and more stuff like that....

Any real world combination of those is what will make up a typical mission profile in the context of the on board electrical fire, not the number of paying pax in C and Y class, or the length of intended flightpath as you've been pretending for the past 50 posts now. That's a typical mission profile in relation to flight planning, but it has nothing to do with a typical mission profile in relation to failure management in case of an emergency!

[Edited 2010-12-07 01:42:59]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-07 02:32:34 and read 17792 times.

Quoting slz396 (Reply 67):
icing on route and ice build up on both the airframe and the deployed RAT as well as the ability to still protect agains it

Good point!
If you are down to RAT power only, you can not enter icing condition since the RAT has no anti-ice and would stop working, resulting in totally uncontrollable aircraft.

I would say icing condition should be a part of the 787 "typical mission profile" since the aircraft must be certified for flight in to known icing

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: XT6Wagon
Posted 2010-12-07 02:46:29 and read 17778 times.

Quoting packsonflight (Reply 68):
Good point!
If you are down to RAT power only, you can not enter icing condition since the RAT has no anti-ice and would stop working, resulting in totally uncontrollable aircraft.

uh, pointless point. If you fly in icing conditions for over 30min... you are doing something very wrong. If the RAT fails you still have battery power at a minimum. We are starting to talk about events that are on the order of winning 3 jackpot lottos in the same day kind of odds.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-07 02:54:44 and read 17762 times.

Quoting slz396 (Reply 66):
I was referring to the stuff powered by the RAT, which includes the L&R instruments and the standby instruments.



The RAT does not power the L&R instruments, and I am pretty sure it does not power the standby instruments either. (standby instruments are powered from hot battery bus)

If the RAT would power L&R instruments, why was the R PFD (primary flight display) black?? since L primary instruments are accessible to copilot through instruments switching, and Boeing test pilot occupying the right seat knows about instrument switching.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 02:58:53 and read 17736 times.

Quoting XT6Wagon (Reply 69):
We are starting to talk about events that are on the order of winning 3 jackpot lottos in the same day kind of odds.

we are starting to talk events as on any normal transtatlantic trip during winter.

Quoting XT6Wagon (Reply 69):
If you fly in icing conditions for over 30min... you are doing something very wrong. If the RAT fails you still have battery power at a minimum

Image the same problem would have happened on an oceanic crossing and let's still be gentle, just 2 hours before landing.

Here's the setting:
The fire is self-exinghuished but all GENS are lost, so the RAT has dropped and the plane has to decent as a consequence, thus entering icing conditions at those lower levels. Completely unimaginable, right?

Oh, even if the RAT freezes, you still have battery power left....   

but only for 30 minutes   

and we were 2 hours away from landing still, while flying lower/slower!  

Able to continue from any point on a typical mission profile, right?   

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: keesje
Posted 2010-12-07 03:00:14 and read 17755 times.

Quoting thediplomat (Reply 60):
Quoting keesje (Reply 59):
Boeing marketing react with 2 days.

Don't flatter yourself keesje. neither you nor anet has anywhere near that level of influence.

Of course I have no influence at all. I'm just noticing Boeing marketing reacted, nothing more nothing less. In the past Boeing even confirmed themselves, I can look it up if you want  

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 03:02:36 and read 17724 times.

Quoting packsonflight (Reply 70):
Quoting slz396 (Reply 66):
I was referring to the stuff powered by the RAT, which includes the L&R instruments and the standby instruments.

You've quoted the wrong person here... that's a quote from tdscanuck's post.

I know it's a website problem, but just wanted to point it out once more.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 03:13:23 and read 17705 times.

Quoting keesje (Reply 72):
I'm just noticing Boeing marketing reacted, nothing more nothing less. In the past Boeing even confirmed themselves, I can look it up if you wan

It is well known they DO read what is written here, and they steer their comments in respect to it. That much is a given.

I should hope they will read what is said here too, and be forthcoming in telling whether or not the same incident would have let the plane to just continuing to MNL for instance, on a flight from SFO (the typical point-to point mission profile), it if would have happened mid Pacific, in wintertime, with icing from let's say FL220 down.

After all, they have already suggested it, when referring to a typical mission profile? Or didn't they?

  

[Edited 2010-12-07 03:18:16]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-07 03:18:56 and read 17680 times.

Quoting slz396 (Reply 66):

They aren't required to do so indeed, but they keep talking nevertheless and if they do, they may as well say something meaningful then. If not, at least we're entitled to point out they are talking without saying anything at all, are we, as well as draw the obvious conclusion from it then? Or is that what really should be avoided at all cost?

They are saying something meaningful...to most people. Judging from this thread alone, most posters have taken meaning from Boeing statements...so, by definition, they are saying something meaningful. Perhaps you mean they should only say things you agree with. Somehow, I doubt that can ever happen.

Do you have any information which specifically contradicts anything Boeing has said? Obviously many people can discern a logical meaning from Boeing statements. Perhaps you should consider it is not the statement which is the problem, but the interpretation. If more clarity is required, perhaps best take any questions directly to Boeing.

Besides, I'm not sure what your point is. Are you attempting to point out a Boeing lie? If so, what is it? You seem very sure that Boeing is up to some evil...what do you think that is? What are you attempting to convince people of? ...and why?

I may be wrong but I don't think I have ever read a positive statement you have made on anything related to the 787, so why do you have so many 787 related posts?

I wouldn't dream of trying to censor you, by any means. Everyone is welcome to their opinion. Your opinions of Boeing and the 787 are abundantly clear to anyone who can read...but I am having trouble understanding the point.

No opinion stated on A.net is going to change anything Boeing says or does...and it seems no statement by Boeing will satisfy every A.net member.

Still, regardless of any hard feelings created, Boeing makes statements for reasons of their own and the company isn't required to satisfy or soothe a.net posters.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rheinwaldner
Posted 2010-12-07 03:59:54 and read 17628 times.

Quoting slz396 (Reply 71):
The fire is self-exinghuished but all GENS are lost, so the RAT has dropped and the plane has to decent as a consequence, thus entering icing conditions at those lower levels.

On RAT only there is also no pressuration on the 787. But pressuration is a must to stay above icing conditions.

On lower FL's power is not enough for the anti icing systems and on higher FL's power is not enough for pressuration.

That leaves very few options for further cruising.

- Or - RAT-only-flight is a condition that must be prevented at all cost because it is never acceptable to happen.

Which may be an indicator for the troubles Boeing is in. Because it did happen.

At any time in the future the FOD could come from an engine that has an uncontained engine failure (see Qantas). It is too cheap just saying that no FOD will ever occur again and thus no fire will ever occur again and thus no knockout of all regular electrical power will ever occur again.

And if one failing panel knocks out the other too even the APU would not help much. Chances are high that power from the APU will not reach the consumers too.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Revelation
Posted 2010-12-07 04:18:36 and read 17676 times.

Quoting tdscanuck (Reply 65):
If you're arguing that Boeing didn't provide the precise definitions, you're absolutely right...but that's not relevant to knowing the meaning of Boeing's public statements

Indeed. Thanks for your patience, Tom, in providing as much information as you have.

Quoting slz396 (Reply 66):
It's a clear pattern and when detected, somebody who's trained in analytical reading will notice it and draw the only correct conclusion from it:

I wouldn't describe your rendering as analytical, I'd call it contrarian. You do not buy yourself any credibility by time and time asserting something is "meaningless" when the vast majority of people here clearly understand the meaning of Boeing's statements.

To continue to assert time and again that there must be something amiss since Boeing hasn't explained everything to your personal satisfaction is absurd, IMHO.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 04:33:28 and read 17617 times.

Quoting JoeCanuck (Reply 75):
Do you have any information which specifically contradicts anything Boeing has said? Are you attempting to point out a Boeing lie?

Several posters have come up with perfectly plausible real world situations any long haul plane can encounter on a day-to-day mission, situations which are clearly not fitting very well that said typical mission profile the 787 was allegedly still perfectly capable of even after the electrical fire and subsequent failures, although I'd say all of those situations are fairly typical indeed, don't you agree?

The conclusions from this are up to you really...

Quoting JoeCanuck (Reply 75):
If more clarity is required, perhaps best take any questions directly to Boeing

All those people who have serious questions and even operational problems with the reassuring comments Boeing have made with regard to the electrical fire and allt that has followed, should not just shut up while letting any misunderstandings or remaining ambiguities in place....

They have the right to highlight their concerns and ask others for their opinion, including through public forums, even if that puts into question the reassuring official comments from Boeing itself.

Quoting JoeCanuck (Reply 75):
What are you attempting to convince people of? ...and why?

See above.

Quoting JoeCanuck (Reply 75):
I wouldn't dream of trying to censor you, by any means. Everyone is welcome to their opinion. Your opinions of Boeing and the 787 are abundantly clear to anyone who can read.

so what is the problem then for you to ask me why I bother posting here???

The fact that I may convince others that just maybe indeed, my opinion on the matter could indeed be nearer the truth than what Boeing has said about it and than what some try very hard to deny?

[Edited 2010-12-07 04:48:51]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 04:41:34 and read 17569 times.

Quoting Revelation (Reply 77):
You do not buy yourself any credibility by time and time asserting something is "meaningless" when the vast majority of people here clearly understand the meaning of Boeing's statements.

The number of people buying a certain explanation is irrelevant as proof of its truth....

Besides, credibility is gained by making valid points, not by pleasing the majority with saying what they want to hear.

Quoting Revelation (Reply 77):
To continue to assert time and again that there must be something amiss since Boeing hasn't explained everything to your personal satisfaction is absurd, IMHO

Nothing absurd at asking to be specific, rather than despritive, or to name things by their proper name.
Failure to do so repeatetly does indicate that one is very bussy trying to give a better impression to reality, by letting readers assume certain things which aren't explicitly said but come in very handy if one wants to minimize the problem at hands.

As Zeke, sabena pilot, Rheinwhadner and others have shown in this and the 2 other threads, there are some very serious technical and operational problems with the generally accepted interpretation of the exact meaning of Boeing's statements,so maybe that interpretation isn't so correct after all, despite being quite widespread?

But since I agree it is a very favourable interpretation, I can understand why some wouldn't want to see it evolve....

[Edited 2010-12-07 04:50:09]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 04:54:57 and read 17541 times.

Quoting rheinwaldner (Reply 76):
On RAT only there is also no pressuration on the 787. But pressuration is a must to stay above icing conditions.

On lower FL's power is not enough for the anti icing systems and on higher FL's power is not enough for pressuration.

That leaves very few options for further cruising.

- Or - RAT-only-flight is a condition that must be prevented at all cost because it is never acceptable to happen.

Which may be an indicator for the troubles Boeing is in. Because it did happen

Yet according to Boeing, they were capable of a continued safe flight from any point on a typical mission profile, right?   

There seem to be an awful lot of preconditions to that typical mission profile for that statement to hold any grounds still, to the point where one can question just how typical it still is really.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Revelation
Posted 2010-12-07 05:26:23 and read 17469 times.

Quoting slz396 (Reply 79):
Failure to do so repeatetly does indicate that one is very bussy trying to give a better impression to reality, by letting readers assume certain things which aren't explicitly said but come in very handy if one wants to minimize the problem at hands.

Failure to retract your statement about "meaningless" comments when their meaning has repeatedly been explained to you also comes in handy when one wants to maximize the problem at hand.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-07 06:30:33 and read 17382 times.

Quoting slz396 (Reply 67):
Sir, the number of pax on board nor the length of the intended flightpath is relevant in case of an electrical fire taking out pretty much the entire 'normal' electrical system! What is going to be relevant to a safe conduct of the rest of the diverted flight is the environment you're in as well as the on board conditions:

Agreed.

Quoting slz396 (Reply 67):
icing on route and ice build up on both the airframe and the deployed RAT as well as the ability to still protect agains it

Why does this icing red-herring keep coming up? Natural icing tests are done *with anti-ice off*.

Quoting slz396 (Reply 67):
higher fuel burn and thus reduced endurance because of the above

lower flight levels to be flown at and the flight conditions there

remaining fuel and oxygen reserves

speed restrictions due to a decent

impact on ETOPS

weather conditions at destination as well as alternates

*All* of the above is included in the flight planning. "Typical mission profile" obviously (or hopefully obviously) includes a flight plan that's actually legal, which includes consideration for *everything* you've listed in this block. Some of the dispatchers on a.net can jump in here if they wish, but I don't know any dispatcher worth their salt that would release a flight plan that didn't cover everything you've listed.

Quoting slz396 (Reply 67):
successful moke removal from the cabin (not a minor issue BTW)

Commercial aircraft are certified for smoke penetration testing. Part of smoke containment on any aircraft are the interior panels...which ZA002 doesn't have. There's a reason that Flightbloggger's "better know a Dreamliner" series put the smoke testing on ZA003, the plane that actually does have an interior. Smoke penetration *can't* be an issue on the delivered configuration, or you wouldn't be able to deliver it.

Quoting slz396 (Reply 67):
electrical load shedding and its consequences on the cabin (heating, pressu, oxygen, humidity)

IMC or VMC

day or night flight

and more stuff like that....

*All* included in the flight planning. IMC/VMC makes no difference to duration (it does impact planned reserves, but not actual fuel required). They had instruments, so IMC is fine. Ditto night fligh.

Quoting packsonflight (Reply 68):
If you are down to RAT power only, you can not enter icing condition since the RAT has no anti-ice and would stop working, resulting in totally uncontrollable aircraft.

Engine fans don't have anti-ice either...engines must stop working when they fly in icing conditions. Wait a minute...

Quoting packsonflight (Reply 70):
The RAT does not power the L&R instruments, and I am pretty sure it does not power the standby instruments either. (standby instruments are powered from hot battery bus)

The RAT powers the L&R instruments. If it doesn't power the standby, L, or R instruments, exactly what do you think it does power?

Quoting packsonflight (Reply 70):
If the RAT would power L&R instruments, why was the R PFD (primary flight display) black?? since L primary instruments are accessible to copilot through instruments switching, and Boeing test pilot occupying the right seat knows about instrument switching.

I think you're mixing the sources with the displays. The L primary instrument *sources* are available to the F/O via instrument switching. If the L displays die, then it doesn't matter which source you connect to, you won't see anything on the L side.

Unless the RAT deployed instantly, you'd expect blank displays while the whole event was happening and the power system was freaking out. Power reconfigurations (and displays startup, and especially startup of the avionics driving the displays) takes time.

Quoting slz396 (Reply 71):
The fire is self-exinghuished but all GENS are lost, so the RAT has dropped and the plane has to decent as a consequence, thus entering icing conditions at those lower levels. Completely unimaginable, right?

Absolutely imaginable. And also completely covered by existing design. If it weren't, no ETOPS twin, including the A330 and 777, would be certifiable.

Quoting slz396 (Reply 71):
Oh, even if the RAT freezes, you still have battery power left....   

but only for 30 minutes   

and we were 2 hours away from landing still, while flying lower/slower!  

Able to continue from any point on a typical mission profile, right?   

Yes, because you're making a bad assumption...that the RAT won't operate in icing conditions. You're also making another tacit assumption...that the plane was *stuck* on RAT power. Given the altitude of the event on final approach, they were obviously going to continue to landing. Although Boeing has been very mum on this topic, we have no concrete evidence for what state the airplane would be in if the event happened at cruise and the flight crew had time to process all the messages. From 600' AGL to landing isn't enough time for most avionics systems to fully restart, or an APU start.

Quoting slz396 (Reply 78):
Several posters have come up with perfectly plausible real world situations any long haul plane can encounter on a day-to-day mission, situations which are clearly not fitting very well that said typical mission profile the 787 was allegedly still perfectly capable of even after the electrical fire and subsequent failures

Um, no. Several posters have come up with some plausible real-world scenarios and mistakenly assumed that the plane can't handle them given the available evidence. I've tried to point out those mistaken assumptions when I've seen them. So far, I've only seen one kinds of scenario...those where the plane (and, in fact, any ETOPS twin) can handle it given the information we have about the configuration the aircraft ended up in. If I missed a scenario, please bring it back up so we can chase it to ground.

Quoting slz396 (Reply 79):
Nothing absurd at asking to be specific, rather than despritive, or to name things by their proper name.

Absolutely agreed. But when you think that something like "primary flight display" is not specific, not descriptive, and not the proper name, I'm really at a loss as to what to do next.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rottenray
Posted 2010-12-07 07:17:16 and read 17302 times.

The last 20 or so posts are amusing and amazing, based on the facts of what happened.


Several folks are conveniently ignoring when the smoke and fire occurred - which was MOMENTS before landing.

That no effort was made to revive the electrical system seems, in the minds of some posting here, to equal a complete lack of ability to do so, which therefore means that Boeing is absolutely lying through their teeth when they state the 787 could have accomplished a safe landing within any assumed typical mission profile.

Agendas, et cetera.

But here's an interesting thought: When someone writes "Image the same problem would have happened on an oceanic crossing and let's still be gentle, just 2 hours before landing" at least ONE logical conclusion would be that the crew would have had 2 hours to work the issue.




Quoting tdscanuck (Reply 82):
Power reconfigurations (and displays startup, and especially startup of the avionics driving the displays) takes time.


