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TOV Forums > General Talk > > Re: The most worry thing about the Boeing 787 is the lithium batteries!

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RolledaNsx
Profile for RolledaNsx
The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 14:55
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Per FAA

They overheat, then leak, finally catch fire, that the firemen can't put it out.

The batteries are made by the same company who makes Honda's lithium batteries.

I think Boeing drop the ball on the cooling of the batteries like how they screwed up everything else with the 787(to raise the profit margen of each plane they spread the manufature of key parts around to other companies(lowest bidder) but they lost control and now its biting them in there ass!!!!

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 15:37
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And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....


owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 15:45
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RolledaNsx wrote:
Per FAA

They overheat, then leak, finally catch fire, that the firemen can't put it out.

The batteries are made by the same company who makes Honda's lithium batteries.

I think Boeing drop the ball on the cooling of the batteries like how they screwed up everything else with the 787(to raise the profit margen of each plane they spread the manufature of key parts around to other companies(lowest bidder) but they lost control and now its biting them in there ass!!!!



Rolled, most of it is sensationalism.

1) Boeing did not screw up everything with the 787. It is completely new technology on this scale, and thus there are going to be teething problems.

In fact, there are teething problems with almost ANY new entry into service (EIS) with any aircraft model, even if they use old technology. Take a look at the Airbus A380 for an example of an aircraft that really broke no new technical ground, but still had a world of problems at the beginning. In fact, nothing on that plane was more than scaled up A330/747 technology. It was also grounded several times in its early service career and STILL has some system design flaws that I think are bad. They have had to strengthen and modify wings more than once, and had a string of early uncontained engine failures.

The 787 completely rewrites the book on transport category design, construction, implementation, systems application/integration and passenger comfort. It pushes engine technology, materials technology, design technology, manufacturing technology and service/repair technology. Unlike any plane before it to go into commercial passenger service, this airplane has moved technology on par with the original DeHavilland Comet.

Boeing did not pursue risk sharing as a means to increase profit on each unit. They did it as a means to insulate themselves from financial oblivion in the event the aircraft wasn't successful. Yes, it has had a string of hurdles, but then again, such a project of responsibility sharing has never been taken on with this scale in aircraft design either. Boeing has openly admitted that the sub-assembly responsibility concept (whereby vendors design and deliver components to exact specification) didn't work as cleanly as they had planned. Let that be a lesson to Honda in the near future. However, Boeing is adapting, changing, modifying and altering the way they do it to make the concept work. With as successful as the CAD/CAM process was on the 777, there was no logical reason to believe it couldn't naturally be extended to the 787 process successfully.

The issues that need to be worked out with the 787 (which they will work out) are a big part of the reason the narrowbody Y1 project was not launched to replace the 737 with an airplane similar in technology to the 787, and instead a revision of the 737 was marketed.

There have been very few aircraft that have ever come close to pushing the technological envelope the way the 787 has, and virtually none of them were used for commercial aviation.

2)As for the batteries:

This is among the first use of Li-Ion batteries in commercial aviation for an actual systems implementation. Li-Ion batteries are a known safety concern on aircraft due to their instability throughout the thermal operating envelope of the aircraft (where temps of batteries may go from nearly -50*C to nearly 100*C+ in less than 10-15 minutes.

Li-Ion batteries are thought to be responsible for a 747 crash in the Middle East because it was the only source of fire that could be explained given the circumstances. And those were just batteries on board for transport. It seems that somehow they got loose, got hot and the ensuing fire took the plane down.

However, I do not think Li-Ion batteries will not continue to be improved for aircraft use. I think they have some refinements that need to be worked out, but over time, both systems design and fire fighting/fire suppression design will be modified to deal with it. At this point in time, ARFF systems used water based foam, and we know that doesn't work with lithium fires. Over time, you will probably see them start to carry something that does work with lithium simply because of the proliferation of Li-Ion batteries.

For the record, of all of the issues with the 787, the only one that has been majorly concerning is the battery fire with the APU. The rest of them have largely been hyped for media sensationalism, and nobody is considering the fact that flight crews are being especially cautious with returning for landing, because it simply isn't worth the risk to continue and everybody is at a heightened sense of alert.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 15:49
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Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.

xBeastx
Profile for xBeastx
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 16:36
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owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.


It could drive into a lake full of swimming people.

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 17:01
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owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??

RolledaNsx
Profile for RolledaNsx
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 17:36
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To compete against Airbus they built the 787 the Airbus way.

Instead of building the complete aircraft up in the traditional way(in house/one location).Boeing assigned its global subcontractors to do more assembly/testing themselves and deliver completed subassemblies to Boeing for final assembly.This approach was intended to result in a leaner and simpler assembly line and lower inventories and less employees.

On paper that system is great but what Airbus learned from doing it for 30 years it doesn't always work(one subcontractor can kill/delay the whole project /one strike or hard to find/defect part) but they can't change because of political reasons(EU).

CarPhreakD
Profile for CarPhreakD
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 18:12
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RolledaNsx wrote:
To compete against Airbus they built the 787 the Airbus way.

Instead of building the complete aircraft up in the traditional way(in house/one location).Boeing assigned its global subcontractors to do more assembly/testing themselves and deliver completed subassemblies to Boeing for final assembly.This approach was intended to result in a leaner and simpler assembly line and lower inventories and less employees.

