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Topic: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: holzmann
Posted 2013-04-27 09:01:58 and read 16030 times.

Say Boeing gets all 787s fixed and service resumes for both current and pending customers BUT battery issues and fires resurface within the next six months: how bad would this scenario be for the 787 and Boeing?

Discuss the scenarios and implications.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-27 09:09:27 and read 16021 times.

I expect fires are unlikely since Boeing improved the plastics (which is what burned on JL8 - not the battery cells or the electrolyte in them) to withstand significantly higher temperatures. And even if the new plastics do catch fire, they cannot burn long enough nor hot enough to breach the containment box, so they're not a concern from a regulatory and flight-safety aspect (though they would be a PR concern, of course).

Battery reliability will be the main concern. The 787 needs the APU battery to keep the APU going and you need the APU to be available to fly farther than 180 minutes from a diversion point. So if the in-flight failure rate is too high, that's going to prevent ETOPS-240 and ETOPS-330. The Ship's Battery isn't needed from an ETOPS standpoint, but a too-high in-flight failure rate might push for additional power supply redundancies for the braking system.

[Edited 2013-04-27 09:10:54]

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: justloveplanes
Posted 2013-04-27 09:18:14 and read 15930 times.

Quoting holzmann (Thread starter):

Say Boeing gets all 787s fixed and service resumes for both current and pending customers BUT battery issues and fires resurface within the next six months: how bad would this scenario be for the 787 and Boeing?

Not an problem. Solution WAY overdesigned for thermal or incendiary containment. As Stitch says, only issue left is reliability related. Reliability wasn't an issue before and so doubt it will be now.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: brilondon
Posted 2013-04-27 09:25:16 and read 15872 times.

I suppose this could go for any problem that any aircraft has. The DC-10 was grounded for a short time after the AA crash at ORD, what if...That is the same thing. There are examples of electrical motors having problems, there are problems with cars that could cause death and have to have a fix applied to them. This is no different except that it affects a very public piece of machinery that has a lot of press.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: spacecadet
Posted 2013-04-27 09:27:19 and read 15849 times.

Short answer: very bad, but also very unlikely.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: bellancacf
Posted 2013-04-27 09:28:07 and read 15820 times.

Well, there's always Elon Musk. It would make one wonder whether the current style battery could ever be made workable, because it seems that Boeing -- and the various suppliers -- have done about all that can be done with this chemistry and geometry and usage protocol. Think pleasant thoughts, folks.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: BoeingVista
Posted 2013-04-27 10:04:00 and read 15625 times.

Wrong question, question is if another issue leads to the FAA grounding the 787 within say a year, what then for the 787 and Boeing?

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Bongodog1964
Posted 2013-04-27 10:19:33 and read 15513 times.

As private Fraser continually said in Dad's Army "we're all doomed"      

Seriously Boeing have just worked their socks off to find, test and fit a solution to the battery fire problem, and along comes a Jonah wondering what the effect of another grounding would be. This is a time for the aviation industry to look to the future. The glass is half full and filling, not half empty and draining.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: twiga
Posted 2013-04-27 10:33:53 and read 15445 times.

Quoting Stitch (Reply 1):
The Ship's Battery isn't needed from an ETOPS standpoint, but a too-high in-flight failure rate might push for additional power supply redundancies for the braking system.

Stitch - not quite sure if that's correct. From Boeing's web page the ships main battery is used for braking when "towing", unless there is another use they didn't spell out, so it would have little to do with redundacies. Are we on the same page or are you thinking of something else, or redundancies when towing.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: bmacleod
Posted 2013-04-27 10:40:59 and read 15379 times.

Hopefully this will be this will be that last of the 787 battery issues. Just to note it will be at least another month before UA and NH 787s are back in operation.

I imagine all 787 carriers will want to inspect the batteries for themselves be giving the grreen light.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-27 10:58:00 and read 15276 times.

Quoting twiga (Reply 8):
Stitch - not quite sure if that's correct. From Boeing's web page the ships main battery is used for braking when "towing", unless there is another use they didn't spell out, so it would have little to do with redundacies. Are we on the same page or are you thinking of something else, or redundancies when towing.

I (and many others) have been operating under the assumption the Ship's Battery would provide power to the braking system on landing in the unlikely event that a 787 lost all four engine generators and both APU generators and was still able to successfully land at an airport.

However, we may all be incorrect in that assumption depending on how much power the system draws to perform an emergency braking on landing.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: N62NA
Posted 2013-04-27 11:03:06 and read 15221 times.