  

If this failure had occurred WITHOUT smoke and fire, perhaps the crew would have done a go-around and made the time to run checklists, consult with tech personnel on the ground, et cetera in an effort to learn more about the failure.

There was smoke, they were on final approach, so they took the safest path - land immediately.




Quoting rheinwaldner (Reply 76):
At any time in the future the FOD could come from an engine that has an uncontained engine failure (see Qantas). It is too cheap just saying that no FOD will ever occur again and thus no fire will ever occur again and thus no knockout of all regular electrical power will ever occur again.


"FOD" is a term which encompasses a lot.

In this case, the FOD in question was something already inside the fuse, in a place where it didn't belong.

If a chunk of turbine disc comes whizzing through the P100, there will be a lot of other problems to consider.

That's an event you can't even design for, if you're building an airplane light enough to actually fly.

As far as FOD occurring again, we have to remember that these test aircraft suffer the presence of many more engineers with tools and other bits which can be lost or forgotten than an aircraft in normal service.



Cheers!

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Zeke
Posted 2010-12-07 07:25:46 and read 17272 times.

Quoting tdscanuck (Reply 65):
The RAT powers both the primary instruments and, by providing charging to the standby battery, the standby instruments.

What do you mean by "primary instruments", I have previously listed the DUs (as well as other systems) available with the RAT, the FO outer and inner DUs are blank. Hence the reason why the FAA pilot in the LHS made the landing on the day, and the Boeing pilot in charge of the flight in the RHS had no displays.

Quoting tdscanuck (Reply 65):
You have fully redundant primary instruments (L & R) and the standby instrument (a self-contained ILS/attitude/airspeed/altitude instrument dead center on the panel). Loss of the R primary instruments still leaves you with L primary instruments, which is not the same thing as standby instruments.

The FCOM does not talk about L & R primary instruments when powered by the RAT, just the inner and outer DU, and the lower DU. Information can be projected onto those DUs, including the PFD representation. The days have long gone when a single DU is restricted to displaying one item.

Quoting tdscanuck (Reply 65):
The primary flight display is a very concrete, very definite, straight-from-the-FCOM term for a specific flight deck display that is instantly clear to any pilot familiar with modern glass cockpit design. In the case of the 787, you have two PFD's (L & R), one EICAS, and 5 MFD's.

Not when the RAT is deployed.

Quoting tdscanuck (Reply 65):
You lost me Zeke...If you had slats/flaps out, you'd be on approach so why would you do a 6 hour divert? If you lost power in cruise (which is where you'd expect a divert of that nature), you'd have to descend but you'd still be in clean configuration. Proper ETOPS flight planning would dictate that you've got enough fuel to reach your worst-case alternate from that point, and the RAT would keep your electricals and hydraulics alive the entire time.

The Boeing statement talks about the configuration it had when it concluded the event, not in the cruise.

Anyone in the industry when describing an aircrafts configuration are describing the flap/slat/gear positions. e.g. takeoff configuration, cruise configuration, approach configuration, or landing configuration. The aircraft was in approach configuration when he RAT deployed, it was not able to go into the normal landing or cruise configuration. The aircraft was not in a configuration that would allow it to fly that far at all due to he increased fuel consumption.

The the FMC predictions in the configuration they aircraft was are wrong. They all assume that the aircraft will be clean, they do not take into account the 250% higher fuel burn. The Boeing statement of Nov 16, "The airplane concluded the event in a configuration that could have been sustained for the time required to return to an airport suitable for landing from any point in a typical 787 mission profile" is very misleading to be generous.

It was in a configuration that it could never have flown from "any point in a typical 787 mission", the aircraft would have run out of fuel. Also as far as I am aware, no fire protection is available in the area the fire occurred.

Quoting packsonflight (Reply 68):
If you are down to RAT power only, you can not enter icing condition since the RAT has no anti-ice and would stop working, resulting in totally uncontrollable aircraft.

No, the RAT will not ICE up.

Quoting packsonflight (Reply 70):
The RAT does not power the L&R instruments, and I am pretty sure it does not power the standby instruments either. (standby instruments are powered from hot battery bus)

The RAT does not power the FO out and inner displays,the HUDs, or some radios. It does power the the captains outer and inner DU, as well as in the lower DU. These displays are powered by the battery while the RAT is being deployed.

Quoting packsonflight (Reply 70):
If the RAT would power L&R instruments, why was the R PFD (primary flight display) black?? since L primary instruments are accessible to copilot through instruments switching, and Boeing test pilot occupying the right seat knows about instrument switching.

One would never do instrument switching in such a situation, as for a momentary period of time, no-one would have any displays. It is irrelevant anyway, the FOs DUs are not powered when the RAT is deployed.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 07:33:29 and read 17257 times.

Quoting tdscanuck (Reply 82):
Natural icing tests are done *with anti-ice off*.

Natural icing tests are NOT centered on a plane with its RAT down and take into account moderate icing conditions only.

Quoting tdscanuck (Reply 82):
*All* of the above is included in the flight planning.

Actually, only with reference to a one engine out situation, not to this very exceptional electrical situation.

Besides, it's interesting to note how this plane went straight from a perfectly normal situation to a full blown electrical emergeny level, something which NO flight planning needs to account for. You do not need to assume several failures at once, whereas here they dropped down the ladder quite a few steps at once.

Loosing an engine needs to be covered, as well as loosing generator(s), but loosing ALL GENS at once needn't be covered in planning, just as loosing ALL engines at once obviously needn't be covered.

Small detail, but important nevertheless.

Quoting tdscanuck (Reply 82):
Engine fans don't have anti-ice either


Decending to RAT-altitudes doesn't pose a problem to your RAT durability in relation to icing indeed, but it may very well pose a problem to your airframe nevertheless, especially when you've lost all electrical busses needed to activate the airplane's anti-ice systems, hence it being so important to have an inventary of just what systems were down following the failure: the FCOM doesn't provide that, however and so far, nobody has been able to come up with it.

Quoting tdscanuck (Reply 82):
And also completely covered by existing design. If it weren't, no ETOPS twin, including the A330 and 777, would be certifiable

The case at hand here does not allow for continuation of the flight under any rule, ETOPS or not.

A diversion should be started asap, but when over water, there may not be another option but to continue to the destination, hence it being interesting to know under which conditions this could have been concluded successfully still.

The question here thus becomes: how likely is it the plane would have arrived safely in case there was no other option but to continue to destination? I can come up with several real world scenario's which would make the crew of ANY plane currently flying sweat quite a bit, so Boeing leisurely pretending their 787 could perfectly have landed if the same failure were to have happened at any point during any typical mission profile is utterly ridiculous to me, and so it taking too much confidence from that statement really.

Quoting tdscanuck (Reply 82):
You're also making another tacit assumption...that the plane was *stuck* on RAT power. Given the altitude of the event on final approach, they were obviously going to continue to landing. Although Boeing has been very mum on this topic, we have no concrete evidence for what state the airplane would be in if the event happened at cruise and the flight crew had time to process all the messages. From 600' AGL to landing isn't enough time for most avionics systems to fully restart, or an APU start.

Well, now we're back at square one (see part 1 of this thread): I believe it was Stitch who was quick at assuming the APU could have been started, to which somebody else replied that it may not have been such a great idea to try bringing those GENs online, given the AC network was clearly having serious internal faults and risked inducing further faults, potentially even up to the shedding of the RAT, which is a very valid statement IMHO.

As you say, we don't know and in fact the situation of multiple AC BUS failures isn't covered in the FCOM in any way, so the whole idea that this is just something easily reversible is not demonstrated, in fact it was demonstrated to the contrary even, hence it being a major problem and the test fleet grounded.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Zeke
Posted 2010-12-07 07:41:13 and read 17238 times.

Quoting rottenray (Reply 83):
ONE logical conclusion would be that the crew would have had 2 hours to work the issue.

The industry consensus on cabin/electrical fire is that around 15-20 minutes is available. That has come from events like Swissair 1111, Saudi Arabian 163, UPS 1307, UPS 6, South African 295.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 07:59:41 and read 17171 times.

Not to mention that they wouldn't have much guidance to follow, since basically NOTHING is published on multiple AC bus failures in QRH or FCOM, but hey maybe they could have descended into the aft E&E bay to fight the fire and rerack the faulty hardware, right, like in some Hollywood movies?

Reality is a bit different and less adventurous on a modern flight deck however, especially when staring at a lot of black screens in front of you while listening to the snoring noise of the RAT below your plane....

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Zeke
Posted 2010-12-07 08:07:07 and read 17167 times.

Quoting slz396 (Reply 87):
Not to mention that they wouldn't have much guidance to follow, since basically NOTHING is published on multiple AC bus failures in QRH or FCOM

I disagree, a degraded level of instruments and radios is available off the the 28 VDC bus, which has the main battery and RAT as a supply. Flight controls have their own generators (2 on the left engine, and one on the right) independent of the 235VAC bus.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-07 08:11:24 and read 17152 times.

I ment procedural guidance to work the issue, not instrumental guidance of course, but I agree I wasn't clear on that.

You see, I am beginning to sound just like Boeing: I must definitely take my pills more frequently! 

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rottenray
Posted 2010-12-07 11:00:49 and read 16942 times.

Quoting Zeke (Reply 86):
Quoting rottenray (Reply 83):
ONE logical conclusion would be that the crew would have had 2 hours to work the issue.

The industry consensus on cabin/electrical fire is that around 15-20 minutes is available. That has come from events like Swissair 1111, Saudi Arabian 163, UPS 1307, UPS 6, South African 295.


Yes, which is exactly why the crew put the plane on the ground as quickly as possible.

Beyond that you've made an apples to elephants comparison. This fire self-extinguished, hence if THE EVENTS WE'RE DISCUSSING HAD HAPPENED JUST AS THEY DID EXCEPT FOR BEING ~ 2 hours away from the nearest airfield, the crew would have had ~ 2 hours to work on it.

This thread has truly become the epitome of arguing semantics, selective quoting, and posting for no reason other than the poster seeing his own posts!



But, cheers anyway!

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-07 11:17:40 and read 16910 times.

Quoting rottenray (Reply 90):
This fire self-extinguished, hence if THE EVENTS WE'RE DISCUSSING HAD HAPPENED JUST AS THEY DID EXCEPT FOR BEING ~ 2 hours away from the nearest airfield, the crew would have had ~ 2 hours to work on it.

Not at all, the crew had no idea of what exactly was happening at the time. You do not second guess any fire warning or smoke/fumes.

No pilot that I know would stay in cruise for 2 hours with an unresolved fire warning. The exact cause still is not known weeks later, let alone within 2 hours.

Smoke has killed numerous passengers in the past, even without the presence of fire in the cabin. The crew do not have 2 hours of O2 to protect them either.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ER757
Posted 2010-12-07 11:42:24 and read 16832 times.

Quoting zeke (Reply 91):
No pilot that I know would stay in cruise for 2 hours with an unresolved fire warning.

If you're two hours from the nearest land, do you ditch, or try to continue for those two hours? I would imagine it depends greatly on the severity of the fire but will defer to your expertise as you certainly would know much more than I.
I'm glad we have pilots as members, helps cut through all the conjecture and guessing and allows us to really learn a thing or two. Thanks in advance for your input

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: bikerthai
Posted 2010-12-07 11:54:54 and read 16809 times.

Let's decouple the two question and see if we can get an agreement.

Quoting zeke (Reply 91):
No pilot that I know would stay in cruise for 2 hours with an unresolved fire warning.
Quoting ER757 (Reply 92):

If you're two hours from the nearest land, do you ditch, or try to continue for those two hours?

Would the pilot then drop down to a reasonable altitude if the plane is 2 hrs away from the airport?
You are trading altitude (which would be beneficial if you need to convert it to distance) for safety, in case you have do ditch sooner than desired?

What is the pilot's consensus on this scenario?

Thai

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-07 12:12:07 and read 16785 times.

Quoting ER757 (Reply 92):

It would depend on a number of factors, the two schools of thought are to either to descend down so if the fire/smoke/fumes get worse one is closer for a ditching, another is to go to around FL280 where TAS would be best getting you closer to the airport quicker, however still 5 minutes vertically away from the surface.

At the same time protecting yourself with oxygen and smoke masks, while trying to break the heat/air/fuel fire triangle.

Not that many places where one is that far from some sort of a runway, one would consider a planned emergency landing at an airport that is too small for the type over a ditching. However an extra 10 minutes of smoke could kill everyone.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ER757
Posted 2010-12-07 12:19:00 and read 16726 times.

Quoting zeke (Reply 95):

Thanks for the quick reply - here's hoping you never have to face this choice!!

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: b78710
Posted 2010-12-07 12:22:44 and read 16711 times.

Quoting packsonflight (Reply 70):
(standby instruments are powered from hot battery bus)

I doubt it, Battery bus or standby bus maybe, but not the hot battery bus.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-07 12:54:15 and read 16643 times.

Quoting slz396 (Reply 78):
so what is the problem then for you to ask me why I bother posting here???

Because I am curious about your motives. At no point did I say you were not entitled to your opinions, in fact I said the opposite.

Are you hoping that Boeing reads this thread and decides to come clean with what you consider to be the truth? Do you give any possibility that your assumptions are wrong?

Quoting slz396 (Reply 78):
Several posters have come up with perfectly plausible real world situations any long haul plane can encounter on a day-to-day mission, situations which are clearly not fitting very well that said typical mission profile the 787 was allegedly still perfectly capable of even after the electrical fire and subsequent failures, although I'd say all of those situations are fairly typical indeed, don't you agree?

But do these situations apply to this 787 flight? It is easy to take problems and make hypothetical assumptions as to what could have happened. I can do that quite easily and plausibly for any accident or incident that has ever happened. In fact, I can do that for flights where nothing has happened. That some people believe them doesn't mean they are fact.

Plausible doesn't mean true.


Quoting slz396 (Reply 78):

All those people who have serious questions and even operational problems with the reassuring comments Boeing have made with regard to the electrical fire and allt that has followed, should not just shut up while letting any misunderstandings or remaining ambiguities in place....

They have the right to highlight their concerns and ask others for their opinion, including through public forums, even if that puts into question the reassuring official comments from Boeing itself.

I agree that anybody can post any theory or supposition or proposal or idea or guess that they wish. That doesn't make it the truth. Everybody is free to disagree with anything they wish, as I am free to disagree with you.

I prefer more than theories to believe someone is lying. I need verifiable proof of some kind. Without proof, theory becomes baseless accusation.

Quoting slz396 (Reply 79):
Besides, credibility is gained by making valid points,

Actually, credibility is gained by having ones points proven correct. Just making points which are theoretically possible only increases ones credibility as a theory proposer. Until data and facts prove or disprove a theory, it really is little more than a guess.

[Edited 2010-12-07 13:34:33]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ADent
Posted 2010-12-07 15:29:53 and read 16392 times.

With loss of pressurization you have to drop to low altitudes or kill the folks in back when their oxygen masks run out. On the 787 total AC power loss means loss of pressurization. Or do post 94/95 talk about another scenario with fire warnings but no loss of power ?



Another RAT only flight is very bad, esp on 787 question: How long before it gets very cold in the cabin? What is the OAT at 10K feet? I imagine it would be colder on a trans-polar flight (but more landing options) than LAX-HNL.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-07 21:27:04 and read 16106 times.

Quoting Zeke (Reply 84):
What do you mean by "primary instruments", I have previously listed the DUs (as well as other systems) available with the RAT, the FO outer and inner DUs are blank.

I meant the L & R AHRU/IRU/INR and flight controls (which has more than L & R)...in other words, all your attitude/airspeed/navigation/autoflight capabilities are still present. The FO's displays are blank so he can't pull up some of that data in front of him, but the systems are functioning and available to the pilot-flying.

Quoting Zeke (Reply 84):
The FCOM does not talk about L & R primary instruments when powered by the RAT, just the inner and outer DU, and the lower DU. Information can be projected onto those DUs, including the PFD representation. The days have long gone when a single DU is restricted to displaying one item.

The FCOM provides the list of what's running, which includes the full instrumentation suite...it's the FO displays that are down, not the computers that provide the data and control functions. You're absolutely right that you can move data between physical displays, so the flight crew has access to everything, they just have less screen real-estate to work with.

Quoting Zeke (Reply 84):
Quoting tdscanuck (Reply 65):
The primary flight display is a very concrete, very definite, straight-from-the-FCOM term for a specific flight deck display that is instantly clear to any pilot familiar with modern glass cockpit design. In the case of the 787, you have two PFD's (L & R), one EICAS, and 5 MFD's.

Not when the RAT is deployed.

Sorry, wasn't clear there. I was talking about the normal configuration in response to confusion about what "primary flight display" meant. On RAT, you'd have one PDF, one EICAS, and 3 MFD's.

Quoting Zeke (Reply 84):
The aircraft was in approach configuration when he RAT deployed, it was not able to go into the normal landing or cruise configuration. The aircraft was not in a configuration that would allow it to fly that far at all due to he increased fuel consumption.

This is the part where a crucial unstated assumptions lies, and there isn't enough data to tell which way it actually went...if the plane was in the process of recovering, as several have supposed, the simplest explanation is that they would have recovered some level of primary power (at least alternate flap/slat, for example). Therefore, they would have been able to reconfigure once the system stabilized.