On paper that system is great but what Airbus learned from doing it for 30 years it doesn't always work(one subcontractor can kill/delay the whole project /one strike or hard to find/defect part) but they can't change because of political reasons(EU).



The issue looks to be a design fault, not a supplier fault.

CarPhreakD
Profile for CarPhreakD
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 18:14
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Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??



Volts don't drop out of the sky, and they don't pose any more of a risk than any other car out there. It took who knows how long for Ferrari to start recalling cars due to a flammable epoxy, and those were fires that happened under normal usage, not even the crash conditions and weeks-long storage that the Volt was placed under.

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 21:23
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CarPhreakD wrote:
RolledaNsx wrote:
To compete against Airbus they built the 787 the Airbus way.

Instead of building the complete aircraft up in the traditional way(in house/one location).Boeing assigned its global subcontractors to do more assembly/testing themselves and deliver completed subassemblies to Boeing for final assembly.This approach was intended to result in a leaner and simpler assembly line and lower inventories and less employees.

On paper that system is great but what Airbus learned from doing it for 30 years it doesn't always work(one subcontractor can kill/delay the whole project /one strike or hard to find/defect part) but they can't change because of political reasons(EU).



The issue looks to be a design fault, not a supplier fault.



Most of the scuttlebutt seems to be pointing to the software that controls the batteries. From what I have read the charging process is pretty intricate, and if there is a problem on the software end you can get to a point to where you cannot stop the batteries from going up in flames.

Fan Koni
Profile for Fan Koni
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 21:28
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It probably is a design thing, but I guess that is not due to the initial newness of the components but the cost cutting down the road of development.
Specially since the plane is late they will have to do more for less.
Not only in the automotive world, generally most suppliers offer different quality levels depending on their customer. Bigger customers mean more pain.

This supplier bad mouthing is really annoying.

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 21:30
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CarPhreakD wrote:
Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??



Volts don't drop out of the sky, and they don't pose any more of a risk than any other car out there. It took who knows how long for Ferrari to start recalling cars due to a flammable epoxy, and those were fires that happened under normal usage, not even the crash conditions and weeks-long storage that the Volt was placed under.




I haven't seen too many Accords that three weeks after an accident turn themselves into a pile of melted steel and aluminum like the Volts did. The point is that Lion batteries are being used and there are still a lot of issues with them, and they have not been thoroughly tested enough. If so, the Volts wouldn't have turned themselves into a voltive candle. And because the prancing horses decide to spontaneously combust does not mean that it is right for Volts to self ignite. Both needed to be recalled. (And no one knew or even imagined that the Volts would or could do what they ended up doing.... How does anyone know that they might not do so after so many miles or hours of usage?)

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 22:06
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Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??



Don't be ridiculous.

The cold hard reality is that nothing makes headlines and makes government oversight look bad (if there are any lapses) like a plane crash. It is debatable that even gun tragedies generate the same media storm as consistently as plane crashes do. Not to mention that it would take a lot of Volt crashes to equal the damage of 1 787 crash. It doesn't make the loss any more bearable, it is simply the reality of the way life is.

When you kill several hundred people in a singular event it looks bad because the media sensationalizes the hell out of it. Look at how much media coverage the 787 is getting right now, even though nothing has even happened yet. They are even reporting negatively about things that are routine occurrences with transport category aircraft (such as the non-structural outer layer of windscreen glass cracking; which happens on every airliner in existence on an almost daily basis).

Also, let's be realistic. Nobody died in the Volt. The only way the battery packs went up in flames were AFTER the car had been in an accident, AFTER it had been taken to the junk yard, and AFTER it had been sitting with the battery pack exposed for a period of time. There was no danger to the people in the cars at any time. By your logic, we should take care of Li-Ion cell phone batteries right now too because there were a few that went up while the device was being charged. We wouldn't want to burn anyone would we?

Or you could outlaw the batteries altogether. That is also an option.

The other major component about an airplane that is different is that once that fire starts, if you aren't on the ground, your ass has nowhere to go to escape it. If a Volt goes up, worst case scenario is you bail rather than fight the fire. The odds of it going up so quickly you can't get out are not very probable. Even in the case of the 787 battery fire, it was going for something like 6-10 minutes before any of the ground personnel even noticed it. Had they been out over the Pacific (where they were headed), the outcome likely would have been far different. If they were even at cruising altitude over the Continental US, the outcome still could have been catastrophic (note the Valujet accident for how quickly it comes apart once the fire reaches a certain point).

Fire on an airplane is like fire on a boat. It is enemy number one as far as mechanical deficiencies go.

Also, as to the snideness of your comment, I will give you a safety perspective:

The cold hard reality of life is that no matter how hard you try, you will NEVER eliminate 100% loss of life. It doesn't make it acceptable, and we always work toward zero to the best of our ability, but at some point there is a factor that you can't stop.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 22:11
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RolledaNsx wrote:
To compete against Airbus they built the 787 the Airbus way.

Instead of building the complete aircraft up in the traditional way(in house/one location).Boeing assigned its global subcontractors to do more assembly/testing themselves and deliver completed subassemblies to Boeing for final assembly.This approach was intended to result in a leaner and simpler assembly line and lower inventories and less employees.

On paper that system is great but what Airbus learned from doing it for 30 years it doesn't always work(one subcontractor can kill/delay the whole project /one strike or hard to find/defect part) but they can't change because of political reasons(EU).