Quoting BoeingVista (Reply 6):
Wrong question, question is if another issue leads to the FAA grounding the 787 within say a year, what then for the 787 and Boeing?

Actually I think it's the "right" question. You bring up "another" question.

Now, to the question asked by the OP: If there's a problem with the "fix" on the battery, and the FAA has approved the "fix" - then I would fault the FAA 100%.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: EricR
Posted 2013-04-27 11:38:50 and read 15095 times.

The entire A380 fleet was grounded for a long period as well due to cracks in the wings, yet this did not have any long term impact on Airbus sales.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-27 12:24:16 and read 14880 times.

Quoting EricR (Reply 12):
The entire A380 fleet was grounded for a long period as well due to cracks in the wings, yet this did not have any long term impact on Airbus sales.

  

Individual frames were taken out of service to perform the fix, but the fleet as a whole was never grounded.

The closest we have come to a "grounding" with the A380 is when QF voluntarily stopped flying them for a period after QF31's engine failure.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: EricR
Posted 2013-04-27 13:24:44 and read 14610 times.

Quoting Stitch (Reply 13):

Quoting EricR (Reply 12):
The entire A380 fleet was grounded for a long period as well due to cracks in the wings, yet this did not have any long term impact on Airbus sales.

  

Individual frames were taken out of service to perform the fix, but the fleet as a whole was never grounded.

The closest we have come to a "grounding" with the A380 is when QF voluntarily stopped flying them for a period after QF31's engine failure.

You sir are correct. But the more important point is that Airbus overcame a significant issue with limited long term impacts. People have short memories. As long as no other major issues arise and the 787 lives up or exceeds expectations, then this news will be a distant memory in the near future.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: brilondon
Posted 2013-04-27 14:31:11 and read 14021 times.

Quoting EricR (Reply 12):

The entire A380 fleet was grounded for a long period as well due to cracks in the wings, yet this did not have any long term impact on Airbus sales.

That is not right, but also we have not seen a huge influx of orders for the A380 of late but that is due more to the fact that aircraft is a bit too big hence the success of both the B787 and the A350. Also the economy is crap in both North America and in Europe which would maybe produce more orders.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-27 14:38:50 and read 13897 times.

Quoting Stitch (Reply 10):
I (and many others) have been operating under the assumption the Ship's Battery would provide power to the braking system on landing in the unlikely event that a 787 lost all four engine generators and both APU generators and was still able to successfully land at an airport.

However, we may all be incorrect in that assumption depending on how much power the system draws to perform an emergency braking on landing.

Yes, if you're down to the RAT only, the Main battery supplies power for the electric brakes on rollout because the RAT can't provide power as the airplane slows below about 60 knots (?). If the Main battery were to be inop you would still have the reversers which are very effective to slow the airplane. Depending on conditions (landing speed, weather, etc) with at least 10,000ft of runway you could probably stop before the end. With less you might do a little damage but nothing catastrophic unless it's really not your day (and there's a cliff at the end).

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: flyBTV
Posted 2013-04-27 15:01:40 and read 13630 times.

Quoting 7BOEING7 (Reply 16):
If the Main battery were to be inop you would still have the reversers which are very effective to slow the airplane.

But what about in a fuel exhaustion scenario? That's one of the main situations where I can see all engine and APU generators being inop. Though I suppose a main battery failure concurrently with a fuel exhaustion incident would be pretty unlikely.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: DTW2HYD
Posted 2013-04-27 15:07:27 and read 13542 times.

Even with Elon Musk's theory ie., an underlying design issue of large cells, Boeing can always avoid fire with the help of sensors and software. If you see beyond "The Final Fix" cover story, a 787 will have more than one battery in its lifetime and Boeing will continuously improve the design and replace thru routine maintenance. No one will notice. If the large cell design is wrong Boeing may pay licensing fee to Mr. Musk and implement a new design.

We don't know how many bad batteries ANA and JAL replaced before they came out with the problem.

Change is difficult and every one wants to have NiCd, but we have to appreciate Boeing's efforts. 5-10 years from now every aircraft manufacturers will be using LiOn.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: ER757
Posted 2013-04-27 15:17:15 and read 13429 times.

Quoting BoeingVista (Reply 6):
question is if another issue leads to the FAA grounding the 787 within say a year, what then for the 787 and Boeing?