I agree that, *if* the system was stuck on RAT only, they'd be stuck in that slat/flap configuration and diversion range would be severely hampered.

That does put the Boeing statement in a new light though...it's a clear statement...either they were recovering to a point where they could have cleaned up (gear up, slats/flaps retracted) or they're flat out lying. Not a lot of ambiguity either way.

Quoting Zeke (Reply 84):
The Boeing statement of Nov 16, "The airplane concluded the event in a configuration that could have been sustained for the time required to return to an airport suitable for landing from any point in a typical 787 mission profile" is very misleading to be generous.

It's misleading *if* the plane was stuck on RAT power. If the systems were still reconfiguring and/or the APU was startable, the statement is totally valid.

Quoting Zeke (Reply 84):
Also as far as I am aware, no fire protection is available in the area the fire occurred.

Correct...EE bays have fire detection but not fire suppression. They do have fire protection in the sense of not containing flammable material and being capable of being electrically isolated. The fire did self-extinguish of its own accord, according to Boeing, which is what should happen.

Quoting slz396 (Reply 85):
Natural icing tests are NOT centered on a plane with its RAT down and take into account moderate icing conditions only.

Why anti-ice is down isn't relevant to icing testing...what's important is that you've lost anti-ice. In your worst-case scenario, you're talking about having to divert into a situation where you can't find any weather between 0-10000' that is better than moderate icing, *for 6 continuous hours*. I'm not sure if such a weather system even can exist but, even if it can, if our position is just that "there's weather out there that could kill this plane", that's always true for any airplane.

Quoting slz396 (Reply 85):
Quoting tdscanuck (Reply 82):
*All* of the above is included in the flight planning.

Actually, only with reference to a one engine out situation, not to this very exceptional electrical situation.

I need a dispatcher to weigh in here, but I'm not sure how it's possible to not include loss of pressurization in your flight planning. This "very exceptional electrical situation" left the plane fully controllable and flyable, with two operating engines, which is considerably better than worst-case flight planning assumes.

Quoting slz396 (Reply 85):
Loosing an engine needs to be covered, as well as loosing generator(s), but loosing ALL GENS at once needn't be covered in planning, just as loosing ALL engines at once obviously needn't be covered.

For starters, they didn't lose all gen's. Two weren't running (APU) and may or may not have been available given more than ~60 seconds to landing, and four were still running (3 flight control, one RAT). I agree that planning for all generator loss is pointless. The relevant parts here, for flight planning, is loss of pressurization and potentially loss of ability to clean up the airframe. The latter isn't covered by flight planning that I'm aware of...I believe that the former is, but I defer to a dispatcher or line pilot with adequate familiarity.

Quoting slz396 (Reply 85):
Decending to RAT-altitudes doesn't pose a problem to your RAT durability in relation to icing indeed, but it may very well pose a problem to your airframe nevertheless, especially when you've lost all electrical busses needed to activate the airplane's anti-ice systems, hence it being so important to have an inventary of just what systems were down following the failure: the FCOM doesn't provide that, however and so far, nobody has been able to come up with it.

The FCOM can't possibly list all possible combinations of systems go down for any particular failure...that's what EICAS is for. And, given that Boeing said the flight crew had all information necessary to fly safely, EICAS was working.

Quoting slz396 (Reply 85):
The case at hand here does not allow for continuation of the flight under any rule, ETOPS or not.

Please explain...the final state we know about was an aircraft on RAT power (unlimited altitude & duration per the FCOM), safely flyable with all necessary instruments for IMC, two engines running. Anti-ice lost, pressurization lost. If a flight in that state can't be continued, then there are a lot of airplanes running around out there that shouldn't be certified.

Quoting slz396 (Reply 85):
A diversion should be started asap, but when over water, there may not be another option but to continue to the destination, hence it being interesting to know under which conditions this could have been concluded successfully still.

The simplest one is if the APU was available...at that point, you recover primary AC and life is fine. Obviously, we don't know if that was the case or not, but we also don't have any evidence that it wasn't (the P150 panel hasn't come up in any discussions I've seen).

Quoting slz396 (Reply 85):
The question here thus becomes: how likely is it the plane would have arrived safely in case there was no other option but to continue to destination?

I agree that's the crucial question. And I don't see what about the configuration, if this had happened at cruise some hours from the destination, would have precluded continued flight to the destination.

Quoting slz396 (Reply 85):
I can come up with several real world scenario's which would make the crew of ANY plane currently flying sweat quite a bit, so Boeing leisurely pretending their 787 could perfectly have landed if the same failure were to have happened at any point during any typical mission profile is utterly ridiculous to me

I'm not sure why you think their statement was "leisurely"...that was probably one of the most heavily researched press released by a large company in recent memory. And they didn't say "perfectly", they said "safely"...that's a *huge* difference. So far, I see no technical reason from the available information that would render continued safe flight "ridiculous."

Quoting Zeke (Reply 86):
The industry consensus on cabin/electrical fire is that around 15-20 minutes is available. That has come from events like Swissair 1111, Saudi Arabian 163, UPS 1307, UPS 6, South African 295.

I think that's a slightly different case, in that this was a very short duration fire that self-extinguished. The 15-20 minute rule of thumb is, I believe, for a growing fire.

Quoting slz396 (Reply 87):
Not to mention that they wouldn't have much guidance to follow, since basically NOTHING is published on multiple AC bus failures in QRH or FCOM

Actually, the QRH includes complete procedures for every failure involved in this event. The 787 also has electronic checklists, which put (and aggregate) all the required checklist for all failed systems right to the flight crew.

Quoting slz396 (Reply 87):
They maybe they could have descended into the aft E&E bay to fight the fire and rerack the faulty hardware, right, like in some Hollywood movies?

Taking tongue out of cheek for a second, why would you go into the EE bay to fight a fire that had already gone out?

Quoting zeke (Reply 91):
Not at all, the crew had no idea of what exactly was happening at the time. You do not second guess any fire warning or smoke/fumes.

No pilot that I know would stay in cruise for 2 hours with an unresolved fire warning. The exact cause still is not known weeks later, let alone within 2 hours.

The cause and the effect are two different things...I think in most major events, the flight crew doesn't know the exact cause. They know the effects though...in this case, you've got fire indications and electrical problem (plus, probably, messages from all the downstream systems that died). Assuming they weren't on short final and had time to react, the fire self-extinguishes and then you're still going to land as soon as possible, but you're going to be burning down your systems non-normal checklists as you go.

Quoting zeke (Reply 91):
Smoke has killed numerous passengers in the past, even without the presence of fire in the cabin. The crew do not have 2 hours of O2 to protect them either.

Agreed, but this event only lasted 1-2 minutes and self-extinguished. I don't see why 2 hours of O2 would have been required.

Quoting ADent (Reply 98):

With loss of pressurization you have to drop to low altitudes or kill the folks in back when their oxygen masks run out. On the 787 total AC power loss means loss of pressurization. Or do post 94/95 talk about another scenario with fire warnings but no loss of power ?

Post 94/95 are talking about a scenario of in-flight fire without loss of pressurization.

Quoting ADent (Reply 98):
Another RAT only flight is very bad, esp on 787 question: How long before it gets very cold in the cabin?

Depends on the number of people. Typical widebodies start to cool off in about 30-60 minutes.

Quoting ADent (Reply 98):
What is the OAT at 10K feet?

About -5C for a standard atmosphere, but you're way down in the weather so that can vary wildly...anywhere from -50C to +25C, I suspect.

Tom.

Quoting ADent (Reply 98):
I imagine it would be colder on a trans-polar flight (but more landing options) than LAX-HNL.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-07 23:47:59 and read 16000 times.

Quoting tdscanuck (Reply 99):
This is the part where a crucial unstated assumptions lies, and there isn't enough data to tell which way it actually went...if the plane was in the process of recovering, as several have supposed, the simplest explanation is that they would have recovered some level of primary power (at least alternate flap/slat, for example). Therefore, they would have been able to reconfigure once the system stabilized.

Correct, the information is not published. I can only go by what happens on other types, and that is, when the RAT is deployed no reversion is possible. The RAT isolates the essential systems from the rest of the electrical network, no switching is allowed in case of switching or bus fault.

This sort of binary one way option is also on other systems, e.g. fire handle activation. Once the RAT is deployed, it cannot be stowed in flight.

Quoting tdscanuck (Reply 99):

It's misleading *if* the plane was stuck on RAT power. If the systems were still reconfiguring and/or the APU was startable, the statement is totally valid.

The APU will only power a bus that is not powered by an engine driven generator. From what we know the engine driven generators were all working, the fault was the actual bus. The APU would provide no assistance, as the APU cannot power the 28 VDC bus directly, it goes via a 235 VAC bus.

Quoting tdscanuck (Reply 99):
The fire did self-extinguish of its own accord, according to Boeing, which is what should happen.

The crew had no information as to where the fire was, or if it had self extinguished. The smoke detectors detect smoke, or smoke like particles, as they are airborne particles, they can come from a different source, e.g. cabin air or the cargo hold.

Quoting tdscanuck (Reply 99):

I need a dispatcher to weigh in here, but I'm not sure how it's possible to not include loss of pressurization in your flight planning. This "very exceptional electrical situation" left the plane fully controllable and flyable, with two operating engines, which is considerably better than worst-case flight planning assumes.

The 3 scenarios normally planned are :
1) One engine out, pressurised (cruise on a twin would be around FL250)
2) One engine out, depressurised (cruise at FL100)
3) All engines depressurised (cruise at FL100)

Option 3 normally gives the highest fuel burn, the vertical profile is an emergency descent to FL100/MEA the cruise on two engines which has a higher SGR than the OEI case at the same level.

Quoting tdscanuck (Reply 99):

I think that's a slightly different case, in that this was a very short duration fire that self-extinguished. The 15-20 minute rule of thumb is, I believe, for a growing fire.

We only now where the fire was, and have an idea of the duration, no indications would be available to the crew to show the fire was extinguished, and it takes smoke a long time to dissipate from such an enclosed environment. We also do not know if further problems would not happened, as the “fuel” for the fire was removed when the engines were turned off.

Quoting tdscanuck (Reply 99):
Agreed, but this event only lasted 1-2 minutes and self-extinguished. I don't see why 2 hours of O2 would have been required.

Most safety experts are less concerned about the actual fire, and more concerned about the smoke, that is what people are saying got UPS 6 in the end. That is why the checklists, even on the 787 state is smoke or fumes become the greatest threat, their removal is the highest priority, do the smoke or fumes removal checklist.

Passenger oxygen is not such a good idea for cabin or IFE fires, it is just providing more oxygen to the fire, and the passenger masks do not seal, they are providing supplemental oxygen only. Passengers would be better served with a filter of some form (like a wet towel) and try to stay as low as possible out of the layer of smoke.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-08 00:41:35 and read 15946 times.

Quoting tdscanuck (Reply 99):
For starters, they didn't lose all gen's. Two weren't running (APU) and may or may not have been available given more than ~60 seconds to landing, and four were still running (3 flight control, one RAT).

Those APU GENs could not be brought online (not even if they had 2 hours left) and those 3 flight control GENs are just what that say they are, secondary GENs for flight control only: they are not feeding into the faulty electrical network in any way nor can they be made to do so by the crew, so yes indeed, the faulty electrical network did lose all of its GENs, hence the RAT deploying.

There's no disputing the obvious really, but still you do so purely for the sake of being able to point out how many more GENs were operating, albeit completely irrelevant to this analysis. It's like saying there were more than 50 batteries available: the plane's own batteries, those reserved for APU starting and then 46 batteries used in the labtops of the engineers.
  

Quoting tdscanuck (Reply 99):
if the plane was in the process of recovering, as several have supposed, the simplest explanation is that they would have recovered some level of primary power.

Those several who have supposed that it was or could, did they do that on the basis of their best hopes and whishes only, or on their system knowledge?

As has been said unambiguously several times already, the recovery from a RAT down situation on any plane currently equiped with one is not possible and it isn't for some very elementary reasons, inherent to AC networks.

Since you seem not to subscribe to this, I suppose you have clear evidence which says the 787 is the first plane ever to be able to do so, nevertheless?

Otherwise we must assume the 787 to be subject to the very same laws of electricity and physics on this issue and thus the idea the APU GENs could have been brought online to be a stillborn concept, hence come to the conclusion that there was no magical recovery possible from the dire situation indeed.

Quoting tdscanuck (Reply 99):
It's misleading *if* the plane was stuck on RAT power. If the systems were still reconfiguring and/or the APU was startable, the statement is totally valid.

Given the above, I am sure you can see just why so many people with a good understanding of aviation electricity do have quite some problems with the all too casual Boeing statement on the electrical mishap their 787 did experience in flight, luckily while being on short final.

Quoting zeke (Reply 100):
I can only go by what happens on other types, and that is, when the RAT is deployed no reversion is possible. The RAT isolates the essential systems from the rest of the electrical network, no switching is allowed in case of switching or bus fault

Indeed, and that's farly logical too.

I'd be very interesting in learning how one can connect 2 (or even 3) AC sources (the RAT and the 2 APU GENS) straight onto the same bus, without causing massive electrical interferences and a war of currents within that network?

Reality dictates to say you can't, which is why it is never done on any plane flying today and why AC busses are always kept isolated from each other, and only interconnected if a GEN has failed and a bus was unpowered, contrary to DC networks which can easily be connected together. It really is a key difference between AC and DC networks: a single DC bus can be fed by several sources at the same time, an AC bus can't, or is the 787 magically different on this? Care to provide a source then, in case it is?

IMHO, theoretically the only way to get the APU GEN online and avoid the above war of currents, is through first shedding the RAT, but I'd love to see where it says in the 787 FCOM that you should do that when you're down to RAT power????

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Klaus
Posted 2010-12-08 00:53:26 and read 16052 times.

Quoting slz396 (Reply 101):
contrary to DC networks which can easily be connected together.

The connecting is always the easy part – it's sorting out the resulting mess that sucks!   

Even with DC it's quite a bit less trivial than one might think at first glance, particularly when the power sources are voltage-regulated (or even just -limited).

Quoting slz396 (Reply 101):
It really is a key difference between AC and DC networks: a single DC bus can be fed by several sources at the same time, an AC bus can't, or is the 787 magically different on this?

Of course it's possible with AC as well – main grid power stations have been doing that for decades. I would just expect it will not be practical on a plane with its specific circumstances.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: bikerthai
Posted 2010-12-08 07:03:47 and read 15721 times.

As the current discussion is touching on the subject of smoke caused by the fire. My question is as follows:

Typically lower lobe smoke is isolated from main deck by various physical methods and a positive airflow from the main deck to the lower lobe.

Was this the case for the test aircraft?

bikerthai

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Gordomatic
Posted 2010-12-08 07:43:15 and read 15624 times.

Quoting bikerthai (Reply 103):
Was this the case for the test aircraft?

No, due to the fact ZA002 does not have an interior.

Quoting tdscanuck (Reply 82):

Commercial aircraft are certified for smoke penetration testing. Part of smoke containment on any aircraft are the interior panels...which ZA002 doesn't have. There's a reason that Flightbloggger's "better know a Dreamliner" series put the smoke testing on ZA003, the plane that actually does have an interior. Smoke penetration *can't* be an issue on the delivered configuration, or you wouldn't be able to deliver it.


Reply 236 from part 1 of this thread:
"ZA002 doesn't have an interior. The sidewalls and full ECS ducting are an integral part of the smoke containment on any aircraft. There is no reason to think that the cabin on ZA001, ZA002, ZA004, ZA005, or ZA006 *wouldn't* fill with smoke. ZA003 is the only one with an interior."

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: bikerthai
Posted 2010-12-08 07:56:43 and read 15548 times.

Quoting Gordomatic (Reply 104):
ZA003 is the only one with an interior."

Yup, I think I remember the quote about the full interiors. Doesn't mean that there was not some other method to control smoke.

Also I think ZA003 only had a partial interior to verify air flow. Did it also have full sidewalls?

bikerthai

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Gordomatic
Posted 2010-12-08 09:10:35 and read 15473 times.

Quoting bikerthai (Reply 105):
Also I think ZA003 only had a partial interior to verify air flow. Did it also have full sidewalls?

Here are some pictures of ZA0003's interior.


View Large View Medium
Click here for bigger photo!

Photo © Steve Brimley
View Large View Medium
Click here for bigger photo!

Photo © Steve Brimley


View Large View Medium
Click here for bigger photo!

Photo © Steve Brimley
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Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kanban
Posted 2010-12-08 09:20:25 and read 15394 times.

With all the gloom and doom hand wringing about what could have happened but didn't... have any of these posters actually been on an a/p that had a "fire" in the electronics bay knocking out all electrical?... Well I have, and we descended rather quickly to the nearest airfield... and like this the 787, when we landed and evacuated (through the normal exits) they discovered that the "fire" had self extinguished... it was actually a short.

There was no passenger screaming, the aircraft crews were calm and professional... the airline dispatched taxi's to take us on to the destination... although the driver of my car was drunk and we made him pull over and one of the passengers drove. life goes on.