Their system is actually quite different than the Airbus system.

They had more risk sharing, but that is sort of where the similarities end.

CarPhreakD
Profile for CarPhreakD
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-18-2013 23:33
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Fan Koni wrote:
It probably is a design thing, but I guess that is not due to the initial newness of the components but the cost cutting down the road of development.
Specially since the plane is late they will have to do more for less.
Not only in the automotive world, generally most suppliers offer different quality levels depending on their customer. Bigger customers mean more pain.

This supplier bad mouthing is really annoying.



When I mean a design thing, I meant on Boeing's end. They just specify components out to suppliers, they don't do the development work.

Suppliers do not offer different quality levels- tolerances and resulting scrap rates are determined by the buying company's quality team, usually based on a statistical requirement (ppk and cpk > 1.3 or so). In this competitive environment, they will get dropped if they don't meet the company's internal quality targets.

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 00:02
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owequitit wrote:
Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??



Don't be ridiculous.

The cold hard reality is that nothing makes headlines and makes government oversight look bad (if there are any lapses) like a plane crash. It is debatable that even gun tragedies generate the same media storm as consistently as plane crashes do. Not to mention that it would take a lot of Volt crashes to equal the damage of 1 787 crash. It doesn't make the loss any more bearable, it is simply the reality of the way life is.

When you kill several hundred people in a singular event it looks bad because the media sensationalizes the hell out of it. Look at how much media coverage the 787 is getting right now, even though nothing has even happened yet. They are even reporting negatively about things that are routine occurrences with transport category aircraft (such as the non-structural outer layer of windscreen glass cracking; which happens on every airliner in existence on an almost daily basis).

Also, let's be realistic. Nobody died in the Volt. The only way the battery packs went up in flames were AFTER the car had been in an accident, AFTER it had been taken to the junk yard, and AFTER it had been sitting with the battery pack exposed for a period of time. There was no danger to the people in the cars at any time. By your logic, we should take care of Li-Ion cell phone batteries right now too because there were a few that went up while the device was being charged. We wouldn't want to burn anyone would we?

Or you could outlaw the batteries altogether. That is also an option.

The other major component about an airplane that is different is that once that fire starts, if you aren't on the ground, your ass has nowhere to go to escape it. If a Volt goes up, worst case scenario is you bail rather than fight the fire. The odds of it going up so quickly you can't get out are not very probable. Even in the case of the 787 battery fire, it was going for something like 6-10 minutes before any of the ground personnel even noticed it. Had they been out over the Pacific (where they were headed), the outcome likely would have been far different. If they were even at cruising altitude over the Continental US, the outcome still could have been catastrophic (note the Valujet accident for how quickly it comes apart once the fire reaches a certain point).

Fire on an airplane is like fire on a boat. It is enemy number one as far as mechanical deficiencies go.

Also, as to the snideness of your comment, I will give you a safety perspective:

The cold hard reality of life is that no matter how hard you try, you will NEVER eliminate 100% loss of life. It doesn't make it acceptable, and we always work toward zero to the best of our ability, but at some point there is a factor that you can't stop.




Guess you haven't seen any of the videos where a dell self immolates on a table top. Not being snide but the point is there are a lot of issues with Lion's that have not been figured out yet, and the larger the battery the higher the risk of having serious injury, and the Volt has a large enough battery to cause serious burns in a short time, which is the point you seem to be missing. I could care less what the media chooses to make issue of, but are more concerned that Lion's are being widely used as a panacea to the inherant power limitations of other types of batteries.

And once again, if the Volt can catch fire three weeks after a crash when GM's OWN engineers thought they had disabled the battery packs and made the cars safe how do you know that there might not be some other flaws that pop up later on after more accumlated milage?

And you have never answered the question on why there has not been a recall or a final determination on what caused the Volt fires and how to prevent them in the future.

Fan Koni
Profile for Fan Koni
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 04:09
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CarPhreakD wrote:
Fan Koni wrote:
It probably is a design thing, but I guess that is not due to the initial newness of the components but the cost cutting down the road of development.
Specially since the plane is late they will have to do more for less.
Not only in the automotive world, generally most suppliers offer different quality levels depending on their customer. Bigger customers mean more pain.

This supplier bad mouthing is really annoying.



When I mean a design thing, I meant on Boeing's end. They just specify components out to suppliers, they don't do the development work.

Suppliers do not offer different quality levels- tolerances and resulting scrap rates are determined by the buying company's quality team, usually based on a statistical requirement (ppk and cpk > 1.3 or so). In this competitive environment, they will get dropped if they don't meet the company's internal quality targets.


I meant design specs too.

I think since this is a new system - likely working among other new systems - I expect the specs not to be that detailed from Boeing in the first round. They don't make battery systems and the connected systems after all.
So then the suppliers come up with suggestions; in the then ongoing detailing iterations the nitpicking starts and costs of components "reviewed"...

Just because ppk and cpk are met doesn't mean they are defined well! Maybe Boeing doesn't fully understand all processes happening around and in the battery system yet?

And yes Automotive suppliers do offer different levels, especially on systems/modules e.g. version A has components with cheaper materials than version B. A may be good & cheap enough for VW but not for MB.

superchg2
Profile for superchg2
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 04:26
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Fan Koni wrote:
Maybe Boeing doesn't fully understand all processes happening around and in the battery system yet?


