moderators From United States of America, joined Apr 2004, 459 posts, RR: 0 Posted (2 years 5 months 2 weeks 5 days 13 hours ago) and read 22581 times:
Stitch From United States of America, joined Jul 2005, 26700 posts, RR: 83 Reply 1, posted (2 years 5 months 2 weeks 5 days 13 hours ago) and read 22572 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.
Revelation From United States of America, joined Feb 2005, 10456 posts, RR: 20 Reply 2, posted (2 years 5 months 2 weeks 5 days 13 hours ago) and read 22544 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?
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.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 3, posted (2 years 5 months 2 weeks 5 days 12 hours ago) and read 22364 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.
dynamicsguy From Australia, joined Jul 2008, 766 posts, RR: 8 Reply 4, posted (2 years 5 months 2 weeks 5 days 11 hours ago) and read 22296 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
packsonflight From Iceland, joined Jan 2010, 321 posts, RR: 0 Reply 5, posted (2 years 5 months 2 weeks 5 days 9 hours ago) and read 22107 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.
slz396 From , joined Dec 1969, posts, RR: Reply 7, posted (2 years 5 months 2 weeks 5 days 9 hours ago) and read 22000 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!
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.
dynamicsguy From Australia, joined Jul 2008, 766 posts, RR: 8 Reply 8, posted (2 years 5 months 2 weeks 5 days 9 hours ago) and read 21965 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.
JoeCanuck From Canada, joined Dec 2005, 5025 posts, RR: 29 Reply 9, posted (2 years 5 months 2 weeks 5 days 9 hours ago) and read 21962 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.
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?
JoeCanuck From Canada, joined Dec 2005, 5025 posts, RR: 29 Reply 11, posted (2 years 5 months 2 weeks 5 days 8 hours ago) and read 21821 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.
Stitch From United States of America, joined Jul 2005, 26700 posts, RR: 83 Reply 12, posted (2 years 5 months 2 weeks 5 days 7 hours ago) and read 21704 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.
packsonflight From Iceland, joined Jan 2010, 321 posts, RR: 0 Reply 13, posted (2 years 5 months 2 weeks 5 days 7 hours ago) and read 21659 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.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 15, posted (2 years 5 months 2 weeks 5 days 5 hours ago) and read 21436 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).
Bennett123 From United Kingdom, joined Aug 2004, 6358 posts, RR: 1 Reply 16, posted (2 years 5 months 2 weeks 5 days 5 hours ago) and read 21393 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?.
keesje From , joined Dec 1969, posts, RR: Reply 17, posted (2 years 5 months 2 weeks 5 days 5 hours ago) and read 21392 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.
kaiarahi From Canada, joined Jul 2009, 2579 posts, RR: 24 Reply 18, posted (2 years 5 months 2 weeks 5 days 5 hours ago) and read 21387 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.
BoeingVista From Australia, joined Jan 2009, 1011 posts, RR: 2 Reply 19, posted (2 years 5 months 2 weeks 5 days 3 hours ago) and read 21251 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
XT6Wagon From United States of America, joined Feb 2007, 3130 posts, RR: 4 Reply 21, posted (2 years 5 months 2 weeks 5 days 3 hours ago) and read 21209 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.
Stitch From United States of America, joined Jul 2005, 26700 posts, RR: 83 Reply 23, posted (2 years 5 months 2 weeks 5 days 2 hours ago) and read 21169 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?).
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 24, posted (2 years 5 months 2 weeks 5 days 2 hours ago) and read 21165 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.
25 wolbo: From the posted article this part seems relevant to our ongoing discussion:
26 JoeCanuck: If a typical flight profile includes ETOPS, then Boeing is indeed saying it could have completed a mission at max ETOPS range. Indeed. The FAA hasn't
27 BoeingVista: 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
28 JoeCanuck: I thought the FAA did ground the fleet. We could go on strike...that'd learn 'em...
29 tdscanuck: Rain-in-the-plane is endemic to all pressurized airliners. Estimates vary, but most aircraft are packing several hundred pounds of water in their ins
30 JoeCanuck: 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
31 BoeingVista: None, AFAIK the 787 has only gone TATL far as the UK and you don't need ETOPS for that Or you have a failure mode associated with wear a'la Trent 900
32 TheRedBaron: 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
33 JoeCanuck: 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
35 dynamicsguy: 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
36 BoeingVista: 14. Asserting that the dead horse was still capable of fulfilling a typical mission profile[Edited 2010-12-05 23:22:54]
37 packsonflight: There is a big difference between flight instruments and displays. Many screens in the 787 and instrument switching between them takes care of the pr
38 slz396: ROTFL Interestingly enough, Boeing has been using this method already in the past too, didn't they? Still remember their hilarious comments when they
39 kaiarahi: Just like Toyota, GM, Volkswagen, IBM, Dell, GE, Whirlpool, KitchenAid, Phillips, LG, Samsung, Caterpillar, Volvo, Ryobi, DeWalt .... It would be nic
40 slz396: 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
41 tdscanuck: Absolutely...huge maintenance benefit. But "rain-in-the-plane" usually specifically refers to the annoying habit of condensation dripping on the pax,
42 slz396: 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-t
43 packsonflight: What are you refering to as "critical insturment busses"? is it the L&R instruuments or the STBY insturments Are you refering to primary instrume
44 TheRedBaron: Well Toyota thought they had nailed down the pedal accelerators and systems of their cars ( a lot less complex) and the failed. Remember stupidity an
45 rcair1: 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, poi
46 kaiarahi: I don't know when you looked at the QF A380 thread, but the official ATSB report has been posted for about 5 days.