My point is preparing for dramatic tragedy is fine, it happens less frequently than do the precipitating circumstances, but there can be a point where unbridled paranoia isn't constructive anymore.. and I think some of the dialog in this thread is reaching that point. For Pete's sake it's a test a/p doing what it's supposed to do... it was under control and landed without incident, and the engineers and tech are looking at how to resolve some unanticipated developments. Plus there is no new information being posted, just rehashes of "what if", and "if I designed an a/p I would have...", "Boeing is hiding the TRUTH...", "It's not that the prelimanry manuals say"...

Lets's give it a break until we know some solid details instead of rushing to righteous conclusions on heresay...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: justloveplanes
Posted 2010-12-08 09:30:42 and read 15364 times.

Quoting Zeke (Reply 84):
"The airplane concluded the event in a configuration that could have been sustained for the time required to return to an airport suitable for landing from any point in a typical 787 mission profile"

This could be either misleading or revealing as it is a statement equally packed with information and ambiguities.

Point 1 is that they used the word "event" rather than the FAA term "incident". This might be important as it can define a broader expanse of time than the FAA defintion of incident. Logic follows:

The airplane "concluded" the event in a "sustainable" condition "suitable" for return AND landing from "any" point in a typical mission profile.

The first keys are *any* mission profile and *sustainable* for return, which for a long range profile (a leading, but not completely firmed up premise of the statement), would mean the flaps were retracted at the conclusion of the event for the reasons discussed above ad nauseum re: maintaining ETOPS range means the flaps were not extended.

Ergo, the event concluded with the flaps at least somewhat retracted, which means shortly after touchdown, the crew got the APU working and pulled in the flaps, or the ground crew, using a technique available to the crew in flight or easily modified to do so, restored bus power. This is why the word event is important. The meaning of incident would preclude the assistance of ground crew I would think.

So in conclusion, unless the "any typical mission profile" excludes a typical ETOPS mission, these flaps were somehow retracted somewhat prior to the conclusion of the event. This is probably the case, there is VERY little daylight in Boeing's claim that would exclude an ETOPS mission, the prime rationale for building the airplane in the first place, as a non-typical mission profile. Don't think Boeings lawyers would even try that one.

So there it is IMHO, flaps were retracted without effecting repairs by crew or ground staff prior to the conclusion of the "event". So P150 or P200 seems was shortly available.

The word suitable is interesting as used for landing and return. It implies a usable but less than optimal configuration for flying or landing. Hmmmmm.......

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-08 09:33:37 and read 15373 times.

Quoting kanban (Reply 107):

It's just not as entertaining if every issue isn't the spark of some wacky conspiracy theory. Boeing's silence can't possibly be because they are not only solving the original problem but doing extra testing to make sure that not only this problem doesn't happen again, they have also eliminated any other problems they previously hadn't thought of.

The real question is how Elvis managed to escape after he dropped his belt buckle in P100...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kanban
Posted 2010-12-08 09:40:13 and read 15359 times.

Quoting JoeCanuck (Reply 109):
The real question is how Elvis managed to escape after he dropped his belt buckle in P100...



he went out the cargo door ala D. B Cooper.... or was disguised as a fireman and nobody noticed

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: rcair1
Posted 2010-12-08 10:28:04 and read 15258 times.

Quoting tdscanuck (Reply 99):
Quoting ADent (Reply 98):
What is the OAT at 10K feet?

About -5C for a standard atmosphere, but you're way down in the weather so that can vary wildly...anywhere from -50C to +25C, I suspect.

I grew up at "9K" and live at "7K" - I can guarantee it varies a lot. Right now at my house, it is 42 F - so above 0C. Winter ya know.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-08 10:38:42 and read 15227 times.

Quoting justloveplanes (Reply 108):
This could be either misleading or revealing as it is a statement equally packed with information and ambiguities.

The more ambiguous the statement from Boeing, the more it opens them up for liability, not less. For example, with no other information any airline could use their typical flight profile as the standard, should this happen in revenue service.

An Air New Zealand typical flight profile is significantly different than an ANA typical flight profile but since Boeing doesn't differentiate the different 'typicals', each can say theirs is the de facto standard for what Boeing considers typical.

This means that any lawyer can credibly say any flight is typical and the plane should be able to make a safe landing given the same circumstances at any point in any flight.

So instead of the vagueness getting Boeing off the hook, it actually has the potential to get them into much more trouble if they are lying...or just wrong.

On the other hand, there hasn't been one shred of evidence contradicting anything Boeing has said, vague or not. Until there is, all we have are conspiracy theories based on little more than guesswork.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: PITingres
Posted 2010-12-08 13:24:50 and read 14971 times.

Quoting JoeCanuck (Reply 112):
The more ambiguous the statement from Boeing, the more it opens them up for liability, not less.

It is beyond belief to think that Boeing Law had nothing to do with the press release. I rather imagine that they have a very good idea of the liability implications of the public statement. If what you're saying is that the public statement was not meant to be ambiguous, I agree.

Quoting JoeCanuck (Reply 112):
This means that any lawyer can credibly say any flight is typical ...

It means no such thing, neither in logic nor in law. An airline's lawyer can argue that that airline's typical flight is a typical 787 mission; but it does not follow that you can take J Random flight mission and pretend that it's somehow typical.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-08 15:33:49 and read 14743 times.

Quoting PITingres (Reply 113):
It means no such thing, neither in logic nor in law. An airline's lawyer can argue that that airline's typical flight is a typical 787 mission; but it does not follow that you can take J Random flight mission and pretend that it's somehow typical.

How many airlines are in the habit of making random flights? Generally, they flight routes repeatedly, which will result in pattern from which one might discern a typical flight on that route.

If Boeing won't define typical, then who? It doesn't specify anything about a typical flight so it would be up to the users to decided. There are many metrics they could use; hours per flight, miles per flight, average length of flight per route, and I'm sure there are many more ways one might interpret typical.

Some airlines will have a greater number of ETOPS flights than others. Typical for one might not be typical for another.

Not that it matters since the 787 has been sold since its inception as a long range airliner, typical will, without doubt, be assumed to be a long range flight, probably ETOPS flight...the flights on which reliability will be the greatest concern.

Quoting PITingres (Reply 113):
It is beyond belief to think that Boeing Law had nothing to do with the press release. I rather imagine that they have a very good idea of the liability implications of the public statement. If what you're saying is that the public statement was not meant to be ambiguous, I agree.

How about you taking a crack at what Boeing meant by 'typical flight profile'.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: kanban
Posted 2010-12-08 16:51:28 and read 14619 times.

Quoting PITingres (Reply 113):
It is beyond belief to think that Boeing Law had nothing to do with the press release.

Boeing legal approves every official release except maybe blog and twitter mesages... that's why sometimes they're not a timely as we would like...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dakota123
Posted 2010-12-08 19:38:12 and read 14443 times.

Quoting slz396 (Reply 101):
It really is a key difference between AC and DC networks: a single DC bus can be fed by several sources at the same time, an AC bus can't

I don't understand the certainty with which you write. AC generators are automatically synchronized to each other and automatically share load in many, many applications including not only the large-scale systems that bring power to your home, but also applications similar in scope such as ships, hospital back-up power supplies, etc. The automatic synchronizers, synch check devices and load-sharing governors are ubiquitous. There is absolutely nothing magical about this; it is old, old tech.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-08 21:22:14 and read 14345 times.

Quoting zeke (Reply 100):
I can only go by what happens on other types, and that is, when the RAT is deployed no reversion is possible. The RAT isolates the essential systems from the rest of the electrical network, no switching is allowed in case of switching or bus fault.

That's the case *for the bus the RAT is powering*. That's usually called the standby bus, although I'm not sure that's ubiquitous terminology. Once the standby bus switches over to RAT power, it's stuck on RAT power on all designs I'm aware of.

However...the standby bus is *not* the one that the generators connect to. Those buses are just dead when on RAT power if no other sources are available. If a source (APU gen, recovered engine gen, etc.) becomes available, it can be reconnected to the AC buses and you get eveything back. The stuff that went over to the standby bus and RAT power stays on the RAT, but everything else goes back to running from the primary AC buses.

Just to be very very clear: if you drop the RAT, shut down all the primary generators, then restart the primary generators, you get all your systems back. Some of them will be running on the RAT, but they'll all be running since everything that was isolated from the RAT will go back to being powered by the primary generators.

The only things that are irreversable are the switch for the RAT-powered equipment to the RAT, the deployment (you can't stow in flight), and hydraulic reconfiguration (in the case of hydraulic RAT's). The electrical power situation of being only on the RAT is absolutely reversible if you get another generator back up and running.

Quoting zeke (Reply 100):
This sort of binary one way option is also on other systems, e.g. fire handle activation. Once the RAT is deployed, it cannot be stowed in flight.

Agreed. But the fact that the RAT is deployed does *not* prevent non-RAT-powered systems from recovering if another generator is brought online.

Quoting zeke (Reply 100):
The APU will only power a bus that is not powered by an engine driven generator. From what we know the engine driven generators were all working, the fault was the actual bus.

Agreed for all modern architectures (some old designs used synchronous generators where you actually could do this). And, although we agree there was a bus fault, the first protection for most power systems is to drop the generator offline (that's why the first step in a failed bus procedure is to cycle the generator). What's not at all clear yet is if the way the power system responded involved other buses, other generators, or some combination.

Quoting zeke (Reply 100):
The APU would provide no assistance, as the APU cannot power the 28 VDC bus directly, it goes via a 235 VAC bus.

Right but, when the RAT drops, standby bus is isolated from primary AC buses. If you get the APU up and running, the primary buses power back up and everything connected to them powers back up *except* the isolated stuff, which keeps running on the RAT. You end up with everything working, but in a split power configuration (roughly similar to what a 737 does at 1500' AGL while doing an autoland).

Quoting zeke (Reply 100):
The crew had no information as to where the fire was, or if it had self extinguished. The smoke detectors detect smoke, or smoke like particles, as they are airborne particles, they can come from a different source, e.g. cabin air or the cargo hold.

The EICAS messages for smoke identify the location. In a case like this, they should have had something like "AFT EE SMOKE." To meet FAR smoke certification, you need to ensure that smoke in one compartment doesn't cause detectors in another compartment to alarm, so the flight crew should have decent confidence that the EICAS message has the location correct.

Quoting zeke (Reply 100):
The 3 scenarios normally planned are :
1) One engine out, pressurised (cruise on a twin would be around FL250)
2) One engine out, depressurised (cruise at FL100)
3) All engines depressurised (cruise at FL100)

Thanks, that's what I though. Which means all the low altitude issues except loss of anti-ice would have been rolled into the original flight planning.

Quoting zeke (Reply 100):
We only now where the fire was, and have an idea of the duration, no indications would be available to the crew to show the fire was extinguished, and it takes smoke a long time to dissipate from such an enclosed environment.

Agreed that it would take time to dissipate, although EE cooling bays have forced air cooling so they dissipate smoke better than the cargo holds do. Once the smoke was cleared, the related smoke message would clear from EICAS to, giving the flight crew some situational awareness.

Quoting zeke (Reply 100):
We also do not know if further problems would not happened, as the “fuel” for the fire was removed when the engines were turned off.

Boeing actually said "when the fault cleared." It's not clear if that was the electrical system finally getting its act together, the failed component finally burning out and self-isolating, or the engines shutting down.

Quoting slz396 (Reply 101):
Those APU GENs could not be brought online (not even if they had 2 hours left)

Why not? I haven't seen anything to suggest there was a problem with the APU, and the APU doesn't connect in via the P100 panel.

Quoting slz396 (Reply 101):
There's no disputing the obvious really, but still you do so purely for the sake of being able to point out how many more GENs were operating, albeit completely irrelevant to this analysis.

I pointed it out because saying "all gens were lost" means, in a full FBW airliner, you're going to die. That's rather relevant to an analysis of how bad this event was.

Quoting slz396 (Reply 101):
Those several who have supposed that it was or could, did they do that on the basis of their best hopes and whishes only, or on their system knowledge?

I can't read the minds of everyone, but I know for at least three it's based on actual system knowledge.

Quoting slz396 (Reply 101):
As has been said unambiguously several times already, the recovery from a RAT down situation on any plane currently equiped with one is not possible and it isn't for some very elementary reasons, inherent to AC networks.

I think this is the fundamental source of our misunderstanding...the RAT does *not* hook to the primary AC buses. When the RAT drops (for electrical reasons, not hydraulic), the standby bus isolates so that all you get is what the standby bus can power, and everything else is left to fend for itself. If a primary generator, like an APU, comes back online the entire rest of the system recovers...the standby bus and downstream systems stay on the RAT. Net effect: everything powers back up.

Quoting slz396 (Reply 101):
Since you seem not to subscribe to this, I suppose you have clear evidence which says the 787 is the first plane ever to be able to do so, nevertheless?

It's not the first plane to be able to do so. I've done it on multiple aircraft, and you are not stuck on standby power once the RAT deploys if you bring a primary generator back online. Dropping the RAT is a normal part of production testing...you see 777's come in to BFI and PAE with their RAT deployed all the time. They're not coming home on standby power alone.

Quoting slz396 (Reply 101):
I am sure you can see just why so many people with a good understanding of aviation electricity do have quite some problems with the all too casual Boeing statement on the electrical mishap their 787 did experience in flight

No, I don't, because the people who have a good understanding of aviation electricity have *not* said that you're stuck on RAT power forever, even if you get a primary generator back.

Quoting slz396 (Reply 101):
I'd be very interesting in learning how one can connect 2 (or even 3) AC sources (the RAT and the 2 APU GENS) straight onto the same bus, without causing massive electrical interferences and a war of currents within that network?

On older designs, like the original 747, you could happily connect multiple AC sources to the same bus because that's how it was designed. On all modern aircraft that I'm aware of, you just do break power transfers and never have two generators on the same bus at the same time. And I'm not aware that anybody has claimed you would.

This is, incidentally, why the true bus architecture is absolutely crucial. If you only had one AC bus, and the RAT was connected directly to that AC bus, you'd be screwed...once you went on the RAT you'd be stuck there. But that's *not* how aircraft electrical systems are designed. There are multiple AC buses, and the RAT doesn't connect straight into any of the primary buses. As a result, the primary buses power back up happily when a primary generators comes online *even if the RAT is down and the standby bus is on the RAT*.

Quoting slz396 (Reply 101):
a single DC bus can be fed by several sources at the same time, an AC bus can't, or is the 787 magically different on this?

An AC bus can (the original 747 does). But the 787, like the 777, 737, 757, and 767, doesn't do this, nor is there any reason for it to do so.

Quoting slz396 (Reply 101):
Care to provide a source then, in case it is?

FCOM, as posted by Zeke.

Quoting slz396 (Reply 101):
IMHO, theoretically the only way to get the APU GEN online and avoid the above war of currents, is through first shedding the RAT, but I'd love to see where it says in the 787 FCOM that you should do that when you're down to RAT power????

No. You're working off a bad assumption that the RAT powers one of the primary AC buses. It doesn't. Look at reply 183 of this thread: 787 Test Flight Evacuated Due To Smoke - Part 2 (by moderators Nov 19 2010 in Civil Aviation)

The RAT feeds the 235VAC/28VDC box (the square two-colour box with the diagonal slash) in the forward end, *not* the primary AC buses that the APU and engine generators feed.

Quoting bikerthai (Reply 105):
Also I think ZA003 only had a partial interior to verify air flow. Did it also have full sidewalls?

Yep, based on the Farnborough photos.

Quoting JoeCanuck (Reply 114):
If Boeing won't define typical, then who? It doesn't specify anything about a typical flight so it would be up to the users to decided.

Boeing *did* define typical, a long time ago. It's prerequisite to doing the design of any modern airliner.

Quoting dakota123 (Reply 116):
AC generators are automatically synchronized to each other and automatically share load in many, many applications including not only the large-scale systems that bring power to your home, but also applications similar in scope such as ships, hospital back-up power supplies, etc.

Although this is absolutely true in general, this architecture is rarely used on aircraft anymore.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-08 23:10:41 and read 14228 times.

Anyhow, it's now been 1 month since the fire and we still have no clear guidance from Boeing as to:


* Cause of fault

* Reason for cascading failures

* Path to resolution

* Path to restoration of flight test flight program

* Program delay / EIS

* Any change to forward loss position


Leeham is running a poll as t when the bad news will be dumped into the news cycle, hot tip is 23/24 December when all the analysts are on their way to their holiday homes.

If Boeing have not figured out the problem / solution in a month then clearly this is not going to be a quick fix.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: 2175301
Posted 2010-12-09 00:08:41 and read 14141 times.

Quoting dakota123 (Reply 116):

Quoting slz396 (Reply 101):
It really is a key difference between AC and DC networks: a single DC bus can be fed by several sources at the same time, an AC bus can't

I don't understand the certainty with which you write. AC generators are automatically synchronized to each other and automatically share load in many, many applications including not only the large-scale systems that bring power to your home, but also applications similar in scope such as ships, hospital back-up power supplies, etc. The automatic synchronizers, synch check devices and load-sharing governors are ubiquitous. There is absolutely nothing magical about this; it is old, old tech.