Kind of a scary thought!

RolledaNsx
Profile for RolledaNsx
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 11:32
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That happens when you do something first,there is no history to start from.To get all the power from the engines for thrust,they made everything electric....and it looks like the battery couldn't handle it....back to research and development.
owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 18:11
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Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
owequitit wrote:
Mr. Taggart wrote:
And we will hear from TonyE in 3..2...1....


Why is it that the FAA sees problems with runaway ignition in planes but there isn't much concern about the same thing happeing in a Chevy Volt....




A Chevy Volt isn't going to kill 250 people at a pop.




So 4-5 at a pop is ok??



Don't be ridiculous.

The cold hard reality is that nothing makes headlines and makes government oversight look bad (if there are any lapses) like a plane crash. It is debatable that even gun tragedies generate the same media storm as consistently as plane crashes do. Not to mention that it would take a lot of Volt crashes to equal the damage of 1 787 crash. It doesn't make the loss any more bearable, it is simply the reality of the way life is.

When you kill several hundred people in a singular event it looks bad because the media sensationalizes the hell out of it. Look at how much media coverage the 787 is getting right now, even though nothing has even happened yet. They are even reporting negatively about things that are routine occurrences with transport category aircraft (such as the non-structural outer layer of windscreen glass cracking; which happens on every airliner in existence on an almost daily basis).

Also, let's be realistic. Nobody died in the Volt. The only way the battery packs went up in flames were AFTER the car had been in an accident, AFTER it had been taken to the junk yard, and AFTER it had been sitting with the battery pack exposed for a period of time. There was no danger to the people in the cars at any time. By your logic, we should take care of Li-Ion cell phone batteries right now too because there were a few that went up while the device was being charged. We wouldn't want to burn anyone would we?

Or you could outlaw the batteries altogether. That is also an option.

The other major component about an airplane that is different is that once that fire starts, if you aren't on the ground, your ass has nowhere to go to escape it. If a Volt goes up, worst case scenario is you bail rather than fight the fire. The odds of it going up so quickly you can't get out are not very probable. Even in the case of the 787 battery fire, it was going for something like 6-10 minutes before any of the ground personnel even noticed it. Had they been out over the Pacific (where they were headed), the outcome likely would have been far different. If they were even at cruising altitude over the Continental US, the outcome still could have been catastrophic (note the Valujet accident for how quickly it comes apart once the fire reaches a certain point).

Fire on an airplane is like fire on a boat. It is enemy number one as far as mechanical deficiencies go.

Also, as to the snideness of your comment, I will give you a safety perspective:

The cold hard reality of life is that no matter how hard you try, you will NEVER eliminate 100% loss of life. It doesn't make it acceptable, and we always work toward zero to the best of our ability, but at some point there is a factor that you can't stop.




Guess you haven't seen any of the videos where a dell self immolates on a table top. Not being snide but the point is there are a lot of issues with Lion's that have not been figured out yet, and the larger the battery the higher the risk of having serious injury, and the Volt has a large enough battery to cause serious burns in a short time, which is the point you seem to be missing. I could care less what the media chooses to make issue of, but are more concerned that Lion's are being widely used as a panacea to the inherant power limitations of other types of batteries.

And once again, if the Volt can catch fire three weeks after a crash when GM's OWN engineers thought they had disabled the battery packs and made the cars safe how do you know that there might not be some other flaws that pop up later on after more accumlated milage?

And you have never answered the question on why there has not been a recall or a final determination on what caused the Volt fires and how to prevent them in the future.



Yeah, I have seen it. Short of outlawing them, they are already being used. Focusing on how they shouldn't be there isn't going to solve the problem of getting them to work now that they ARE there.

Mr. Taggart
Profile for Mr. Taggart
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 19:01
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So maybe they shouldn't be there in the first place....But that would kill the greenies push to say that battery powered things are the wave of the future as well as being cost effective and as safe as the technology that it is replacing.


owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 20:34
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Mr. Taggart wrote:
So maybe they shouldn't be there in the first place....But that would kill the greenies push to say that battery powered things are the wave of the future as well as being cost effective and as safe as the technology that it is replacing.




Actually, Boeing had a lot of good reasons to use batteries other than just to appease the greenies.

Unlike with hybrid cars, the fuel savings technology used in an airplane has a direct and VERY measurable economic benefit. When the typical aircraft the size of the Dreamliner is burning on the order of 5-6 tons of fuel per hour during cruise, the cash savings from even a 1-2% improvment can mean millions of dollars per aircraft, per year worth of savings. The fact that the 787 reduced the average fuel burn compared to an airplane of approximately the same size, like a 767 by 20% or more is sort of a big deal.

That said, I have started looking at the 787's electrical system, because I am not fully convince the Li-Ion battery problem has anything to do with their transition away from traditional aircraft systems. The APU on all aircraft has a battery, and that battery is used as A) electrical storage unit and B) a buffer against surges and spikes. The fact that the APU battery is having a problem is not necessarily indicative of a poor design on the aircraft electrical system.

There is nothing unusual in the 787's electrical system that should cause this problem outside of the APU's battery. My guess would be that it is simply improper programming of the APU battery system.

However, the rest of the systems conversion to electrical from pneumatic is pretty substantial, and has a LOT of benefits to the airlines and the passengers.