47 JoeCanuck: I would also be interested in any documentation that contradicts any claims made by Boeing. For instance, typical mission profile doesn't specificall
48 kaiarahi: 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-u
49 Revelation: That's a pretty ugly slur on the Bible and a personal insult to many a.net members, if you ask me. What is "completely meaningless" about "could have
50 bikerthai: Apples and Oranges yes . . . Example given does not prove the statement however. Boeing did " nailed down the "mission profile" of their vehicles (ma
51 litz: I'm sure Carnival is asking the same exact question right now ... (how odd was it that two completely different transportation systems had electrical
52 dynamicsguy: 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, manuf
53 BoeingVista: 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 Homm
54 AAExecPlat: 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
55 BoeingVista: 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
56 dynamicsguy: 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
57 JoeCanuck: Boeing isn't required to tell posters anything, including specifics about what is typical. Until someone comes up with any mission that could possibl
58 keesje: Is this in anyway related to increased humity, a slelling point of the Dreamliner? Nothing. Although recently I posted a thread on the 737-900ER beco
59 BoeingVista: 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
60 thediplomat: Don't flatter yourself keesje. neither you nor anet has anywhere near that level of influence.
61 rcair1: Thanks - but I read it the day it came out. Kudos to them for being quick.
62 kanban: 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
63 Zeke: 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 thi
64 JoeCanuck: 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 o
65 tdscanuck: The typical mission profile would be defined in the design requirements and objectives document, something that had to have been written before anyon
66 slz396: Indeed and yet this undeniable observation apparently greatly annoys certain people here, who absolutely want to proof that this is not the case and
67 slz396: 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
68 packsonflight: 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 t
69 XT6Wagon: 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 pow
70 packsonflight: 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 power
71 slz396: we are starting to talk events as on any normal transtatlantic trip during winter. Image the same problem would have happened on an oceanic crossing
72 keesje: 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 themse
73 slz396: 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
74 slz396: 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 rea
75 JoeCanuck: They are saying something meaningful...to most people. Judging from this thread alone, most posters have taken meaning from Boeing statements...so, b
76 rheinwaldner: 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 fo
77 Revelation: Indeed. Thanks for your patience, Tom, in providing as much information as you have. I wouldn't describe your rendering as analytical, I'd call it co
78 slz396: Several posters have come up with perfectly plausible real world situations any long haul plane can encounter on a day-to-day mission, situations whi
79 slz396: The number of people buying a certain explanation is irrelevant as proof of its truth.... Besides, credibility is gained by making valid points, not
80 slz396: 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 l
81 Revelation: Failure to retract your statement about "meaningless" comments when their meaning has repeatedly been explained to you also comes in handy when one w
82 tdscanuck: Agreed. Why does this icing red-herring keep coming up? Natural icing tests are done *with anti-ice off*. *All* of the above is included in the fligh
83 rottenray: 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
84 Zeke: 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
85 slz396: Natural icing tests are NOT centered on a plane with its RAT down and take into account moderate icing conditions only. Actually, only with reference
86 Zeke: The industry consensus on cabin/electrical fire is that around 15-20 minutes is available. That has come from events like Swissair 1111, Saudi Arabia
87 slz396: 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 h
88 Zeke: 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 co
89 slz396: 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 soun
90 rottenray: 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. Thi
91 zeke: 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
92 ER757: 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 o
93 bikerthai: Let's decouple the two question and see if we can get an agreement. Would the pilot then drop down to a reasonable altitude if the plane is 2 hrs away
94 zeke: 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 f
95 ER757: Thanks for the quick reply - here's hoping you never have to face this choice!!
96 b78710: I doubt it, Battery bus or standby bus maybe, but not the hot battery bus.
97 JoeCanuck: 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 th
98 ADent: 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 los
99 tdscanuck: 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/autofl
100 zeke: 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 possib
101 slz396: 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, secon
102 Klaus: 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
103 bikerthai: 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 fr
104 Gordomatic: No, due to the fact ZA002 does not have an interior. Reply 236 from part 1 of this thread: "ZA002 doesn't have an interior. The sidewalls and full EC
105 bikerthai: 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 on
107 kanban: 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 "f
108 justloveplanes: 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
109 JoeCanuck: 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
110 kanban: he went out the cargo door ala D. B Cooper.... or was disguised as a fireman and nobody noticed
111 rcair1: 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.