I have worked in the power generation field for decades. All major power plants are manually synchronized to the grid. Only relatively small (compared to the grid) generators use auto synchronization where the reliability problems of the auto synchronizers will only affect the small generator (if phased wrong it the grid will force the machine to match it - which can result in physical damage to the small generator if its too far out of phase - but not much of a disturbance to the grid). If you sych in a large generating unit (compared to the local area grid) - you may knock other power plants offline (I've scene that happen at plants I've worked at). Within the last 3 years 2 major new power plants have come on line in my state (450 MW IIRC, and 600 MW) and they are also manual synchronized (no auto contorls at all).

In an airplane where the generators are 25% to 50% of the capacity of the system (the grid) - I would not trust auto synchroizing at all.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Caryjack
Posted 2010-12-09 00:14:49 and read 14128 times.

Quoting tdscanuck (Reply 65):
The flight envelope, in the structural context that's relevant to the wing-body fix, is the plot of allowable Nz vs. GW (inside the curve good, outside the curve bad).

According to Google, Nz GW has something to do with New Zeland's hydro power grid.   Where would I find the aeronautical meaning of these terms?
Thanks,   
Cary

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tropical
Posted 2010-12-09 03:21:36 and read 13948 times.

Apologies if this has been reported already.

Boeing officials 'tell Air France 787 first deliveries delayed until July 2011'

http://www.straitstimes.com/Breaking...s/Money/Story/STIStory_612059.html

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-09 04:34:04 and read 13790 times.

Quoting tdscanuck (Reply 117):
Quoting slz396 (Reply 101):
Those APU GENs could not be brought online (not even if they had 2 hours left)

Why not? I haven't seen anything to suggest there was a problem with the APU, and the APU doesn't connect in via the P100 panel.

Regardless the fact whether or not the APU GENs could or could not safely be connected to the network after the plane fell back to RAT power due to the electrical fire, the 787 is dispatchable without APU too (or isn't it?) and in that case the problem solving option we've analysed and discussed here in depth would not have been available to the crew.

So theoretically at least, with all ENG GENs wrongly shed by the system after the fire and the APU dead upon departure, the situation remains exactly as painted above.

[Edited 2010-12-09 04:57:16]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Klaus
Posted 2010-12-09 05:02:21 and read 13732 times.

Quoting 2175301 (Reply 119):
In an airplane where the generators are 25% to 50% of the capacity of the system (the grid) - I would not trust auto synchroizing at all.

Particularly since the newer systems (A380, 787) don't have a constant speed drive any more but are rigidly coupled to the engine RPM. Simplified systems, but at a price.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: okie
Posted 2010-12-09 05:17:18 and read 13727 times.

Quoting dakota123 (Reply 116):
don't understand the certainty with which you write. AC generators are automatically synchronized to each other and automatically share load in many, many applications including not only the large-scale systems that bring power to your home, but also applications similar in scope such as ships, hospital back-up power supplies, etc. The automatic synchronizers, synch check devices and load-sharing governors are ubiquitous. There is absolutely nothing magical about this; it is old, old tech


The 787 has 4 "wild" starter/generators there is no synchronization. The gens are always out of sync. and there is no load share.

Quoting 2175301 (Reply 119):

I have worked in the power generation field for decades. All major power plants are manually synchronized to the grid. Only relatively small (compared to the grid) generators use auto synchronization where the reliability problems of the auto synchronizers will only affect the small generator (if phased wrong it the grid will force the machine to match it - which can result in physical damage to the small generator if its too far out of phase


This has been one of my contentions from the start is that some failure, (software, interlock, welded contacts) put two generators head to head which caused the arc fault at the P100 panel since the starter/generators are unsynchronized.

Okie

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: slz396
Posted 2010-12-09 05:29:47 and read 13706 times.

Quoting okie (Reply 124):
This has been one of my contentions from the start is that some failure, (software, interlock, welded contacts) put two generators head to head which caused the arc fault at the P100 panel since the starter/generators are unsynchronized.

That doesn't match the FOD mantra from Boeing, although indeed, a FOD mishap with the object fully disappearing after the event, is far less damaging from a PR perspective than what you are proposing here.

Given it's not the first time Boeing has put PR before truth, you could have a valid point though, as Boeing's word isn't worth a cent any longer.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Richard28
Posted 2010-12-09 05:59:04 and read 13634 times.

Reports of a delay in 787 deliveries until Q3 2011

http://economictimes.indiatimes.com/...uly-Report/articleshow/7071186.cms

[Edited 2010-12-09 05:59:25]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Klaus
Posted 2010-12-09 06:01:36 and read 13743 times.

Quoting slz396 (Reply 125):
Given it's not the first time Boeing has put PR before truth, you could have a valid point though, as Boeing's word isn't worth a cent any longer.

They would have all their certifications yanked in no time if that was true.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-09 06:08:32 and read 13739 times.

Quoting Caryjack (Reply 120):
According to Google, Nz GW has something to do with New Zeland's hydro power grid.  
Where would I find the aeronautical meaning of these terms?

Sorry...Nz = normal (vertical) acceleration, GW = gross weight.

For any particular gross weight, there is a maximum and minimum vertical acceleration ("g") that the airplane has to be certified to withstand.

Quoting slz396 (Reply 122):
Regardless the fact whether or not the APU GENs could or could not safely be connected to the network after the plane fell back to RAT power due to the electrical fire, the 787 is dispatchable without APU too (or isn't it?

As far as I know, yes, you can dispatch without APU. Otherwise their ability to do an electrical engine start from ground power wouldn't seem very useful.

Quoting slz396 (Reply 122):
and in that case the problem solving option we've analysed and discussed here in depth would not have been available to the crew.

You lost me...do we have some evidence that they actually *did* dispatch with the APU inop in this case? You certainly couldn't dispatch for 330-minute ETOPS with APU inop (since you like references, that would be in the DDG).

Quoting slz396 (Reply 122):
So theoretically at least, with all ENG GENs wrongly shed by the system after the fire and the APU dead upon departure, the situation remains exactly as painted above.

No. If the APU was dead on departure, you wouldn't have the same ETOPS allowables (if you were allowed to do ETOPS at all)...not sure what the exact planning is, but you don't get full ETOPS rating with no APU, so the length of the possible diversion would be considerably shortened.

Also, electrically shedding a generator is a reversible operation. I don't know exactly what happened in this case vis a vis generator shedding, but on all modern aircraft I'm aware of shedding the generator is one of the first things that should happen to protect both the generator and the bus. Then you cycle the generator (this is the first step in the loss of a bus checklist on many aircraft). If it comes back up, great. If the fault is still present it will trip off again (or never come back up), relatively little harm done. There is insufficient data from what Boeing has published to make an absolute determination on this front, but none of the evidence that's come out so far says that they couldn't have brought the engine generators back once the fault cleared. Presumably the bus that actually faulted was good and dead, but if the other buses went offline because of poor fault response, once the fault is gone they should be recoverable (and Boeing did explicitly state that the fault cleared, although we don't know at what point that occurred).

Note that there is also the capability on many designs to *mechanically* disconnect the generator. This is an irreversible operation in flight, but it also isn't normally done by the electrical system. It's a manual operation by the crew that's usually related only to engine and/or generator mechanical failures.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Revelation
Posted 2010-12-09 10:19:53 and read 13421 times.

Quoting tdscanuck (Reply 128):
No. If the APU was dead on departure, you wouldn't have the same ETOPS allowables (if you were allowed to do ETOPS at all)...not sure what the exact planning is, but you don't get full ETOPS rating with no APU, so the length of the possible diversion would be considerably shortened.

Thanks for this and other clarifications. At least there is some benefit for some member's extremely circumspect viewing of public statements: I for one have a much better idea of how modern airliner electrical designs work.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-09 10:23:00 and read 13434 times.

Quoting slz396 (Reply 125):

That doesn't match the FOD mantra from Boeing, although indeed, a FOD mishap with the object fully disappearing after the event, is far less damaging from a PR perspective than what you are proposing here.

Yet, there is not one teeny shred of evidence in public to support this. It seems you are accusing Boeing of lying. Are you? If so, do you have any evidence to support this?

True, without wild, baseless accusations and assumptions A.net might cease to exist but occasionally it would be refreshing to have some theories confirmed with facts.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ER757
Posted 2010-12-09 10:33:56 and read 13418 times.

Quoting tropical (Reply 121):
Boeing officials 'tell Air France 787 first deliveries delayed until July 2011'

Interesting that they told AF since they haven't even ordered the aircraft (unless they are a UFO order already on the books)

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tarheelwings
Posted 2010-12-09 10:51:08 and read 13372 times.

Quoting ER757 (Reply 131):
Interesting that they told AF since they haven't even ordered the aircraft (unless they are a UFO order already on the books)

Assuming of course that this report is true.....one never knows with all the rampant speculation going on. I'll wait for the official Boeing announcement, and yes, it would be nice if they did sooner rather than later but I'm sure Boeing has other constituencies to worry about besides a.net.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-09 11:07:49 and read 13334 times.

Quoting tarheelwings (Reply 132):
I'm sure Boeing has other constituencies to worry about besides a.net.

That's just crazy talk, mister...you take that back...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ER757
Posted 2010-12-09 11:40:53 and read 13232 times.

Quoting tarheelwings (Reply 132):
'm sure Boeing has other constituencies to worry about besides a.net.

Others maybe, but none more important or influential!  

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Bennett123
Posted 2010-12-09 12:04:22 and read 13207 times.

According to Flight International, 07/12/2010 to 13/12/2010.

"Wells Fargo has cut its estimate of Boeing's 2011 787 deliveries to just 12 units, from 53 and its 2012 expectation to 50 units from 75".

IMO this ties in with EIS in Q3 2011.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dakota123
Posted 2010-12-09 14:24:40 and read 12925 times.

Quoting 2175301 (Reply 119):
I have worked in the power generation field for decades. All major power plants are manually synchronized to the grid. Only relatively small (compared to the grid) generators use auto synchronization where the reliability problems of the auto synchronizers will only affect the small generator (if phased wrong it the grid will force the machine to match it - which can result in physical damage to the small generator if its too far out of phase - but not much of a disturbance to the grid). If you sych in a large generating unit (compared to the local area grid) - you may knock other power plants offline (I've scene that happen at plants I've worked at). Within the last 3 years 2 major new power plants have come on line in my state (450 MW IIRC, and 600 MW) and they are also manual synchronized (no auto contorls at all).

In an airplane where the generators are 25% to 50% of the capacity of the system (the grid) - I would not trust auto synchroizing at all.

Getting really far afield, and mods feel free to delete, but likewise, I'm in the generation biz (an engineer by training, developing, permitting, building, and in days passed, operating) and have been in many, many facilities large and small and see auto synch all the time, with no unit size limits. Obviously the synch and other condition matching devices need to be set up correctly, but they are able to set RPM, voltage, phase and desired initial load as reliably as a human. As well, the protection devices installed to *ensure* that the oncoming generator is at the correct line condition are installed, and offer the same protection, whether a synch is performed manually or automatically. Usually a lack of auto-synch is more the beancounters not wanting to spend the money -- I agree with that, actually, since it really isn't necessary as that's what you pay the operators for.

I can understand why break-before-make is employed with modern A/C (although it sure seems to play havoc with United's A3XX entertainment/safety briefing system, what with the screens flipping up and down as house power/APU is switched to engine generators); all I was responding to in any case was the apparent certainty of slz396 that AC busses cannot be tied together...

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-09 21:02:15 and read 12608 times.

Quoting dakota123 (Reply 136):
I can understand why break-before-make is employed with modern A/C (although it sure seems to play havoc with United's A3XX entertainment/safety briefing system, what with the screens flipping up and down as house power/APU is switched to engine generators)

Ancillary equipment often doesn't take the power transfers well...this isn't particularly unique to the the particular aircraft you're talking about. I think the major reason aircraft went to the break-before-make architecture is weight...you can ditch a lot of equipment if you don't care about generator synchronization.

Quoting dakota123 (Reply 136):
all I was responding to in any case was the apparent certainty of slz396 that AC busses cannot be tied together...

Not only can it be done, it has been done on aircraft (and is still done on some aircraft that are flying now)...it's just not done on any new designs.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-09 21:54:13 and read 12573 times.

Quoting tdscanuck (Reply 117):
That's the case *for the bus the RAT is powering*. That's usually called the standby bus, although I'm not sure that's ubiquitous terminology.

The RAT does not power any bus directly, it goes via T/R, that T/R feeds the 28 VDC bus.

Quoting tdscanuck (Reply 117):

However...the standby bus is *not* the one that the generators connect to.

Correct.

Quoting tdscanuck (Reply 117):
Those buses are just dead when on RAT power if no other sources are available.

Correct.

Quoting tdscanuck (Reply 117):
The stuff that went over to the standby bus and RAT power stays on the RAT, but everything else goes back to running from the primary AC buses.

That is not what FCOM says. While the power might be there, the common core is still powered off the RAT, so the control aspect is lost, it is all "by wire", rather than mechanical linkage.

Quoting tdscanuck (Reply 117):

Just to be very very clear: if you drop the RAT, shut down all the primary generators, then restart the primary generators, you get all your systems back. Some of them will be running on the RAT, but they'll all be running since everything that was isolated from the RAT will go back to being powered by the primary generators.

That does not agree with FCOM, it says auto throttle, flaps, slats, stabilizer, thrust reverse, auto speed brake, air-conditioning/pressurization, HUDs, HF radios, SATCOM, external lighting, WIPS, and window heat are inoperative when the RAT is powering the 28 VDC bus.

Quoting tdscanuck (Reply 117):

Agreed. But the fact that the RAT is deployed does *not* prevent non-RAT-powered systems from recovering if another generator is brought online.

What is going to control them ?

Quoting tdscanuck (Reply 117):
The EICAS messages for smoke identify the location. In a case like this, they should have had something like "AFT EE SMOKE." To meet FAR smoke certification, you need to ensure that smoke in one compartment doesn't cause detectors in another compartment to alarm, so the flight crew should have decent confidence that the EICAS message has the location correct.

FCOM actually shows that the EE bays have no smoke detection, it is located upstream and downstream of the bays in the ducts. The EICAS message would be "SMOKE EQUIP CLG AFT". From the EE bays the air is ducted into the cargo bays, the smoke sensor sits between the EE bay and the cargo bay. However as I indicated before, the air-conditioning and pressurization is kicked off when the RAT is deployed, so the smoke would not get vented.

Quoting tdscanuck (Reply 117):
Which means all the low altitude issues except loss of anti-ice would have been rolled into the original flight planning.

We include anti-ice and other buffers in our flight planning. The requirements often ask for planning at Vmo/Mmo but that is planning stage, no one in their right mind is going to fly Vmo/Mmo after an in-flight failure (unless it was truly time critical).

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-09 22:24:54 and read 12550 times.

Quoting zeke (Reply 138):
That is not what FCOM says. While the power might be there, the common core is still powered off the RAT, so the control aspect is lost, it is all "by wire", rather than mechanical linkage.

Power to a system is not the same as what that system can control. Just because the common core system is getting is power from the RAT doesn't mean it can't send commands to other components.

When you first turn the battery on, you get even less stuff powered than you do when on RAT (including the same common core system), yet that's enough to start the APU and bring those generators online. The battery bus, which doesn't shut down when you drop the RAT, is more than capable of bringing generators online since that's what it does every time you do a normal procedure non-EP start.

Quoting zeke (Reply 138):
That does not agree with FCOM, it says auto throttle, flaps, slats, stabilizer, thrust reverse, auto speed brake, air-conditioning/pressurization, HUDs, HF radios, SATCOM, external lighting, WIPS, and window heat are inoperative when the RAT is powering the 28 VDC bus.

That set of components is from the FCOM section for RAT-only power. The actual title is "In-Air RAT Only Mode (Standby Power)". That's not the same power state you'd be in if you dropped the RAT and then brought some or all of the primary AC generators back online (this is nothing unique to the 787, the 777 is the same way).

Quoting zeke (Reply 138):
Quoting tdscanuck (Reply 117):
Agreed. But the fact that the RAT is deployed does *not* prevent non-RAT-powered systems from recovering if another generator is brought online.

What is going to control them ?

Generator switch on the P-5 overhead panel...you can see the switches in the flight deck photos in the database. They still work when on battery power, which is actually a worse power state than being on RAT power.

Quoting zeke (Reply 138):
FCOM actually shows that the EE bays have no smoke detection, it is located upstream and downstream of the bays in the ducts. The EICAS message would be "SMOKE EQUIP CLG AFT". From the EE bays the air is ducted into the cargo bays, the smoke sensor sits between the EE bay and the cargo bay.

I'm not really seeing the distinction here...although the detectors are physically in the exhaust duct from the EE bay, their air source is the EE bay and only the EE bay. So, if they see smoke, it has to come from the related EE bay (hence the location-specific EICAS message). Thanks for posting the correct message text.

An an aside, air from the EE bay doesn't actually go into the cargo bay, it goes around the cargo bay (for heating).

Quoting zeke (Reply 138):
However as I indicated before, the air-conditioning and pressurization is kicked off when the RAT is deployed, so the smoke would not get vented.

Agreed, if you stayed on RAT power. If you could get the APU or engine generators back online, you get air-conditioning and pressurization back.