First, the availability of bleed air is not dependent on engine power setting. With a minimum volume required to maintain cabin pressure, and with a minimum temperature and volume required to maintain de-ice during cold weather operations, the engines ended up operating at a higher than required power setting in many situations. Especially in cold weather descents, power would have to be kept up in order to keep the wings clear of contamination, and this would often lead to descents with the spoilers out, which is a tremendous waste of fuel. Now, with the electrically driven de-ice systems, the temperatures can be maintained as long as there is sufficient RPM on the engines (gas turbines idle at about 70% of redline, so it shouldn't be a problem once the engine is running). That removes the requirement to keep RPM up to ensure a sufficient supply of hot air from the engine's compressor section (which then has to lose a lot of temp as it is piped through ducts, pipes and manifolds).

It also allows a more comfortable ride for the pax because you don't get the occasional pressure surging in the cabin pressurization system when the engines are throttled, or other bleed demands are added, and they have much more finite control over cabin temps, humidity etc.

Couple that with the weight savings of the 787's systems, and the need to not oversize the engines quite as much in order to get the desired performance, and there are more advantages to the systems design than disadvantages.

As for the Li-Ion batteries, it sounds like they are overcharging due to faulty control logic. Not to be a dick, but NiCAD and NiMH batteries will also potentially catch fire if they are overcharged enough, and in fact, any NiCAD battery installed in a transport category airplane is required to have a seperate temperature gauge for each individual battery to ensure they don't get too hot.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 20:41
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owequitit wrote:
Mr. Taggart wrote:
So maybe they shouldn't be there in the first place....But that would kill the greenies push to say that battery powered things are the wave of the future as well as being cost effective and as safe as the technology that it is replacing.




Actually, Boeing had a lot of good reasons to use batteries other than just to appease the greenies.

Unlike with hybrid cars, the fuel savings technology used in an airplane has a direct and VERY measurable economic benefit. When the typical aircraft the size of the Dreamliner is burning on the order of 5-6 tons of fuel per hour during cruise, the cash savings from even a 1-2% improvment can mean millions of dollars per aircraft, per year worth of savings. The fact that the 787 reduced the average fuel burn compared to an airplane of approximately the same size, like a 767 by 20% or more is sort of a big deal.

That said, I have started looking at the 787's electrical system, because I am not fully convince the Li-Ion battery problem has anything to do with their transition away from traditional aircraft systems. The APU on all aircraft has a battery, and that battery is used as A) electrical storage unit and B) a buffer against surges and spikes. The fact that the APU battery is having a problem is not necessarily indicative of a poor design on the aircraft electrical system.

There is nothing unusual in the 787's electrical system that should cause this problem outside of the APU's battery. My guess would be that it is simply improper programming of the APU battery system.

However, the rest of the systems conversion to electrical from pneumatic is pretty substantial, and has a LOT of benefits to the airlines and the passengers.

First, the availability of bleed air is not dependent on engine power setting. With a minimum volume required to maintain cabin pressure, and with a minimum temperature and volume required to maintain de-ice during cold weather operations, the engines ended up operating at a higher than required power setting in many situations. Especially in cold weather descents, power would have to be kept up in order to keep the wings clear of contamination, and this would often lead to descents with the spoilers out, which is a tremendous waste of fuel. Now, with the electrically driven de-ice systems, the temperatures can be maintained as long as there is sufficient RPM on the engines (gas turbines idle at about 70% of redline, so it shouldn't be a problem once the engine is running). That removes the requirement to keep RPM up to ensure a sufficient supply of hot air from the engine's compressor section (which then has to lose a lot of temp as it is piped through ducts, pipes and manifolds).

It also allows a more comfortable ride for the pax because you don't get the occasional pressure surging in the cabin pressurization system when the engines are throttled, or other bleed demands are added, and they have much more finite control over cabin temps, humidity etc.

Couple that with the weight savings of the 787's systems, and the need to not oversize the engines quite as much in order to get the desired performance, and there are more advantages to the systems design than disadvantages.

As for the Li-Ion batteries, it sounds like they are overcharging due to faulty control logic. Not to be a dick, but NiCAD and NiMH batteries will also potentially catch fire if they are overcharged enough, and in fact, any NiCAD battery installed in a transport category airplane is required to have a seperate temperature gauge for each individual battery to ensure they don't get too hot.



I should say electrical systems, not necessarily batteries. But as previously posted, ALL overcharged batteries carry risk, and the Li-Ions are not the first ones to cause overheating fires.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 20:49
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http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_06/article_04_3.html
owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 20:53
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CarPhreakD wrote:
Fan Koni wrote:
It probably is a design thing, but I guess that is not due to the initial newness of the components but the cost cutting down the road of development.
Specially since the plane is late they will have to do more for less.
Not only in the automotive world, generally most suppliers offer different quality levels depending on their customer. Bigger customers mean more pain.

This supplier bad mouthing is really annoying.



When I mean a design thing, I meant on Boeing's end. They just specify components out to suppliers, they don't do the development work.

Suppliers do not offer different quality levels- tolerances and resulting scrap rates are determined by the buying company's quality team, usually based on a statistical requirement (ppk and cpk > 1.3 or so). In this competitive environment, they will get dropped if they don't meet the company's internal quality targets.