That is what my concern would be. I think the battery issue won't re-surface, but wondering if some other problem may surface which is more serious than routine "teething issues." I sure hope not, I am a huge fan of the 787 and wish it much success - but another serious problem arising would be a hard blow to recover from.

Quoting brilondon (Reply 3):
The DC-10 was grounded for a short time after the AA crash at ORD

I think it was after UA 232, not AA 191 that the DC-10's were grounded. Was a long time ago, so you may be right after all.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-27 15:32:07 and read 13251 times.

Quoting flyBTV (Reply 17):
But what about in a fuel exhaustion scenario? That's one of the main situations where I can see all engine and APU generators being inop. Though I suppose a main battery failure concurrently with a fuel exhaustion incident would be pretty unlikely.

The "fuel exhaustion" scenario is a just like the total hydraulic failure (big airplane) and the dual engine (I can't get them restarted) failure senarios, you just hope it's your lucky day and there's even a runway in sight or a nice flat piece of ground/water. You're on your own you, hope there's a runway at the end of your descent. The airplane is engineered to prevent you from getting into any of these senarios but "stuff" happens -- if I make it to a runway with a cliff at the end and don't have any brakes, I'll use the engines for landing gear -- no fuel no fire.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: par13del
Posted 2013-04-27 15:57:46 and read 12977 times.

I would wonder if they are looking at a new battery design, as in why is the battery necessary to operate the APU and vice versa. To most of us a battery can be used to start something, and once started is no longer used, except based on what we have learned in these threads is not the case with the 787, would love to know why such a design was implemented, even if the 787 was not the first. How much charging must a battery get during a six hour flight?

The current issue is that the a/c was grounded due to the battery, so every diversion or despatch failure will be investigated by the general public to see if the battery was involved, and if so, more and more pax will get into the business of trying to identify what type a/c they are flying on when they book or arrive at the airport.

The fixes put in place get the a/c back in service, I would like to believe that Boeing and its subcontractors are looking at designining a new battery and or chemistry ASAP and retrofitting them as soon as possible even if new certification is required, I think this current battery should go the way of the Dodo sooner rather than later.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: twiga
Posted 2013-04-27 18:20:35 and read 11802 times.

Quoting flyBTV (Reply 17):
But what about in a fuel exhaustion scenario? That's one of the main situations where I can see all engine and APU generators being inop. Though I suppose a main battery failure concurrently with a fuel exhaustion incident would be pretty unlikely.

When you are down to the RAT with two engines out (for whatever reason) you are in that 1: 10 million hr event (catostrophic) try multiplying by 50,000 assuming they didn't improve the battery, and your "pretty unlikely" is now qualified.   

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: PC12Fan
Posted 2013-04-27 18:23:57 and read 11786 times.

Quoting ER757 (Reply 19):
I think it was after UA 232, not AA 191 that the DC-10's were grounded. Was a long time ago, so you may be right after all.

IIRC, the grounding was after AA191. Precautionary measures were obviously taken after UA 232, but I don't think there were any "groundings".

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: frmrcapcadet
Posted 2013-04-27 19:22:32 and read 11286 times.

Battery technology is rapidly improving. It is highly likely that Boeing will redo this battery sometime in the next several years. Better, more rugged, more power, lighter, less subject to failure.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: gasman
Posted 2013-04-28 01:55:46 and read 9144 times.

Quoting holzmann (Thread starter):
Say Boeing gets all 787s fixed and service resumes for both current and pending customers BUT battery issues and fires resurface within the next six months: how bad would this scenario be for the 787 and Boeing?

Not a problem. Boeing will simply build yet another box in which to place the current fireproof box which houses the lithium battery that cannot catch fire. 

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: DTW2HYD
Posted 2013-04-28 06:05:54 and read 7389 times.

Quoting 7BOEING7 (Reply 16):
Yes, if you're down to the RAT only, the Main battery supplies power for the electric brakes on rollout because the RAT can't provide power as the airplane slows below about 60 knots (?). If the Main battery were to be inop you would still have the reversers which are very effective to slow the airplane. Depending on conditions (landing speed, weather, etc) with at least 10,000ft of runway you could probably stop before the end. With less you might do a little damage but nothing catastrophic unless it's really not your day (and there's a cliff at the end).

In future they may have to put generators in wheels to pickup from where RAT left off. Similar to regenerative braking in hybrid vehicles.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: ikramerica
Posted 2013-04-28 07:18:39 and read 6859 times.