112 JoeCanuck: 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 c
113 PITingres: 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 liabil
114 JoeCanuck: How many airlines are in the habit of making random flights? Generally, they flight routes repeatedly, which will result in pattern from which one mi
115 kanban: 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...
116 dakota123: I don't understand the certainty with which you write. AC generators are automatically synchronized to each other and automatically share load in man
117 tdscanuck: 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 t
118 BoeingVista: 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 *
119 2175301: I have worked in the power generation field for decades. All major power plants are manually synchronized to the grid. Only relatively small (compare
120 Caryjack: 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
121 tropical: Apologies if this has been reported already. Boeing officials 'tell Air France 787 first deliveries delayed until July 2011' http://www.straitstimes.c
122 slz396: 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 t
123 Klaus: 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 sys
124 okie: The 787 has 4 "wild" starter/generators there is no synchronization. The gens are always out of sync. and there is no load share. This has been one o
125 slz396: 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
126 Richard28: Reports of a delay in 787 deliveries until Q3 2011 http://economictimes.indiatimes.com/...uly-Report/articleshow/7071186.cms[Edited 2010-12-09 05:59:2
127 Klaus: They would have all their certifications yanked in no time if that was true.
128 tdscanuck: Sorry...Nz = normal (vertical) acceleration, GW = gross weight. For any particular gross weight, there is a maximum and minimum vertical acceleration
129 Revelation: Thanks for this and other clarifications. At least there is some benefit for some member's extremely circumspect viewing of public statements: I for
130 JoeCanuck: 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 e
131 ER757: Interesting that they told AF since they haven't even ordered the aircraft (unless they are a UFO order already on the books)
132 tarheelwings: 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 announce
133 JoeCanuck: That's just crazy talk, mister...you take that back...
134 ER757: Others maybe, but none more important or influential!
135 Bennett123: 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
136 dakota123: Getting really far afield, and mods feel free to delete, but likewise, I'm in the generation biz (an engineer by training, developing, permitting, bu
137 tdscanuck: Ancillary equipment often doesn't take the power transfers well...this isn't particularly unique to the the particular aircraft you're talking about.
138 zeke: The RAT does not power any bus directly, it goes via T/R, that T/R feeds the 28 VDC bus. Correct. Correct. That is not what FCOM says. While the powe
139 tdscanuck: 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
140 mdword1959: Guy Norris (AWST) has posted some interesting information: http://www.aviationweek.com/aw/blogs...=blogScript&plckElementId=blogDest
141 zeke: 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
142 Klaus: Does that mean yaw damper and other automatic functions? Or is even stabilizer trim disabled as well? One of the interesting points would probably be
143 tdscanuck: The FCOM doesn't, at least anywhere that I can find. The QRH does though. The APU battery provides power to spin the APU starter/generators. The ship
144 Tristarsteve: 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 g
145 bikerthai: 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
146 Klaus: So what's missing is just horizontal stabilizer trim, effectively? The elevators remain online?
147 zeke: As discussed earlier, common core still remains RAT powered (i.e. isolated), and that is what controls those systems. So your previous comment, "the
148 dakota123: 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 i
149 zeke: About double ballpark. The flight planning system looks at these scenarios and finds the worst point for this to happen on the route, it then looks a
150 nomadd22: 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 e
151 JoeCanuck: There was some hope for optimism in the article. It would be good news if they could continue test flights in January.
152 RedChili: 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 gre
153 tdscanuck: 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 g
154 Drewski2112: 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
155 tdscanuck: Nope. 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
156 JoeCanuck: 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 su
157 packsonflight: 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 prod
158 Tristarsteve: 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 t
159 tdscanuck: 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-freque
160 BoeingVista: 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
161 tdscanuck: The electrical, hydraulic, and flight controls architectures of the 787 and 747 are radically different, as is the difference between derivatives on
162 zeke: 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 th
163 tdscanuck: 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 sy
164 zeke: 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
165 WestWing: 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, b
166 tdscanuck: 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
167 Daysleeper: 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 subse
168 tdscanuck: 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
169 mdword1959: 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) brea
170 zeke: I am not suggesting to cover everything, just the glaring missing checklist for flight on standby power only. That checklist is not an engine fail ch
171 Daysleeper: 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?
172 tdscanuck: 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
173 zeke: 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 stuc
175 tdscanuck: 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 m
176 zeke: Loss of pressurization and an emergency descent, and whatever triggered the move into standby power in the first place. Not a single checklist covers
177 tdscanuck: 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
178 ManuCH: 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 avail
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