The system doesn't work quite that way in the case of the 787. The risk sharing partners (the 787 is actually "owned" by several aerospace companies, but takes the Boeing name) were responsible for a lot of the systems design. Boeing tried to decentralize the design process, and only worked to make sure that the various components and systems would interface with each other. I am pretty sure they did not dictate anything down to the Nth degree, which is why there have been so many problems with components not working the way they were supposed to.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 20:58
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RolledaNsx wrote:
That happens when you do something first,there is no history to start from.To get all the power from the engines for thrust,they made everything electric....and it looks like the battery couldn't handle it....back to research and development.


The system does not run on the battery when the aircraft is engines on. The starter/generators run everything and the battery is merely a bystander at that point. The APU battery is there specifically to start the APU, and to keep it running regardless what the other systems are doing. However, again, once the APU is running, its generators take over the load, and it is not put on the battery.

Most likely what is happening here is that the battery is being overcharged after it is taken offline for an APU start. Rather than stop charging it, the control logic probably run too long, overheating the battery.

I hope you guys understand that aircraft systems are completely different than car systems...

RolledaNsx
Profile for RolledaNsx
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-19-2013 22:31
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My pay stub this week says Premium AEROTEC.

We all know it is being overcharged,even the media knows that.

Why don't you explain why this aircraft being 100% electric is different from any other aircraft.

Also explain why they have to fix the Li-ion battery problem and not switch to another type of battery.

hint.... weight,range,contract

CarPhreakD
Profile for CarPhreakD
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-20-2013 00:46
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Fan Koni wrote:
CarPhreakD wrote:
Fan Koni wrote:
It probably is a design thing, but I guess that is not due to the initial newness of the components but the cost cutting down the road of development.
Specially since the plane is late they will have to do more for less.
Not only in the automotive world, generally most suppliers offer different quality levels depending on their customer. Bigger customers mean more pain.

This supplier bad mouthing is really annoying.



When I mean a design thing, I meant on Boeing's end. They just specify components out to suppliers, they don't do the development work.

Suppliers do not offer different quality levels- tolerances and resulting scrap rates are determined by the buying company's quality team, usually based on a statistical requirement (ppk and cpk > 1.3 or so). In this competitive environment, they will get dropped if they don't meet the company's internal quality targets.


I meant design specs too.

I think since this is a new system - likely working among other new systems - I expect the specs not to be that detailed from Boeing in the first round. They don't make battery systems and the connected systems after all.
So then the suppliers come up with suggestions; in the then ongoing detailing iterations the nitpicking starts and costs of components "reviewed"...

Just because ppk and cpk are met doesn't mean they are defined well! Maybe Boeing doesn't fully understand all processes happening around and in the battery system yet?

And yes Automotive suppliers do offer different levels, especially on systems/modules e.g. version A has components with cheaper materials than version B. A may be good & cheap enough for VW but not for MB.



The first one is believable, the second one is not (unless things work different outside of NA- I can believe suppliers in Mexico or Malaysia doing something like this)). "Version A" vs. "Version B" would be something that the automaker would spec. You wouldn't use forged pistons in a Civic, but it doesn't mean that the cast pistons used are on any "less" of a level. Nobody ships out faulty or low quality products by choice.

daddywags
Profile for daddywags
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-20-2013 01:34
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Here are some facts most people don't seem aware of. There is more than one kind of Lithium-ion battery. Chemistry varies. From GreenCar Rpeort on Friday:

"The cells in the 787, from Japanese company GS Yuasa, use a cobalt oxide (CoO2) chemistry, just as mobile-phone and laptop batteries do. That chemistry has the highest energy content, but it is also the most susceptible to overheating that can produce "thermal events" (which is to say, fires). Only one electric car has been built in volume using CoO2 cells, and that's the Tesla Roadster. Only 2,500 of those cars will ever exist. The Chevrolet Volt range-extended electric car, on the other hand, uses LG Chem prismatic cells with manganese spinel (LiMn2O4) cathodes. While chemistries based on manganese, nickel, and other metals carry less energy per volume, they are widely viewed as less susceptible to overheating and fires."

Further, the Volt fire referred to was the result of a crash test by the NHTSA, after which the car was rotated through 360 degrees and left to sit. The fire occurred 3 weeks later, after the NHTSA mechanics did nothing to secure the batteries.

Boeing's problems are unrelated to the batteries used in the Volt, and Volt owners have not assumed the same risk that Boeing put in its 787.

owequitit
Profile for owequitit
Re: The most worry thing about the Boeing 787 is the lithium batteries!    (Score: 1, Normal) 01-20-2013 02:17
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RolledaNsx wrote:
My pay stub this week says Premium AEROTEC.

We all know it is being overcharged,even the media knows that.

Why don't you explain why this aircraft being 100% electric is different from any other aircraft.

Also explain why they have to fix the Li-ion battery problem and not switch to another type of battery.

hint.... weight,range,contract



This week only? You do realize that I have been in aviation for 15 years and my background is aerodynamics, aircraft systems, aviation law and legislation, aviation history and aviation operations right? Oh yeah, and I am a rated and practicing commercial pilot with a CFI and over 2500 hours (including teaching). You do also know that I am putting the finishing touches on a Master's in Safety with a specific focus on aviation safety, which includes (but is not limited to) aircraft systems, aviation accident investigation, crash survivability, and safety management, all of which touch daily on the finer points of aircraft design, such as systems design, implementation and function right?

Cars are a hobby for me. Aviation is a way of life.

Now, to answer your question, which I actually already answered in a previous post, let me break it down for you.