Quoting gasman (Reply 25):

Correction: "which is not allowed to catch fire." Boeing never claimed it couldn't. FAA was okay with that. Then during grounding FAA made the assinine assertion that no fires were ever allowed on certified aircraft. Why all aircraft in the world weren't immediately grounded after that claim only the FAA knows for sure... And it's why this fix doesn't matter. If any fire of any kind happens on the 787, no matter how mundane, all hell will break loose.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: goosebayguy
Posted 2013-04-28 08:28:50 and read 6167 times.

If any batteries fail and fumes etc emerge then the press are going to be all over this issue. If passenger perception is that the 787 is unsafe they will avoid at all costs. Personally I think Airbus have made the right decision but Boeing have made a very risky choice.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-28 08:33:04 and read 6170 times.

Quoting goosebayguy (Reply 28):
Personally I think Airbus have made the right decision but Boeing have made a very risky choice.


We should not forget that if not for being late, the A350XWB would have been about ready to enter revenue service now and would have had four lithium-ion batteries, so that would be twice the risk in the view of the press and public.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: kanban
Posted 2013-04-28 08:51:43 and read 5947 times.

Quoting par13del (Reply 21):

I would wonder if they are looking at a new battery design, as in why is the battery necessary to operate the APU and vice versa.

I have a suspicion that the APU controller can be operated from a power source other than the APU battery, The only evidence is the ANA wing tip lights flashing when the main battery was off line. Plus Boeing likes redundancy in critical systems.

Quoting ikramerica (Reply 27):
Correction: "which is not allowed to catch fire."

I think the original release was similar to this.... due to the confined sealed space and limited oxygen available, a sustaining fire was improbable. This does not preclude heat damage to a cell, however the new insulation severely limits adjacent cell damage.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: seahawk
Posted 2013-04-28 08:58:12 and read 5874 times.

It is unlikely that we will ever see a similar thermal event. The new containment box is solid and reminds me of other containment designs used for storage of flammable liquids used in industrial production or storage applications.

As the FAA already pointed out, the ETOPS certification could be influenced by battery reliability. And I guess they will look at normal failures and not just thermal events. How this will word out is everyone's guess.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-28 09:11:29 and read 5790 times.

Quoting DTW2HYD (Reply 26):
In future they may have to put generators in wheels to pickup from where RAT left off. Similar to regenerative braking in hybrid vehicles.

A perpetual motion machine--you use the brakes to power the brakes. Seriously, when the RAT stops spinning fast enough to provide electrical power during roll out all that happens is the essential flight instruments lose power and the cockpit goes dark -- no big deal, you're safely on the ground after one of the most harrowing experiences of your life.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: kanban
Posted 2013-04-28 10:39:22 and read 5632 times.

Quoting 7BOEING7 (Reply 32):
Seriously, when the RAT stops spinning fast enough to provide electrical power during roll out all that happens is the essential flight instruments lose power and the cockpit goes dark -- no big deal, you're safely on the ground after one of the most harrowing experiences of your life.

Since the 787 began after I retired, there is a question about the thrust reversers, are the electrically operated? if so if the RAT as your only power source goes can you still activate and deactivate them.. or are the TR's hydraulic?

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: F9animal
Posted 2013-04-28 17:01:51 and read 5267 times.

I think the question by the poster is a great question. If the 787 develops another serious problem, I dont see it fairing well for Boeing. Lets face it, I am sure a few customers have had a conversation regarding what if. As bad as this program has been, another big problem might be what it takes to snap the camels back. I would also expect to see major cancellations from key customers.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: hivue
Posted 2013-04-28 17:59:48 and read 5113 times.

Quoting holzmann (Thread starter):
BUT battery issues and fires resurface within the next six months: how bad would this scenario be for the 787 and Boeing?

So if, say, two more batteries incinerate in the next 50K hours of operation but the containment system works perfectly has the fix been a failure or success?

Quoting goosebayguy (Reply 28):
Personally I think Airbus have made the right decision but Boeing have made a very risky choice.

I think the case has pretty well been made in all these 787 battery threads that Boeing didn't have a choice.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: cornutt
Posted 2013-04-28 19:15:07 and read 4950 times.

Quoting kanban (Reply 33):
Since the 787 began after I retired, there is a question about the thrust reversers, are the electrically operated? if so if the RAT as your only power source goes can you still activate and deactivate them..

Forgive me if I'm overlooking something, but if the RAT is your only power source, the thurst reversers don't matter much, do they?....

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-28 19:18:49 and read 4949 times.