In case anyone is wondering why I'm so sure that you can get the primary generators back online after you deploy the RAT, it comes from the dual-engine failure checklist (which is the same as a 777 as well)...in the event of dual engine failure, you cycle the fuel switches (to get the engines trying to restart), then drop the RAT, *then* start the APU. That procedure would make no sense, and accomplish nothing, if it weren't possible to bring the APU online after a RAT deployment.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: mdword1959
Posted 2010-12-10 00:38:03 and read 12450 times.

Guy Norris (AWST) has posted some interesting information:

Quote:
...more information is emerging about the specific areas of damage and the precise location of the fire behind the P100 panel. This takes the electrical power generated by the left engine and distributes it to power vital systems. The panel, measuring about 3.5 ft tall, is located about 1 ft below the passenger floor in the afte electronics bay just behind the wing. It contains electrical boxes, including control units, circuit breakers and relays.

Forensic evidence from the fire damage pinpoints one of two contactors in the P100 panel, CK2435505, as the source of the ignition. The contactors are electrical control boxes that relay the power from the generators on the engine and distribute it as needed. They open circuits or close as power needs fluctuate. Contactor CK2435505, on top of the panel, was “melted” according to engineering reports, while the lower contactor CK2421501 suffered "extensive fire and smoke damage to backside."

Fire from the contactor burned a hole between 12 and 15 inches long in the back of the P100 panel, and badly charred the adjacent fuselage insulation blanket material which effectively did its job in preventing burn-through to the interior of the 787’s primary composite fuselage skin structure.
http://www.aviationweek.com/aw/blogs...=blogScript&plckElementId=blogDest

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-10 01:12:21 and read 12410 times.

Quoting tdscanuck (Reply 139):

When you first turn the battery on, you get even less stuff powered than you do when on RAT (including the same common core system), yet that's enough to start the APU and bring those generators online.

Only when the aircraft has positive "on ground" signal, hence the name "on ground battery only" which is different to the "in air battery only". FCOM does not say in the "in air battery only" or "in air RAT only" configurations that the APU start is possible. They are powered via a different source, the APU battery. The APU battery is in the rear of the aircraft, and the main battery is in the front, they are not connected.

Quoting tdscanuck (Reply 139):
That set of components is from the FCOM section for RAT-only power. The actual title is "In-Air RAT Only Mode (Standby Power)".

Exactly, "In-Air". That goes back to what we said before, once the RAT has kicked in, and the aircraft is "in-air", it isolates selected systems, and that normally remains while the aircraft is "in-air".

Quoting tdscanuck (Reply 139):

I'm not really seeing the distinction here...although the detectors are physically in the exhaust duct from the EE bay, their air source is the EE bay and only the EE bay.

And where does the air upstream of the EE come from ? Why have a smoke sensor upstream of the EE bay ?

Quoting tdscanuck (Reply 139):
An an aside, air from the EE bay doesn't actually go into the cargo bay, it goes around the cargo bay (for heating).

FCOM just says "to aft cargo compartment". Where does the cargo compartment get its air from ?

Quoting tdscanuck (Reply 139):
That procedure would make no sense, and accomplish nothing, if it weren't possible to bring the APU online after a RAT deployment.

The reason for the APU use is to assist the engine start. After a dual engine failure and restart/no restart, you are not going to continue to your destination.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Klaus
Posted 2010-12-10 01:24:37 and read 12382 times.

Quoting zeke (Reply 138):
That does not agree with FCOM, it says auto throttle, flaps, slats, stabilizer, thrust reverse, auto speed brake, air-conditioning/pressurization, HUDs, HF radios, SATCOM, external lighting, WIPS, and window heat are inoperative when the RAT is powering the 28 VDC bus.

Does that mean yaw damper and other automatic functions? Or is even stabilizer trim disabled as well?

Quoting mdword1959 (Reply 140):
Forensic evidence from the fire damage pinpoints one of two contactors in the P100 panel, CK2435505, as the source of the ignition.

One of the interesting points would probably be whether the fire resulted from a defect of the contactor component itself or from incorrect operation of the contactor by the control logic (including the control software).

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-10 06:25:18 and read 12179 times.

Quoting zeke (Reply 141):
FCOM does not say in the "in air battery only" or "in air RAT only" configurations that the APU start is possible.

The FCOM doesn't, at least anywhere that I can find. The QRH does though.

Quoting zeke (Reply 141):
They are powered via a different source, the APU battery. The APU battery is in the rear of the aircraft, and the main battery is in the front, they are not connected.

The APU battery provides power to spin the APU starter/generators. The ships battery is what's powering the command & control components (APU start switch, common core, etc.).

Quoting zeke (Reply 141):
That goes back to what we said before, once the RAT has kicked in, and the aircraft is "in-air", it isolates selected systems, and that normally remains while the aircraft is "in-air".

I agree. The isolated systems remain on RAT power in-air. What's not true is that the non-isolated systems (i.e. everything that's not on the RAT) are cut off from all power sources. If you get a primary generator back up, the isolated systems stay isolated (powered by the RAT), the non-isolated systems come back up and get powered by the now-recovered primary power system.

Quoting zeke (Reply 141):
And where does the air upstream of the EE come from ?

Fwd EE comes from the flight deck, I think...and you've got two hypersensitive smoke detectors on the flight deck. Aft EE comes from the cabin, I think, where you also have several (something like ~40 in this case) hypersensitive smoke detectors.

Quoting zeke (Reply 141):
FCOM just says "to aft cargo compartment". Where does the cargo compartment get its air from ?

It doesn't. You don't pump air into cargo bays...otherwise it's nearly impossible to meet the fire suppression requirements.

Quoting zeke (Reply 141):
The reason for the APU use is to assist the engine start. After a dual engine failure and restart/no restart, you are not going to continue to your destination.

The engines are started by starter/generators (no pneumatic start here)...there is no way for the APU to assist the engine start unless the APU generators can power the primary AC buses *and* the AC buses can distribute power.

If the systems really do completely isolate on RAT and the non-isolated systems are dead as long as you're in the air, then there is zero point in starting the APU. The fact that they do start the APU, and do it after dropping the RAT, can only mean that the APU can re-power the primary AC buses after a RAT deployment. I've done this on multiple Boeing aircraft...you are *not* stuck on RAT only power after dropping the RAT if you have functional primary generators.

Quoting Klaus (Reply 142):
Does that mean yaw damper and other automatic functions? Or is even stabilizer trim disabled as well?

"Stabilizer" in that context means horizontal stabilizer...yaw damper should be fine as long as you've got functional flight controls.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Tristarsteve
Posted 2010-12-10 06:42:37 and read 12167 times.

Quoting dakota123 (Reply 136):
I can understand why break-before-make is employed with modern A/C

A lot of modern aircraft have no-break transfer.
The B777 and A330 to name two.
When transferring from ground power to APU., and from APU to Engine generators, the generators are brought in-phase and actually power the bus simultaneously for a split second.
You can see this when you select APU gen on. The On light does not come on straight away. There can be a pause of 2 to 5 secs while the phases are aligned.

Quoting zeke (Reply 141):
FCOM just says "to aft cargo compartment". Where does the cargo compartment get its air from ?

The air is exhausted to the area between the fuselage and the cargo compt lining, same place as air from the cabin goes.
The cargo hold ventilation system, if fitted and switched on, takes its air from the same area, but there is much more cabin air there than avionic air. The cargo hold vent has an inlet valve that would close with a cargo fire warning.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: bikerthai
Posted 2010-12-10 07:31:05 and read 12040 times.

Quoting tdscanuck (Reply 143):
You don't pump air into cargo bays

I thought that the air in the cargo bays comes from the main deck. I was told that there is positive pressure airflow from the head of the passenger to the foot then down to the lower lobe via the side wall vent. Has this changed for the 787?

bikerthai

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Klaus
Posted 2010-12-10 07:47:09 and read 12012 times.

Quoting tdscanuck (Reply 143):
"Stabilizer" in that context means horizontal stabilizer...yaw damper should be fine as long as you've got functional flight controls.

So what's missing is just horizontal stabilizer trim, effectively? The elevators remain online?

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-10 08:03:02 and read 12012 times.

Quoting tdscanuck (Reply 143):
If you get a primary generator back up, the isolated systems stay isolated (powered by the RAT), the non-isolated systems come back up and get powered by the now-recovered primary power system.

As discussed earlier, common core still remains RAT powered (i.e. isolated), and that is what controls those systems.

Quoting tdscanuck (Reply 143):
Fwd EE comes from the flight deck, I think...and you've got two hypersensitive smoke detectors on the flight deck. Aft EE comes from the cabin, I think, where you also have several (something like ~40 in this case) hypersensitive smoke detectors.

So your previous comment, "the detectors are physically in the exhaust duct from the EE bay, their air source is the EE bay and only the EE bay" cannot also be true.

Quoting tdscanuck (Reply 143):
The engines are started by starter/generators (no pneumatic start here)...there is no way for the APU to assist the engine start unless the APU generators can power the primary AC buses *and* the AC buses can distribute power.

My understanding is that the APU can connect directly to the Large Motor Power Distribution System, similar to the way the external power can connect to that system for engine start.

Quoting tdscanuck (Reply 143):
It doesn't. You don't pump air into cargo bays...otherwise it's nearly impossible to meet the fire suppression requirements.

That also seems to differ from FCOM, you may want to look at the Cargo Compartment Air Conditioning System.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: dakota123
Posted 2010-12-10 08:21:28 and read 11953 times.

Quoting zeke (Reply 100):
The 3 scenarios normally planned are :
1) One engine out, pressurised (cruise on a twin would be around FL250)
2) One engine out, depressurised (cruise at FL100)
3) All engines depressurised (cruise at FL100)

Option 3 normally gives the highest fuel burn, the vertical profile is an emergency descent to FL100/MEA the cruise on two engines which has a higher SGR than the OEI case at the same level.

I'm thinking scenarios 2 or 3 could be pretty nerrve-racking depending on the situation. On a percentage basis, how much higher is fuel consumption in cruise at 10K vs a typical cruising altitude? How is this scenario handled via ETOPS rules?

Mike

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-10 08:36:19 and read 11954 times.

Quoting dakota123 (Reply 148):
I'm thinking scenarios 2 or 3 could be pretty nerrve-racking depending on the situation. On a percentage basis, how much higher is fuel consumption in cruise at 10K vs a typical cruising altitude

About double ballpark.

Quoting dakota123 (Reply 148):
How is this scenario handled via ETOPS rules?

The flight planning system looks at these scenarios and finds the worst point for this to happen on the route, it then looks at the fuel required from that point for the diversion. Depending on where this happens, additional fuel known as "mandatory" is uplifted to ensure you have the fuel to the diversion point, plus the fuel needed for the emergency diversion.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: nomadd22
Posted 2010-12-10 10:17:00 and read 11785 times.

Quoting rcair1 (Reply 45):
I stupidly keep coming to this string to see if anything factual appears. Same with the A380 blown engine strings. What a fool am I
Quoting mdword1959 (Reply 140):
Guy Norris (AWST) has posted some interesting information:

Quote:
...more information is emerging about the specific areas of damage and the precise location of the fire behind the P100 panel. This takes the electrical power generated by the left engine and distributes it to power vital systems. The panel, measuring about 3.5 ft tall, is located about 1 ft below the passenger floor in the afte electronics bay just behind the wing. It contains electrical boxes, including control units, circuit breakers and relays.

Forensic evidence from the fire damage pinpoints one of two contactors in the P100 panel, CK2435505, as the source of the ignition. The contactors are electrical control boxes that relay the power from the generators on the engine and distribute it as needed. They open circuits or close as power needs fluctuate. Contactor CK2435505, on top of the panel, was “melted” according to engineering reports, while the lower contactor CK2421501 suffered "extensive fire and smoke damage to backside."

Fire from the contactor burned a hole between 12 and 15 inches long in the back of the P100 panel, and badly charred the adjacent fuselage insulation blanket material which effectively did its job in preventing burn-through to the interior of the 787’s primary composite fuselage skin structure.
http://www.aviationweek.com/aw/blogs...gDest

I've been betting on the fire being caused by high resistance fom a bad connection or contact from the beginning. I don't usually argue with Boeing engineers, but assuming a FOD short without a smoking gun, or smoking washer seemed pretty premature to someone who has repaired many blasted power panels over the decades. Excess current caused by a short should have been instantly detected. Then again, a voltage drop from a high resistance should have been picked up too.
Once again, I wish we could see the specifics of what got recorded by test, or regular instrumentation on the electrical system. Damn Boeings screwed up priorities anyhow.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-10 12:52:01 and read 11630 times.

There was some hope for optimism in the article. It would be good news if they could continue test flights in January.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: RedChili
Posted 2010-12-10 13:19:06 and read 11944 times.

Quoting tdscanuck (Reply 143):
Quoting zeke (Reply 149):

Tdscanuck and Zeke, you've got a lot of very good and interesting posts in this thread. Although I don't understand all the technical stuff, it's great to read both of your takes on this. You're seeing it from two very valid and important viewpoints.

My personal uneducated guess on this whole event: The fire did self extinguish fairly quickly, so in theory it would be possible make a safe return from an ETOPS flight to the nearest airport. However, if this had indeed happened on a real ETOPS flight, with a couple of pilots not really knowing what's going on except that there is a fire and a lot of smoke somewhere, and that they've lost a lot of electricity, and having no idea whether and when the fire may self extinguish, the pilots could very well have chosen to either ditch as soon as possible, or at least made a quick dive to a much lower flight level. The result of a ditch would've been loss of an airframe and probably lives, while a much lower flight level would've meant much higher fuel burn and a risk of ditching later on.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-11 17:38:42 and read 11188 times.

Quoting Tristarsteve (Reply 144):
A lot of modern aircraft have no-break transfer.
The B777 and A330 to name two.

I'm pretty sure they implement the no-break transfer by having the loads spec's to handle the brief interruption, as opposed to actually having two generators on one bus momentarily.

Quoting Tristarsteve (Reply 144):
When transferring from ground power to APU., and from APU to Engine generators, the generators are brought in-phase and actually power the bus simultaneously for a split second.

Is the electrical system actually manipulating the transmission inside the IDG to align the phases? That's the only way I can see them coming in phase, since I don't think the bus power controls have the authority to tell the APU or the engines to change speed.

Quoting bikerthai (Reply 145):
I thought that the air in the cargo bays comes from the main deck. I was told that there is positive pressure airflow from the head of the passenger to the foot then down to the lower lobe via the side wall vent. Has this changed for the 787?

It has not changed for the 787, but you're understanding of how other aircraft do it isn't quite right. The air from the cabin flows into the sidewall vent, as you describe, but then it flows *around* the cargo bay, not into it. The outflow valves vent the space between the cargo hold liners and the fuselage skin. The airflow path is down from the main deck ceiling, out the side wall vents, down between the cargo liners and the skin, then out the outflow valves.

Quoting Klaus (Reply 146):
So what's missing is just horizontal stabilizer trim, effectively? The elevators remain online?

That's what I get from everything that's been posted, yes. As long as hydraulics and flight controls are up (and there's been zero posting/rumour/evidence that they were down), you've got elevators.

Quoting zeke (Reply 147):
As discussed earlier, common core still remains RAT powered (i.e. isolated), and that is what controls those systems.

Agreed, but isolation of the power side has nothing to do with isolation of the command/control/sensor systems. I'm not aware of any aircraft that isolates the non-power side in response to a RAT drop, and I have no idea why you would (there are a lot over very good reasons you wouldn't). It's actually only CCR-L (Common Core Resource-Left) that is on RAT power...CCR-R is offline when on RAT alone. But there's nothing to prevent CCR-L from starting the APU, even when on RAT and/or battery power. If there were something preventing it, two things would happen...1) you couldn't start the APU on a dead airplane and 2) the dual-engine failure checklist wouldn't work. Since the 787 and 777 share the dual-engine failure checklist, I'm pretty sure somebody would have noticed if they don't work by now.

And, since I've done that checklist on multiple Boeing aircraft, I *know* it works as advertised (you can start the APU in-air when on RAT-only power).

Quoting zeke (Reply 147):
Quoting tdscanuck (Reply 143):
Fwd EE comes from the flight deck, I think...and you've got two hypersensitive smoke detectors on the flight deck. Aft EE comes from the cabin, I think, where you also have several (something like ~40 in this case) hypersensitive smoke detectors.

So your previous comment, "the detectors are physically in the exhaust duct from the EE bay, their air source is the EE bay and only the EE bay" cannot also be true.

I'm not really following you. The EE bay supply is either flight deck (fwd) or cabin (aft)...that air flows into the EE bay, then exhausts through ducts with smoke detectors. Any air that goes to the detectors has to have come from the EE bay. It's possible, of course, that you could have smoke in the flight deck or main deck that would then go to the EE bay and be detected but, in that case, the detector is still correct (you've got smoke in the EE bay) *and* you'd know that you had smoke on the main deck/flight deck because that's not the kind of thing that flight crews and passengers fail to notice.

Quoting zeke (Reply 147):
My understanding is that the APU can connect directly to the Large Motor Power Distribution System, similar to the way the external power can connect to that system for engine start.

That's not correct. The large motor power distribution system is the +-270VDC buses (see the Boeing Aero article I linked earlier for more details). None of the generators on the 787 put out 270VDC...the only way any generator anywhere can power the large motor power distribution system is to get at it via one of the AC buses.