The 787 being all electric is different from any other Transport Category aircraft (this category essentially covers airliners, large size aircraft (legally identified by the FAA as anything weighing 12,500lb+ at max gross takeoff weight)) and specifically turbine powered aircraft. It is important to distinguish "transport category" because the airworthiness requirements both for operation and certification are completely different than smaller, light aircraft. They have much higher requirements for redundancy, systems design and typically systems performance, by virtue of the fact that they are operated over a much larger envelope of performance while being tasked by the FAA to ensure maximum safety for the traveling public.

If you are curious about "transport category" requirements, you can find them in 14CFR Part 25. Smaller aircraft requirements will be located in 14 CFR Part 23. In the case of Airbus aircraft, you could find the applicable Regs in the appropriate sections of the JAR's since there is a bilateral agreement between the US FAA and the European JAA for aircraft certification requirements. If you find a discrepancy between those requirements of the FAA or the JAA, the country under whose laws the aircraft is operated are in effect.

Now that we have established just a tiny bit of background information, let's discuss why the 787 is different. First, a little history and background, so you can see the transition of systems design.

When Boeing invented the 307 Stratoliner, they made it possible for aircraft to cruise in the low 20,000' range which was comfortably above the majority of the weather that occurs in the troposphere. They accomplished this by leveraging another then-new technology, the turbo-supercharger. By taking bleed air off of the high pressure compressor section of the turbo, they were able to pump the air into the cabin of the aircraft, effectively increasing the density of the air within, which in turn made it livable for the passengers without needing supplemental oxygen to overcome hypoxia. A pleasant side effect of this was also that the air being bled from the turbos was very hot, so it allowed them to keep the cabin at a comfortable temperature in the frigid atmosphere. Thus, the technology of aircraft pressurization came to be. It didn't really reach prevalence in commercial transport until the advent of aircraft like the DC-6/DC-7, Boeing Stratocruiser and the Lockheed Constellation, but the concept remained the same. Air was bled from the compressor sections of the turbo-superchargers and was pumped into the cabin to keep it livable.

Transition to the jet age in the early to mid 1950's, and nothing really changed. Rather than getting the air from a turbo-supercharger which no longer existed, it was instead taken or "bled" from the high pressure compressor section on the jet engine, usually a few stages before it went into the combustion chamber. This gave the aircraft engineers a ready supply of very hot air in very large quantities. This air was used for many things. The 3 most common uses for it though were cabin pressurization (just like with piston airliners), airframe anti-icing, and air conditioning. The need for bleed for air conditioning was a new one unique to jet engines due to the temperature and quantity of the bleed air coming from the engine. Since the air was so hot, it couldn't be pumped directly into the cabin because it would be unsuitable for the passengers. To compensate, they have to cool it. Because vapor cycle machines (such as those in a car) are very large and heavy for the volumes needed, they invented an air cycle machine which runs some of the bleed air through an orifice and essentially makes it the refrigerant. However, once we do that, the air is too cold to go directly to the cabin, so we have to re-mix it with hot bleed air, and we control the ratio to get a temperature that is suitable for the passengers. Some smaller aircraft still use vapor cycle machines, but most of the large ones use air cycle machines because they are so much more efficient at the volume required. This increased the amount of air being funneled out of the compressor section of the engine, which means that the engine doesn't produce as much power.

The second main function for the hot bleed air was in aircraft anti-ice. Since even a small amount of contamination on an airfoil surface has an extremely detrimental effect on airfoil performance (contamination equivalent to 4-8 grains of sand per square inch can reduce lift by 20-30% on a wing surface) it becomes necessary to ensure that all lifting surfaces remain clear of contamination for the duration of a flight. If we want to fly into clouds where the vapor is near or below freezing (temp drops slightly as it flows over the wing) we need to ensure that the airframe temperature is high enough to prevent ice formation on the airfoil. Supercooled water such as that maybe found around thunderstorms and strong polar fronts can be especially nasty. Luckily, the bleed air from the engines is also hot enough for this (anti-ice systems typically can get too hot on the ground leading to permanent wing damage and warping, so they are turned off) and by piping it from the compressor section of the engine through ducts and pipes along the leading edges of the wings tail, and engine inlets, we are able to prevent ice formation. However, this puts a tremendous draw on the compressor section of the engines, and when coupled with the need for cabin pressurization and cooling, can actually over-tax the engine's ability to supply enough bleed air. That gives us 2 engineering options.

First, we can increase the size of the engine, which will increase the amount of bleed air available at any given time. The downside to this is that we add weight in a bigger engine, fuel burn and end up with too much engine when we aren't taking as much bleed air off the compressor. This is also more expensive, although it has been done.

Second, we can ensure a steady supply of bleed air by running the engine at a higher power setting, ensuring that there is enough air available for our needs. This is also a common solution, but also increases fuel burn, because in situations where we need more bleed, we have to keep the power up. This is frequently why you will see an airliner make greater use of the spoilers during descent if the airplane is being operated in bad weather vs if the anti-ice is not required. You have to make more bleed air, which makes more thrust, which means the spoilers have to be used to keep the aircraft from accelerating during descent (especially if there is a minimum rate required by the approach profile). This also wastes gas.

In a typical airliner, we have the same problem during climb. If we bleed more air to keep the airframe deiced, and the cabin livable, then the engines produce less power here too. So we can either oversize them, or we can spend more time climbing at a higher power setting, both of which require more fuel burn.