Quoting hivue (Reply 35):
So if, say, two more batteries incinerate in the next 50K hours of operation but the containment system works perfectly has the fix been a failure or success?


I'd say it's a mixed result since the fix is more than just the containment box. Boeing has made modifications to the battery system itself with the idea this would prevent future thermal runaway events.



Quoting cornutt (Reply 36):
Forgive me if I'm overlooking something, but if the RAT is your only power source, the thurst reversers don't matter much, do they?....

We're assuming the airframe was able to perform a safe landing with the RAT as the only power source (admittedly, an event with such a low probability that it's effectively a thought exercise).

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-28 20:58:39 and read 4776 times.

Quoting cornutt (Reply 36):
Quoting cornutt (Reply 36):Forgive me if I'm overlooking something, but if the RAT is your only power source, the thurst reversers don't matter much, do they?....
We're assuming the airframe was able to perform a safe landing with the RAT as the only power source (admittedly, an event with such a low probability that it's effectively a thought exercise).

Actually the only scenario worth discussing that is even close to being realistic is dispatch with an inop APU and loss of all the engine generators--the engines are running and the RAT is supplying electrical power to the essential flight instruments so you can fly the airplane and make a landing. If the MAIN battery dies you don't have any brakes but the reversers work so worst case you run off the end of the runway at 20-30 kts.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: kanban
Posted 2013-04-28 21:20:38 and read 4724 times.

I should have been more specific.. OK all you have is RAT for power, that I guess gives you enough power to activate the thrust reversers to drop the speed to 60 mph or so ... about then the RAT has insufficient wind so you are now powerless.. BUT your engines are running and the TR's are activated.. so when you stop, you immediately start backing up... or is there another power source someplace that will allow you to shut down the engines, shut off the fuel flow etc? I know this is a really worst case scenario but it's stuck in my mind.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: Stitch
Posted 2013-04-28 21:25:38 and read 4708 times.

How likely is a scenario where both engines are under power, but all four engine generators have failed? That seems like one of those "one in a billion" scenarios.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-28 22:24:23 and read 4641 times.

Quoting kanban (Reply 39):
I should have been more specific.. OK all you have is RAT for power, that I guess gives you enough power to activate the thrust reversers to drop the speed to 60 mph or so ... about then the RAT has insufficient wind so you are now powerless.. BUT your engines are running and the TR's are activated.. so when you stop, you immediately start backing up... or is there another power source someplace that will allow you to shut down the engines, shut off the fuel flow etc? I know this is a really worst case scenario but it's stuck in my mind.

Assuming you have lost all the APU/engine generators, you still have full control of the engines and on the ground the engine reversers which are operated by hydraulic power provided by the engines.

Quoting Stitch (Reply 40):
How likely is a scenario where both engines are under power, but all four engine generators have failed? That seems like one of those "one in a billion" scenarios.

I agree, but fuel starvation with a runway within reach is several times that (despite at least two events on record). But assuming that's the case, the RAT would provide instruments until about 60 kts (?) and the Main battery would stop you or at least slow you down a lot. The scenario that uses the battery for brakes is not based on the fuel starvation/runway available scenario but on the RAT electrics/engines operable scenario.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: kanban
Posted 2013-04-28 22:48:18 and read 4597 times.

Thanks.. after three months of outlandish scenarios.. just had to throw one out..      

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: thegeek
Posted 2013-04-28 23:40:14 and read 4476 times.

Main battery out + fuel exhaustion (or other dual engine failure) seems far less outlandish than the prospect of engines still running but 4-6 generators not supplying power.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: twiga
Posted 2013-04-29 00:01:32 and read 4437 times.

Quoting goosebayguy (Reply 28):
If any batteries fail and fumes etc emerge then the press are going to be all over this issue. If passenger perception is that the 787 is unsafe they will avoid at all costs.

With your apparent concerns I don't know how much you have been following these threads. For a fuller answer and somewhat of a summary please check my post #108 on thread "FAA Approves Boeing 787 Battery......". To give you short answers here. Without the root cause known they have done a lot of modifications to the battery cells and charging system to mitigate further failures and hopefully they have fixed it or at least reduced the frequency of failure. The new battery vented containment vessel is likely designed to that 1: 10 million safety metric the same as 2 engines out for a 2 engine aircraft. With this new containment system there will be no fire because its inerted and no fumes or smoke since they will all be vented overboard together with the heat - in the air at a differential pressure of about 9 to 10 psi and on the ground at the differential pressure of reaction. I suspect a burning battery will be a non-event just like a bun burning in a galley oven. And being a non-event with the changes I doubt that it would even be reported and the press and passengers wouldn't know anything about it.
Quoting goosebayguy (Reply 28):
Personally I think Airbus have made the right decision but Boeing have made a very risky choice.