Quoting zeke (Reply 147):
Quoting tdscanuck (Reply 143):
It doesn't. You don't pump air into cargo bays...otherwise it's nearly impossible to meet the fire suppression requirements.

That also seems to differ from FCOM, you may want to look at the Cargo Compartment Air Conditioning System.

Good point...the cargo compartment air conditioning system is optional, so I wasn't really thinking about it. If you don't have it fitted, I believe you have no active air supply, just passive conductive heat from the EE bay exhaust air flowing outside the cargo bay liners.

If you do have the optional fwd cargo air conditioning, it takes fwd EE exhaust air, conditions it, sends it to the fwd cargo bay, then exhausts it overboard. In the event of a smoke detection, the cargo air conditioning shuts down so it reverts to basically the same situation as if you didn't have it.

Quoting RedChili (Reply 152):
However, if this had indeed happened on a real ETOPS flight, with a couple of pilots not really knowing what's going on except that there is a fire and a lot of smoke somewhere, and that they've lost a lot of electricity, and having no idea whether and when the fire may self extinguish, the pilots could very well have chosen to either ditch as soon as possible, or at least made a quick dive to a much lower flight level.

I'll defer to zeke et. al. on this one, but if you have a flyable aircraft I don't see any reason you'd want to ditch. With loss of most power, you've lost pressurization anyway (on a 787) so you'd have descended regardless of the fire state.

Quoting RedChili (Reply 152):
The result of a ditch would've been loss of an airframe and probably lives, while a much lower flight level would've meant much higher fuel burn and a risk of ditching later on.

But the high fuel burn due to flying low is already in the flight planning...you've got enough gas to reach your diversion airport even flying low. As long as the plane is under control and flyable, ditching seems like an unacceptably risky option.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Drewski2112
Posted 2010-12-11 19:33:33 and read 11107 times.

Any news on when any of the six 787's will return to the sky? Not including the ferry flights that airplane one and two took, it's been about a month since a 787 test flight has been flown. I know they're "working through the bugs," but the 787 flight test programme was a seven day a week operation a few months back, and now, nothing (flying, that is).

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-11 21:15:29 and read 11039 times.

Quoting Drewski2112 (Reply 155):
Any news on when any of the six 787's will return to the sky?

Nope.

Quoting Drewski2112 (Reply 155):
Not including the ferry flights that airplane one and two took, it's been about a month since a 787 test flight has been flown.

Planes three and four ferried as well, but that's beside the point. Nobody has flown a test flight since the initial event on ZA002 more than a month ago.

Quoting Drewski2112 (Reply 155):
I know they're "working through the bugs," but the 787 flight test programme was a seven day a week operation a few months back, and now, nothing (flying, that is).

They had a major whoopsie with the FAA on board...they're not going to let anybody back up until they show the FAA that what happened to ZA002 won't happen to any of the others. Based on Boeing's press release that software and hardware changes are coming, that means nobody goes back up until the hardware is changed, and the software is written/tested/installed.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: JoeCanuck
Posted 2010-12-11 22:34:03 and read 10976 times.

Quoting tdscanuck (Reply 156):
They had a major whoopsie with the FAA on board...they're not going to let anybody back up until they show the FAA that what happened to ZA002 won't happen to any of the others.

That was good for a chuckle. Kudos on a fine bit of diplomacy.

I doubt Boeing will issue any EIS deadline until they are darned sure, (at least as sure as they can be), that this will be the last delay...no matter how long it takes. Extending this delay, though bad, is not nearly as bad as another delay after this.

I have no doubts that another delay would result in major cancellations.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: packsonflight
Posted 2010-12-12 02:55:05 and read 10805 times.

Quoting JoeCanuck (Reply 157):
I doubt Boeing will issue any EIS deadline until they are darned sure, (at least as sure as they can be), that this will be the last delay...no matter how long it takes. Extending this delay, though bad, is not nearly as bad as another delay after this.



I think that Boeing sticks to the 6 months interval delay tactics, to limit the impact on stock prices.

Then there is the potential problem with production ramp-up. The 787 outsold the original production plan and I believe that the partners have a problem tooling up for much higher production rate than they originally agreed upon. It must be hard to finance a program like that riddled with endless delays and bad news, specially if you are asking for more money for increased production.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Tristarsteve
Posted 2010-12-12 03:42:24 and read 10772 times.

Quoting tdscanuck (Reply 153):
Quoting Tristarsteve (Reply 144):
A lot of modern aircraft have no-break transfer.
The B777 and A330 to name two.

I'm pretty sure they implement the no-break transfer by having the loads spec's to handle the brief interruption, as opposed to actually having two generators on one bus momentarily.

Quoting Tristarsteve (Reply 144):
When transferring from ground power to APU., and from APU to Engine generators, the generators are brought in-phase and actually power the bus simultaneously for a split second.

Is the electrical system actually manipulating the transmission inside the IDG to align the phases? That's the only way I can see them coming in phase, since I don't think the bus power controls have the authority to tell the APU or the engines to change speed.

This is from the A330.
With ground power supplying, and the APU is started The GPCU sends the frequency information of the Ext B to the APU GCU. If the frequency is between 390-410, the APU GCU tells the APU ECB to adjust the APU speed. When the APU frequency and phase angle match the GPCU ref signal the APU GLC closes to place the APU gen on the transfer line. After a short time delay the EXT B contactor is opened.
When the engine is started, the GPCU sends the APU frequency information to the GCU to control the IDG output. When the frequency and phase angle match IDG 1 is momentarily parralled with the APU generator.
These are milliseconds. If the sources are parralled for more than 130 ms, the contactors are opened again by the ECMUs. If they are still parralled 60ms later, both are tripped.

So yes, the electrical system is controoling the generator outputs during the switch over. When it is complete, they revert to their internal controls.

Edit This is available on the ground only, as the reference signal is taken from the GPCU which is only powered on the ground.

[Edited 2010-12-12 04:43:32]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-12 09:25:38 and read 10515 times.

Quoting Tristarsteve (Reply 158):
So yes, the electrical system is controoling the generator outputs during the switch over. When it is complete, they revert to their internal controls.

Cool! Thanks for the info, I didn't know that fine level of control was available within the power system. So how does this work with variable-frequency generators...since they're direct drive, isn't the only way to sync to actually adjust the engine speed (when we're talking about engine generator transfers)?

Quoting Tristarsteve (Reply 158):
Edit This is available on the ground only, as the reference signal is taken from the GPCU which is only powered on the ground.

How does this work in the air? Or do you just get a break power transfer then?

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: BoeingVista
Posted 2010-12-13 19:34:54 and read 9973 times.

In context of the fire on the 787 and discussion on the 787 QRH these Boeing comments are quite interesting which made it into the final report of the total power outage on a QF 747 near Bangkok 7/1/07 If you remember water from faulty plumbing got into the EE bay causing a total loss of electrical power, the aircraft reverted to battery power and only had 14 minutes remaining on landing.

The ATSB wanted Boeing to create a Non normal checklist, Boeing said that they couldn't and the FAA backed Boeing.

Quote:
While both the US plane maker and its equivalent to CASA and Qantas and the ATSB have all agreed upon a whole range of actions to address the Australian maintenance failures and oversights that caused the electrical failures on the 747-400 that was operating QF2 from London to Sydney via Bangkok when it suffered a range of electrical and control problems there were disagreements.

One concerned the ATSB finding that the flight crew quick reference handbook of QRH for the 747-400 did not include sufficient information for the pilots to ” appropriately manage operations on standby power”.

To cut to the chase, Qantas said it would alter the QRH if Boeing approved the changes, and Boeing refused to.

Boeing said it had spent considerable time and resources trying to devise a non normal checklist that would cover the situation that affected the Qantas jet but was “unable to come up with a NNC that would cover the subject event for all 747 configurations in the fleet.” It also believed that one NNC “cannot be useful as well as correct for all conditions that might lead to the situation involving reliance on standby power.”

So Zeke, it looks like the blanks will not be filled in in the QRH, its supposed to be that way! as they can't create a single NNC regarding standby power they would rather do nothing, to me this seems odd. Interesting that the two regulatory bodies disagree.

From crikey http://blogs.crikey.com.au/planetalk...and-boeing-tell-atsb-we-know-best/

From the report

Quote:
The ATSB acknowledges the reviews already undertaken by the aircraft operator and manufacturer and action to amend the operator’s operations manual to include guidance to flight crews on the effect and management of multiple AC electrical bus loss, including on battery life. The ATSB recognises that the various crew alerting systems in the 747‑400 should inform flight crews of any aircraft systems that are be affected by electrical systems failures.

However, there is currently limited assurance that 747-400 flight crews would be aware of the expected duration of available battery power or of the possible need to expedite appropriate actions such as aircraft diversion that should be undertaken in the event of abnormal or unexpected battery discharge. The inclusion of a note or caution associated with the battery discharge message entry in the QRH to alert crews of the restricted battery life in such cases would help crews select and prioritise the most appropriate actions to recover from the emergency.

The ATSB (makes) safety recommendation AO-2008-003-SR-108

The Australian Transport Safety Bureau recommends that the aircraft manufacturer undertake further work to address this safety issue.


[Edited 2010-12-13 19:37:05]

[Edited 2010-12-13 19:38:16]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-13 21:06:47 and read 9837 times.

Quoting BoeingVista (Reply 160):
So Zeke, it looks like the blanks will not be filled in in the QRH, its supposed to be that way! as they can't create a single NNC regarding standby power they would rather do nothing, to me this seems odd.

The electrical, hydraulic, and flight controls architectures of the 787 and 747 are radically different, as is the difference between derivatives on the 747 that doesn't apply to the 787. The fact that Boeing has a perceived QRH hole on this issue on the 747 doesn't have much bearing on the 787...for starers, the 787 *does* have a QRH for dropping all the way to standby power.

Tom

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-13 23:52:37 and read 9689 times.

Quoting BoeingVista (Reply 160):
Interesting that the two regulatory bodies disagree.

The ATSB is not a regulator, it is the investigator. The equivalent in USA is the NTSB. The FAA also will not endorse some NTSB recommendations is they do not believe it will be beneficial (which may include a cost/benefit analysis).

Quoting tdscanuck (Reply 161):
*does* have a QRH for dropping all the way to standby power.

And what would that be ? I see 12 electrical procedures, none of them covering that.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-14 06:07:50 and read 9224 times.

Quoting zeke (Reply 162):
And what would that be ? I see 12 electrical procedures, none of them covering that.

It's the four ELEC AC BUS x (x = L1, L2, R1, R2) checklists. The 787 has electronic checklists, you just run 'em in order and the notes (like what systems are inop) are combined by the checklist system into a single list.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-14 07:01:59 and read 9139 times.

Quoting tdscanuck (Reply 163):

It's the four ELEC AC BUS x (x = L1, L2, R1, R2) checklists. The 787 has electronic checklists, you just run 'em in order and the notes (like what systems are inop) are combined by the checklist system into a single list.

I do not agree with your logic, the checklists you mention do not cover flight in standby. The notes associated with the 4 QRH checklists (not "a QRH") do not cover all the systems lost when on standby.

While shutting down the whole 235 VAC bus is a way to get into standby, it is not the only way. As we saw from the fire, some 235 VAC busses can remain powered and displays in the cockpit can still have a power interruption (they are on the 28 VDC bus), the trigger for the RAT deployment.

The 787 has no checklist for flight on the standby, or flight on standby bus and some others powered.

I also have not seen anything to suggest the APU can power all the AC busses in flight.

The 787 also has no checklist (like found on other types) for the crew to follow to shutdown all electrical busses and fly on standby in the event of an electrical fire of unknown source. Something I find very odd for an aircraft so reliant on its electrical systems.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: WestWing
Posted 2010-12-14 21:07:42 and read 8575 times.

December 15th.

Lest we forget, a year has now passed since the maiden flight of the 787. Boeing would like to have been in a celebratory mood today, but with the grounded fleet and current situation - the anniversary may just fly quietly by.

[Edited 2010-12-14 21:09:05]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-14 21:07:46 and read 8574 times.

Quoting zeke (Reply 164):
I do not agree with your logic, the checklists you mention do not cover flight in standby. The notes associated with the 4 QRH checklists (not "a QRH") do not cover all the systems lost when on standby.

QRH checklists almost never cover the full systems effects...that's what the FCOM is for. The QRH specifies actions required by the flight crew, not systems descriptions. Just as a trivial example, the ENG FAIL checklist doesn't say anything about the fact that you've lost two generators or that the thrust reverser on that side won't function. The QRH assumes that it's being used by a crew who knows the FCOM. The QRH provides all the appropriate actions for the flight crew to take, which is what it's for.

Quoting zeke (Reply 164):
While shutting down the whole 235 VAC bus is a way to get into standby, it is not the only way. As we saw from the fire, some 235 VAC busses can remain powered and displays in the cockpit can still have a power interruption (they are on the 28 VDC bus), the trigger for the RAT deployment.

Exactly why QRH procedures are based on system-effects, and you combine procedures for combined effects. The 787 has 15 discrete power buses of various sorts...if you wanted a QRH procedure for all 32,768 possible failure combinations, I think we're have to remove the "Q" from the title.

Quoting zeke (Reply 164):
The 787 has no checklist for flight on the standby, or flight on standby bus and some others powered.

Do you really want dedicated checklists for all possible combinations? You have checklists for loss of all the systems that require any flight crew action. Whatever combination of things you've lost to put you in standby power, you've got a checklist to cover the actions that the flight crew needs to take. You don't put things in the QRH for information only. For example, if you lose the hot battery bus there's nothing the flight crew can do about it, so there's no QRH procedure.

What flight crew action do you feel is missing that needs to be there?

Quoting zeke (Reply 164):
I also have not seen anything to suggest the APU can power all the AC busses in flight.

If it couldn't, you couldn't restart the engines in flight. The 787 has four engine generators and four primary AC buses. The generators are also the starters, so you need to be able to power a bus to start the engine. And you can dispatch with a generator inop, so the APU must be capable of powering *all* of the starters, which means it's capable of powering *all* of the AC buses.

Quoting zeke (Reply 164):
The 787 also has no checklist (like found on other types) for the crew to follow to shutdown all electrical busses and fly on standby in the event of an electrical fire of unknown source. Something I find very odd for an aircraft so reliant on its electrical systems.

It's in the "Smoke, Fire or Fumes" checklist in two branches...there are only three places you can have an unknown electrical fire...one of the EE bays or the cabin. If it's in an EE bay, you know where it is (smoke detection messages are location specific), which which case it instructs you to depower the affected equipment. If it's in the cabin, you depower the cabin.

Tom.

[Edited 2010-12-14 21:11:11]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Daysleeper
Posted 2010-12-15 04:32:27 and read 8315 times.

I haven;t read this thread for a while so scanned though to catch up. Is the basics of this now that the bus failed due to an overload? and then subsequently the "logic" in the power system failed to compansate leaving the crew with the absolute basics from the RAT?

It would be good to summarise this, the thread to me now reads like the OJ Simpson trail with some aspects of it being discussed in such detail that its difficult to see the big picture.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-15 06:09:40 and read 8242 times.

Quoting Daysleeper (Reply 167):
Is the basics of this now that the bus failed due to an overload?

The basics, according to Boeing press releases and leaked stuff to the press, are that some kind of FOD shorted out the P100 power panel. This isn't really an overload.

Quoting Daysleeper (Reply 167):
nd then subsequently the "logic" in the power system failed to compansate leaving the crew with the absolute basics from the RAT?

Something happened that resulted in temporary failure of all primary AC power...it's not clear if the power system failed to compensate at all, or actively compensated wrong. The crew was down to battery and RAT power ("the basics") but retained full control of the airplane and some amount of diversion capability. There are a bunch of open questions, which is the basis of most of the detailed discussion:
-Since this happened only a minute or so before landing, was the system in the process of recovering or was it in its final state? I.e. could they have started the APU or had engine generators recover if they'd had more time?
-If this had happened at cruise in an ETOPS flight, what are the chances of a successful diversion?
-How exactly is the 787 power system configured (what feed whats)?
-How bad was the fire, would it have required extra firefighting steps if they'd been in the air longer, etc.?
-Were the flight crew instructions (FCOM, QRH, etc.) adequate to handle this situation in service?
-When will they return to flight, to certification, finish testing, and EIS?
-What exactly needs to change in the power system, how long will that take, and how will it impact testing already performed?

Several posters, myself included, have their own strong and differing opinions on this. You can reread the thread searching for keywords if you want to find those.

You can infer reasonable answers to a lot of this stuff from available information, but we can't be sure and, depending on your level of trust in Boeing (from "trying their best to be honest" to "stinking liars") you get different "reasonableness".

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: mdword1959
Posted 2010-12-15 06:18:37 and read 8205 times.

Quoting tdscanuck (Reply 168):

Thanks for the thorough recap Tom. It will be interesting to see if there will be an "official" update forthcoming before the year-end (holiday) break beginning at the end of next week..

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-15 06:36:26 and read 8169 times.

Quoting tdscanuck (Reply 166):
QRH checklists almost never cover the full systems effects...that's what the FCOM is for.