Even in cruise, we still burn more fuel, because we still have to bleed air from the engines to keep the environment livable, and again, we burn more fuel than we would otherwise by not having the engines supply the air. When you consider the ducting, the air cycle machines, and then all of the ducting required to get the air into the cabin, you get a pretty large pressure loss system wide.

This is exactly why Boeing switched to electrically driven pressurization systems, because it prevents them from needing bleed air from the engines, which in turn allows them to save fuel. Interestingly, all wings are electrically deiced on the 787, but the engine inlets still use engine bleed air.

When you consider that the effectively single piece composite fuselage is also much more efficient at being pressurized (think of a polymer balloon being inflated and expanded, rather than a balloon made of many small sheets of aluminum riveted together) and can run at a higher cabin pressure than a typical aluminum structure, that would further exacerbate the amount of bleed air needed, reducing efficiency more than a traditional aluminum fuselage aircraft. One of Boeing's main goals with the 787 was to reduce the cabin pressure altitude (the altitude your body feels like it is sitting at during flight) in order to increase comfort, reduce anxiety and reduce jet lag. The non-engine driven pressurization system aids this because it doesn't put more bleed air burden on the engines, and in fact, removes it altogether, thus saving about 5-10% in fuel burn. Since aircraft use high voltage and high frequency AC power systems, generating the current to run a large pressurization system isn't a big problem.

Again, as I mentioned before, keep in mind that a 787 is burning 4-5 tons of fuel per hour in cruise, so 5-10% over thousands of hours per year is a BIG savings in cost. This fuel savings could amount to several hundred thousand gallons per year, per aircraft, leading to several hundred million a year in saved fuel expenses.

The 787 also eliminates the pneumatic engine starting system, which further reduces complexity and weight, and saves from having to rob from one engine (or the APU) in order to start another engine. Typically, unless a "huffer" is used, a typical engine start sequence would involve starting the APU to drive a pneumatic compressor, which is then used to turn an engine. Once the first engine is started, it can take over and cross-feed high pressure air across the aircraft to the other engine(s) in order to start it/them. Once that process is complete, then the APU can be shut down because the main engines are now supplying the bleed air and the electrical power (as well as any hydraulic power). For the most part, the APU is actually only used during ground ops at the gate (unless ground power is hooked up instead), engine start, and to provide power and ventilation after engine shutdown (if ground power is being connected). The only other typical use for the APU is during emergency operations if an engine fails, or electrical power is lost. In "conventional" airliners, it might also be used to provide pneumatic air for attempting to restart engines, but in the 787, it would only provide power for the starter/generators on the main engines.

In the case of the APU on the 787, it works conventionally like any other aircraft. The main difference is that instead of producing pneumatic power, it only generates electrical power. However, the electrical system appears to be fairly conventional in terms of how the battery is used. Traditionally, NiCAD batteries would have been used where Boeing is now using an Li-Ion setup, but that isn't necessarily bad because NiCAD packs had a lot of the same issues as the Li-Ion ones, in terms of potential overheat and runaway fire scenarios. Like I said, any NiCad pack on an airplane is required to have a specific temperature gauge for that pack to ensure it didn't overheat and catch fire. However, the purpose of the Li-Ion in the APU system is the same. It is there to provide a large amount of power to get the APU started. Going back to our emergency requirements, remember that the APU may have been sitting cold soaked in the tail of an airplane (at ~ -50C) for hours on end, which would make it harder to start. Couple that with the fact it burns Jet A, which isn't exactly the most volatile stuff on the planet, and one of the concerns with emergencies in twin engine jets is being able to get the APU started readily during an emergency scenario. In fact, twin engine airliners flying long-range over water missions (ETOPS or Extended Twin-engined OPerationS) have specific and special APU requirements that normal 3 or 4 engine airliners do not have to ensure maximum probability of APU start.

The advantage of the Li-Ion pack over the NiCad is that it would be smaller, lighter, and wouldn't have any of the memory and deep cycle issues that NiCad packs had. The other advantage is that an Li-Ion pack is good at providing a very large current for a relatively lengthy amount of time, which is what Ni-Cads were also good for. They had a relatively constant discharge voltage and amperage until they got to the end of their charge (everyone who owned a NiCad powered RC vehicle experienced this). That operating characteristic is ideal in aircraft because it allows you to be sure you are going to get the juice needed to keep the gas turbine spinning sufficiently while it is being started (especially when it might not want to start). If it lights off when it isn't spinning fast enough, you get what is called a "hot start" and you can literally junk a multi-million engine in seconds.

If you look at the pictures of the Li-Ion battery that is the fire culprit on the 787, you would see that it isn't very big (as I said its primary purpose is to get the APU running). Certainly not big enough to be an issue because of the electrical design of the airplane, and it certainly isn't shouldering the load of the aircraft's electrical system.

Also, just as a matter of reference, the 787 is still largely conventional with exception to the elimination of engine supplied bleed air. The controls are still hydraulically powered, and the main pumps are still engine driven. The back-up pumps are electrical, and not all conventional aircraft have electrically driven backup pumps, although that could have been as a result of improving fly-by-wire safety, or just because the system was already in place to power them. Interesting fact about the 787, it has more backup electrical generation than an A380, despite having half as many engines.





 
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