Boeing didn't have much choice in the circumstances short of causing major delays. Their approach is very innovative since ultimate safety from future battery issues is contained. There are always risks in innovation thats how we progress - its sometimes tricky to manage those risks. I bet 2 to 3 years from now Li-ion batteries will be the norm in aircraft, so getting back to Airbus if their airplanes have a 30 year life are they going to be happy with old technology for that long? At some point you have to jump in and get started.
Quoting hivue (Reply 35):
Quoting holzmann (Thread starter):BUT battery issues and fires resurface within the next six months: how bad would this scenario be for the 787 and Boeing?

So if, say, two more batteries incinerate in the next 50K hours of operation but the containment system works perfectly has the fix been a failure or success?

As I mentioned above I suspect a burning battery will be a non-event, and you don't have to worry about the containment vessel working. Lets look at your question from an airlines point of view. If the battery metric was only doubled to 1:100,000 hrs from the mods and changes and an airline had 50 aircraft in its fleet. For about 200,000 fleet hrs/year that would mean 2 battery change outs/ year - not a big deal about 3 hrs/ per a/c. How many times would a similar fleet change a burst tire from landing/ year - probably about the same. So it will be routine maintenance.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: RobK
Posted 2013-04-29 02:01:19 and read 4286 times.

Quoting twiga (Reply 44):
I suspect a burning battery will be a non-event just like a bun burning in a galley oven. And being a non-event with the changes I doubt that it would even be reported and the press and passengers wouldn't know anything about it.
Quoting twiga (Reply 44):
As I mentioned above I suspect a burning battery will be a non-event

        

Not sure if serious or just trolling...

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: hivue
Posted 2013-04-29 08:12:10 and read 3922 times.

Quoting twiga (Reply 44):
If the battery metric was only doubled to 1:100,000 hrs

There were 2 battery overheat events in approximatelyly the first 50,000 hrs, which is 1:25,000. So if that got improved by a factor of 2 by the fix it would be 1:50,000.

Quoting twiga (Reply 44):
that would mean 2 battery change outs/ year

So does the fix significantly reduce the chances of battery failure due to over-discharge where the battery has to be swapped out because it can't be recharged in the airplane from a deep-discharge state?

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-29 09:15:39 and read 3808 times.

Quoting thegeek (Reply 43):
Main battery out + fuel exhaustion (or other dual engine failure) seems far less outlandish than the prospect of engines still running but 4-6 generators not supplying power.

First you're looking a the failure of 4 generators as you can dispatch with the APU inop. Second we're not necessarily saying all 4 engine generators fail but rather an issue with the distribution system. The RAT is installed so that the airplane is still flyable with loss of all normal electrical power and/or all hydraulic power. If loss of both engines was more probable than loss of all electric/hydraulic power we wouldn't need a RAT or we would another engine.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: twiga
Posted 2013-04-29 11:41:08 and read 3631 times.

Quoting RobK (Reply 45):
Quoting twiga (Reply 44):I suspect a burning battery will be a non-event just like a bun burning in a galley oven. And being a non-event with the changes I doubt that it would even be reported and the press and passengers wouldn't know anything about it.Quoting twiga (Reply 44):As I mentioned above I suspect a burning battery will be a non-event.

Not sure if serious or just trolling...

If you had read my referenced post you would know I'm dead serious, and I don't have the inclination or time to mess around with the latter. From the tone of your post, because thats all I can read from the "effort" of 7 words, you appear to be one of these    and if you don't trust the engineering of the new steel containment box, what about the other million things, such as the engines with fire heat and parts rotating at 10,000 rpm that could come flying off and puncture the closely adjacent fuel tanks, all things that have been engineered on the airplane? And you are worried about a little steel containment box? For your types I would suggest the bus or the train.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: thegeek
Posted 2013-04-29 15:46:46 and read 3394 times.

Quoting 7BOEING7 (Reply 47):
First you're looking a the failure of 4 generators as you can dispatch with the APU inop

Which is why I said 4-6 generators. You don't always or even often dispatch with the APU inop.

Quoting 7BOEING7 (Reply 47):
If loss of both engines was more probable than loss of all electric/hydraulic power we wouldn't need a RAT or we would another engine.