I am not suggesting to cover everything, just the glaring missing checklist for flight on standby power only.

Quoting tdscanuck (Reply 166):
Just as a trivial example, the ENG FAIL checklist doesn't say anything about the fact that you've lost two generators or that the thrust reverser on that side won't function.

That checklist is not an engine fail checklist, i.e. is is not a checklist on how to fail an engine, it is a combined engine restart and engine shutdown checklist. It is something I would not expect to see in the QRH, it should just be an electronic checklist.

Quoting tdscanuck (Reply 166):
The QRH assumes that it's being used by a crew who knows the FCOM.

Pilots will have checked that box when they do the type rating. The retention of information will decrease with time, and even less so at a 4am body clock time after three all night shifts in a row.

Quoting tdscanuck (Reply 166):
The QRH provides all the appropriate actions for the flight crew to take, which is what it's for.

What "appropriate actions" should crew do when they are flying on standby only ?

Quoting tdscanuck (Reply 166):
Exactly why QRH procedures are based on system-effects, and you combine procedures for combined effects. The 787 has 15 discrete power buses of various sorts...if you wanted a QRH procedure for all 32,768 possible failure combinations, I think we're have to remove the "Q" from the title.

The example is flawed, where does any of the 4 individual checklists say that autothrottle or pressurisation is unavailable. It would normally be available with a single bus failure, however unavailable in standby.

Quoting tdscanuck (Reply 166):
Do you really want dedicated checklists for all possible combinations?

No, however I would expect the worst case to covered.

Quoting tdscanuck (Reply 166):
You don't put things in the QRH for information only.

Suggest you look at the sections after and including “Operations Information”.

Quoting tdscanuck (Reply 166):
What flight crew action do you feel is missing that needs to be there?

How to isolate the aircraft from the unessential electric busses.

Quoting tdscanuck (Reply 166):
If it couldn't, you couldn't restart the engines in flight.

No, you are talking about connecting an APU output to a single bus, I was specific in that it unable to "power all the AC busses in flight".

Quoting tdscanuck (Reply 166):
And you can dispatch with a generator inop, so the APU must be capable of powering *all* of the starters, which means it's capable of powering *all* of the AC buses.

Not at the same time.

Quoting tdscanuck (Reply 166):
there are only three places you can have an unknown electrical fire...one of the EE bays or the cabin.

Anywhere in the 61 miles of wiring that is not in the EE bay, on the flight deck, galley, any electrical motor/pump (inc fuel tank), windshield etc.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: Daysleeper
Posted 2010-12-15 06:40:20 and read 8153 times.



Quoting tdscanuck (Reply 168):



Thanks alot for this. Seems a very open minded unbiased summary.

In regards to firefighting, I thougth Boeing had stated that it did self-extinguish? Therefore no further firefighting steps were needed..

I also thought it was "fact" that if the RAT deployed that all primary power had been lost. Well Primary as in P100 and P200. APU and Battery I would assume would be available.

[Edited 2010-12-15 06:42:11]

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-15 10:58:23 and read 7929 times.

Quoting zeke (Reply 170):
I am not suggesting to cover everything, just the glaring missing checklist for flight on standby power only.

But a dedicated checklist for "flight on standby power" wouldn't contain any information that wasn't already in the various system checklists. What's gained by repackaging existing data into another list?

Quoting zeke (Reply 170):
That checklist is not an engine fail checklist, i.e. is is not a checklist on how to fail an engine, it is a combined engine restart and engine shutdown checklist. It is something I would not expect to see in the QRH, it should just be an electronic checklist.

It *is* in the QRH. It's the crew response to the EICAS message "ENGINE FAIL L,R".

Quoting zeke (Reply 170):
What "appropriate actions" should crew do when they are flying on standby only ?

Follow the checklists for the inop systems, exactly as you'd do for any other system failure. I guess that's my fundamental misunderstanding of your request...why does this specific failure (which is phenomenally unlikely on an in-service aircraft) warrant a dedicated checklist when so many other combination failures that are more likely do not have a dedicated checklist?

Quoting zeke (Reply 170):
The example is flawed, where does any of the 4 individual checklists say that autothrottle or pressurisation is unavailable

They don't...but if autothrottle or pressuzation become unavailable, you get an AUTOTHROTTLE L+R and CABIN PRESS (or words to that effect) EICAS message, and each of those has its own checklist, when necessary. Putting it in the QRH is redundant.

Quoting zeke (Reply 170):
Quoting tdscanuck (Reply 166):
You don't put things in the QRH for information only.

Suggest you look at the sections after and including “Operations Information”.

That's information *required to operate the aircraft by the checklists*. Putting all the FCOM information, like what systems are avialable on standby power, into the QRH provides no gain and reduces the usefulness of the QRH.

Quoting zeke (Reply 170):
Quoting tdscanuck (Reply 166):
What flight crew action do you feel is missing that needs to be there?

How to isolate the aircraft from the unessential electric busses.

Turn off the generators. Instructions to do so are in the QRH already.

Quoting zeke (Reply 170):
Quoting tdscanuck (Reply 166):
If it couldn't, you couldn't restart the engines in flight.

No, you are talking about connecting an APU output to a single bus, I was specific in that it unable to "power all the AC busses in flight".

I know you were specific, and since the 787 can do simultaneous dual-engine start (two starters per engine), so was I. The APU can run all buses at once.

Quoting zeke (Reply 170):
Quoting tdscanuck (Reply 166):
And you can dispatch with a generator inop, so the APU must be capable of powering *all* of the starters, which means it's capable of powering *all* of the AC buses.

Not at the same time.

Yes, at the same time. This is what bus-tie breakers were invented for.

Quoting zeke (Reply 170):
Quoting tdscanuck (Reply 166):
there are only three places you can have an unknown electrical fire...one of the EE bays or the cabin.

Anywhere in the 61 miles of wiring that is not in the EE bay, on the flight deck, galley, any electrical motor/pump (inc fuel tank), windshield etc.

The flight deck, galley, and windshield are part of the cabin. They're all covered by the existing fire/smoke/fume checklist. Fire in an electrical motor/pump like in a fuel tank is completely invisible to the crew...there is no fire detection or overheat detection in any fuel system on any aircraft I'm aware of.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-15 16:50:37 and read 7600 times.

Quoting tdscanuck (Reply 172):
But a dedicated checklist for "flight on standby power" wouldn't contain any information that wasn't already in the various system checklists.

Yes it would, like the systems that are available. Flight on standby power is a mayday situation, crew need to have the information at hand, not stuck away is some other document the manufacturer thinks they should be able to find in such a stressful environment.

No pressurisation would cue the crew to protect the cabin altitude, and to protect themselves with oxygen. It may require and emergency descent, and the lack of auto throttle could mean things could get interesting at the bottom of an emergency descent (menas nothing over flat countryside, however with a MEA of FL250 it is a differnt ball game) when the aircraft is levelling off with no thrust on, or the worse case, starting the emergency descent with no auto throttle, thrust at cruise level, commencing a descent thrust not reducing causing an over speed.

Quoting tdscanuck (Reply 172):
What's gained by repackaging existing data into another list?

To deal with the mayday, remember the FO does not have their DUs available.

Quoting tdscanuck (Reply 172):
It *is* in the QRH. It's the crew response to the EICAS message "ENGINE FAIL L,R".

The subtilises have been lost on you. The actual checklist is a combined engine relight or engine shutdown as that is what the crew is doing.

Quoting tdscanuck (Reply 172):
I guess that's my fundamental misunderstanding of your request...why does this specific failure (which is phenomenally unlikely on an in-service aircraft) warrant a dedicated checklist when so many other combination failures that are more likely do not have a dedicated checklist?

Checklists should be available for mayday situations, crews should have available clear tested guidance on how to handle the emergency, and should be able to practice the checklist in the simulator.

Quoting tdscanuck (Reply 172):
Putting it in the QRH is redundant.

That is your view, however with respect, you are not the end use of such a document. From an operational point of view, I know what I want to be in a QRH, and need to assume that the guy next to me might only have 200 hours total experience, and it could be me that become incapicated in-flight. Checklists need to cover the lowest common denominator, not test pilot level.

Quoting tdscanuck (Reply 172):
Putting all the FCOM information, like what systems are avialable on standby power, into the QRH provides no gain and reduces the usefulness of the QRH.

That is your view. In an emergency situation the crew needs a single referance to work through methodically, what you are saying is acceptable is to jump from a QRH, electronic checklist, and also FCOM while doing an emergency descent. It is an unrealistic expectation.

Quoting tdscanuck (Reply 172):
I know you were specific, and since the 787 can do simultaneous dual-engine start (two starters per engine), so was I. The APU can run all buses at once.

I have seen nothing to suggest to can do that in air. Most aircraft have different APU bus tie configurations for on ground and in air operations. Care to point out where in any of the documents it says the APU can power all busses whilst airborne ?

Quoting tdscanuck (Reply 172):

The flight deck, galley, and windshield are part of the cabin.

The checklist does not cover a fire on the flight deck or windshield. Also the checklist does not include instructions on how to "Turn off the generators" or in what order, and over what time frame that should be achieved.

The QRH gives no guidance at all how to combat the fire which occurred in the 787 flight test. The current smoke/fire/fumes checklist would not have cut-off the fuel to the fire (i.e. the generators).

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: YVRLTN
Posted 2010-12-15 18:57:01 and read 7501 times.

http://aviation-safety.net/news/newsitem.php?id=2145

Sound familiar?

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-15 23:14:47 and read 7347 times.

Quoting zeke (Reply 173):
Checklists should be available for mayday situations, crews should have available clear tested guidance on how to handle the emergency, and should be able to practice the checklist in the simulator.

Aside: how is putting an airplane into a situation it's certified to operate in safety for 6 hours a mayday situation?

Even if we allow that it's a mayday situation, you do have available clear tested guidance on how to handle the emergency, and you can practice it in the simulator. Inject the failure, EICAS messages appear, follow the checklists for the relevant message. The failure of all systems taken down by going to standby power is covered by existing checklists. The only difference is how many checklists you have to run (and you're never going to get it to one for an event this complex).

Quoting zeke (Reply 173):
That is your view, however with respect, you are not the end use of such a document.

Actually, I am.

Quoting zeke (Reply 173):
From an operational point of view, I know what I want to be in a QRH, and need to assume that the guy next to me might only have 200 hours total experience, and it could be me that become incapicated in-flight. Checklists need to cover the lowest common denominator, not test pilot level.

Agreed. But I think we're arguing about checklist format, not content. So far, I still don't see what's missing from the existing QRH. What action/information that the flight crew needs to know isn't already provided by EICAS and the associated checklists (the QRH checklists and electronic checklists are identical, they're just different formats).

Quoting zeke (Reply 173):
In an emergency situation the crew needs a single referance to work through methodically, what you are saying is acceptable is to jump from a QRH, electronic checklist, and also FCOM while doing an emergency descent. It is an unrealistic expectation.

QRH and electronic checklist are redundant...you can use either. They have the same content. I'm *not* advocating pulling out the FCOM in the middle of an emergency.

Quoting zeke (Reply 173):
Care to point out where in any of the documents it says the APU can power all busses whilst airborne ?

It says it can power them all on the ground, and it says that the only difference in air is that you're on one ASG instead of two. The extremely conspicuous lack of any discussion that you lose some AC buses in the air on APU is all the documentation I think is necessary.

Quoting zeke (Reply 173):
The checklist does not cover a fire on the flight deck or windshield. Also the checklist does not include instructions on how to "Turn off the generators" or in what order, and over what time frame that should be achieved.

1) The checklist does cover a flight deck or windshield fire. That would fall under "source of the smoke, fire, or fumes is obvious and can be extinguished quickly:"
2) The checklist doesn't include instructions to turn off the generators any more than the normal procedures include instructions on how to "turn the airplane". There's a switch on the overhead panel that says generator - ON/OFF. It's part of basic pilot training to know how to turn systems on and off.
3) The order doesn't matter, so why would you specify it?
4) How would you specify the timeframe in any way that could be applicable to the wide variety of situations in which that checklist could be employed? Room has to be left for pilot judgement to determine what "quickly" means relative to the current emergency and state of the aircraft.

Quoting zeke (Reply 173):
The QRH gives no guidance at all how to combat the fire which occurred in the 787 flight test. The current smoke/fire/fumes checklist would not have cut-off the fuel to the fire (i.e. the generators).

That's a matter of judgement...you've got a plane full of trained engineers. The source of the fire may well have been "obvious" and we know it was extinguished quickly. That would point you at "if practical, remove power from the affected equipment by switch or circuit breaker in the flight deck or cabin." If you had an identified fire in the power panel that takes your left engine generators, wouldn't you think to turn off your left engine generators?

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: zeke
Posted 2010-12-17 19:55:10 and read 6788 times.

Quoting tdscanuck (Reply 175):
Aside: how is putting an airplane into a situation it's certified to operate in safety for 6 hours a mayday situation?

Loss of pressurization and an emergency descent, and whatever triggered the move into standby power in the first place.

Quoting tdscanuck (Reply 175):
The failure of all systems taken down by going to standby power is covered by existing checklists.

Not a single checklist covers flight on standby.

Quoting tdscanuck (Reply 175):
The only difference is how many checklists you have to run (and you're never going to get it to one for an event this complex).

One does not know which ones to ignore. That is what the QRH is for, it tells you which checklists to ignore.

Quoting tdscanuck (Reply 175):
Actually, I am.

You do not work for a Boeing customer, nor are you an airline pilot. Please do not try and misrepresent things even further.

Quoting tdscanuck (Reply 175):
QRH and electronic checklist are redundant...you can use either

No, the QRH tells you which electronic checklists to ignore.

Quoting tdscanuck (Reply 175):
The extremely conspicuous lack of any discussion that you lose some AC buses in the air on APU is all the documentation I think is necessary.

This a retraction on your previous comment that the APU can power all AC busses in flight ?

Quoting tdscanuck (Reply 175):
The checklist does cover a flight deck or windshield fire. That would fall under "source of the smoke, fire, or fumes is obvious and can be extinguished quickl

No, windshield and cockpit fires normally originate from places that are covered, one cannot get access to them, so I cannot see how the origin would be obvious.

Quoting tdscanuck (Reply 175):
The checklist doesn't include instructions to turn off the generators any more than the normal procedures include instructions on how to "turn the airplane". There's a switch on the overhead panel that says generator - ON/OFF. It's part of basic pilot training to know how to turn systems on and off.

Any 3 year old can turn a switch on and off, however pilots are trained with SOP and checklists. They do not turn anything on or off unless it is specified by procedure. That can as simple as turning on the taxi light before taxi, turning on the strobes before entering the runway, these are simple switches that have no adverse effects on the aircraft. Turning off a generator however is not something anyone would just do without consulting a checklist first, it can have adverse effects on aircraft systems.

Quoting tdscanuck (Reply 175):
The order doesn't matter, so why would you specify it?

Turning off a generator does not unpower a bus, it just opens the generator control breaker, and "any engine generator is not available, its related main bus is energized by another main 235 Vac bus". The manuals do not say what the systems takes care of with the Load inhibit and Load shed.

So turning off a generator does not achieve the aim of removing power from the bus.

Quoting tdscanuck (Reply 175):
How would you specify the timeframe in any way that could be applicable to the wide variety of situations in which that checklist could be employed?

The smoke/fire/fumes checks lists includes time frames in it to give some time for smoke to dissipate, or to see if the fire is getting worse. Any switch change will not result in an immediate change to the fire, it will take time for any switch change to make an impact. You will notice they have a 2 minutes wait in the checklist already following some different switch position changes.

Quoting tdscanuck (Reply 175):
The source of the fire may well have been "obvious" and we know it was extinguished quickly.

Flightglobal indicated that the fire was on the rear side of the panel causing a foot long burn.

Quoting tdscanuck (Reply 175):
If you had an identified fire in the power panel that takes your left engine generators, wouldn't you think to turn off your left engine generators?

That does not remove power from the bus, it opens the generator control breaker.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: tdscanuck
Posted 2010-12-17 21:10:10 and read 6747 times.

Quoting zeke (Reply 176):
Not a single checklist covers flight on standby.

I certainly agree, no *single* checklist covers this situation. But I also think we've drifted a long way (probably too far) from the original topic of the thread into general QRH/checklist/emergency procedures and we're not really talking the 787 event of interest anymore. I think we'll just have to go with "Agree to disagree."

Quoting zeke (Reply 176):
You do not work for a Boeing customer, nor are you an airline pilot. Please do not try and misrepresent things even further.

I never represented myself as working for a Boeing customer, nor as an airline pilot. However, as I'm sure you're aware, those are not the only end users of a QRH.

Just for clarity of record, I do *not* currently work for any Boeing customer (although I have in the past) and I am *not* an airline pilot.

Tom.

Topic: RE: 787 Test Flight Evacuated Due To Smoke - Part 3
Username: ManuCH
Posted 2010-12-19 08:27:45 and read 6153 times.

Unfortunately, this thread has veered off-topic. Therefore it will now be locked.

Please feel free to start part 4 should any new information be available, but make sure to stick to the topic being discussed. Specifics about very technical topics (smoke detectors, checklists, etc) should be discussed in a separate thread in Tech/Ops.


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