Not sure what you mean. RAT saved the Gimli Glider and probably Air Transat. Probably helped in other cases too. Would have been used in BA9 except that windmilling is deemed sufficient in a 747.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-29 16:19:43 and read 3312 times.

Quoting thegeek (Reply 49):
Quoting 7BOEING7 (Reply 47):If loss of both engines was more probable than loss of all electric/hydraulic power we wouldn't need a RAT or we would another engine.
Not sure what you mean. RAT saved the Gimli Glider and probably Air Transat. Probably helped in other cases too. Would have been used in BA9 except that windmilling is deemed sufficient in a 747.

What I was saying was, the probability of a dual engine loss is so low more than two engines is not required. The probability of an electric/hydraulic issue is higher so the RAT is required.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: rcair1
Posted 2013-04-29 16:23:37 and read 3305 times.

Quoting 7BOEING7 (Reply 47):
First you're looking a the failure of 4 generators as you can dispatch with the APU inop. Second we're not necessarily saying all 4 engine generators fail but rather an issue with the distribution system. The RAT is installed so that the airplane is still flyable with loss of all normal electrical power and/or all hydraulic power. If loss of both engines was more probable than loss of all electric/hydraulic power we wouldn't need a RAT or we would another engine.

Are there any cases where all the distribution systems failed, but a RAT saved the day? I don't know of any, but it would be interesting to read about them.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: twiga
Posted 2013-04-29 17:55:40 and read 3244 times.

Quoting hivue (Reply 46):
Quoting twiga (Reply 44):If the battery metric was only doubled to 1:100,000 hrs
There were 2 battery overheat events in approximatelyly the first 50,000 hrs, which is 1:25,000. So if that got improved by a factor of 2 by the fix it would be 1:50,000.

When it comes to statistics technically we are both wrong, because with only two data points you have basically nothing to work from and can not plot a frequency distribution curve to establish any level of confidence - where reasonable estimates can be developed. In my 40 year career as a bridge engineer we wouldn't even consider anything less than at least 25 yrs of records/ data points from stream/river gauges to estimate the 1:50 or 1:100 yr flood and even then we would find other means to confirm numbers. 1:50 yrs means there is a 2% chance in any one year of having a 50 yr flood. And over a long career once in a while the 1:50 yr flood would occur twice over a 2 or 3 yr period - thats statistics, and its possible just possible that something similar occured with the two battery incidents at such close frequency. So lets not get too carried away whether its 1:25k, 1:50k or 1:100k - and improvements to the battery could double, triple or whatever to one of these numbers. The point I was trying to make, if a similar metric applied to a fleet of 50 aircraft, battery change outs due to burning, whether its 2 or 4 batteries per year at 3 hr/per is not a big deal in the general scheme of things. Incidentaly insurance companies work from millions of data points and have a level of confidence probably above 99% hence they never loose money.

Quoting hivue (Reply 46):
Quoting twiga (Reply 44):that would mean 2 battery change outs/ year
So does the fix significantly reduce the chances of battery failure due to over-discharge where the battery has to be swapped out because it can't be recharged in the airplane from a deep-discharge state?

No I was refering to burning batteries. This is a different issue they had by what 200 or more battery swap outs over a year from "deep discharge", because maintenance people took too long or whatever. I think somebody posted something about this before. And suggested when they did the fix they might set two low voltage shut offs with a narrow margine between them. The lowest shut off (1) - battery removed from airplane for special recharging for "deep discharge" (as before), and shut off (2) - at a slightly higher safer voltage for battery rechargeable on aircraft. Apparently there is a safety issue with these batteries when charging from "deep discharge". Perhaps this is as easy as a software change in the charger - I don't know.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: rcair1
Posted 2013-04-29 18:33:30 and read 3192 times.

Quoting 7BOEING7 (Reply 47):
First you're looking a the failure of 4 generators as you can dispatch with the APU inop.

Not really - APU inop means that failure has happened recently - so you have to look at it as 4 generators + APU.

Quoting 7BOEING7 (Reply 50):
What I was saying was, the probability of a dual engine loss is so low more than two engines is not required. The probability of an electric/hydraulic issue is higher so the RAT is required.

I'm not sure that is true. Not sure it is not, but just not sure it is.

I think the key is that - even with 2 engines out - you are flying and in a craft that is fundamentally still flyable, provided you have hydraulics and/or minimal electrics. The rat is there because it is needed to provide that - to maintain a controllable a/c when other power sources have failed. Not because the hydraulic/electrical systems have failed. I think if you have lost all your hydraulics, the rat will not help.

As I asked before - do we have any cases where the a/c engines remained operable, but the hydraulic systems all failed, and the Rat was still able to provide hydraulic. (or electric). In other words, does they Rat have an independent hydraulic system - or will it also fail when all hydraulic systems are gone.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: thegeek
Posted 2013-04-29 19:57:10 and read 3096 times.

Quoting rcair1 (Reply 53):
As I asked before - do we have any cases where the a/c engines remained operable, but the hydraulic systems all failed, and the Rat was still able to provide hydraulic. (or electric). In other words, does they Rat have an independent hydraulic system - or will it also fail when all hydraulic systems are gone.

My understanding is that the RAT will generally power only one of the normal hydraulic circuits. If that circuit is gone, it is curtains.

I echo your sentiments - a RAT has never saved the day when any engines are operable to my knowledge.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-29 20:31:33 and read 3059 times.

Quoting rcair1 (Reply 53):
I think the key is that - even with 2 engines out - you are flying and in a craft that is fundamentally still flyable, provided you have hydraulics and/or minimal electrics.

True, it is flyable until it hits the ground/water. Both the 767 and 330 that happened to find a runway at the end of their descent were near miracles. Other fuel starvation events in history haven't ended so happily. Since the "Canadian" events, checklists and other system improvements have decreased the possibly of fuel starvation. Bird strikes weren't supposed to cause engines to fail but they did and fortunately there was a river available.

Quoting rcair1 (Reply 53):
The rat is there because it is needed to provide that - to maintain a controllable a/c when other power sources have failed. Not because the hydraulic/electrical systems have failed.

The RAT is there for multiple reasons, some of which are more likely than a non-recoverable dual engine failure. If your engines quit the Main battery provides power to the essential instruments until the RAT takes over -- the engines continue to provide the hydraulics (if they're still on the wing) until just prior to landing.

Two events that I believe have a higher probability than a non-recoverable dual engine failure are:

If you lose all hydraulic pressure the RAT automatically drops and provides hydraulics to the flight controls powered by the center system.

If you lose electric power to the essential instruments the RAT automatically drops and takes over for the Main battery powering the essential instruments.

Quoting rcair1 (Reply 53):
I think if you have lost all your hydraulics, the rat will not help.

If you just lose pressure the RAT will work as long as you haven't lost all your center system hydraulic fluid.

Quoting rcair1 (Reply 53):
As I asked before - do we have any cases where the a/c engines remained operable, but the hydraulic systems all failed, and the Rat was still able to provide hydraulic. (or electric). In other words, does they Rat have an independent hydraulic system - or will it also fail when all hydraulic systems are gone.

No cases I can think of for either the 777 or 787 and as I said above as long as you have fluid in the center system you'll have hydraulic power to the center system flight controls. Note, however, that should you lose all hydraulic power (L/R/C systems inop and C system fluid gone) you still have the stabilizer and two spoilers on each wing that are electrically powered.

[Edited 2013-04-29 20:37:20]

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 7BOEING7
Posted 2013-04-29 20:51:13 and read 3029 times.

Quoting thegeek (Reply 54):

My understanding is that the RAT will generally power only one of the normal hydraulic circuits. If that circuit is gone, it is curtains.

The RAT powers C system flight controls. Curtains?? not yet -- stabilizer and 2 spoilers on each wing have electric backup.

Quoting thegeek (Reply 54):
I echo your sentiments - a RAT has never saved the day when any engines are operable to my knowledge.

And let's hope it never has to but I'm sure it will do a fine job when asked. I don't think it's ever saved the day when any engines were inoperable either. I'm not sure it's ever had to auto deploy for either airplane in service.

[Edited 2013-04-29 20:52:28]

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: thegeek
Posted 2013-04-30 01:15:59 and read 2919 times.

Quoting 7BOEING7 (Reply 56):
Curtains?? not yet -- stabilizer and 2 spoilers on each wing have electric backup.

I guess I was really thinking about a 767 or similar with no electric backup.

Quoting 7BOEING7 (Reply 56):
I don't think it's ever saved the day when any engines were inoperable either

Gimli Glider. I presume Air Transat too.

Topic: RE: If 787 'fix' Is Short-lived: How Bad For Boeing?
Username: 777ER
Posted 2013-04-30 06:41:11 and read 2756 times.

Thread has gone off topic so will now be locked

777ER
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