I understand that... I was just illustrating that a charging problem might cause the swelling and overheating and it might not be a battery issue per se. Especially since Thales (charging system) has been 'in hiding' so to speak.
I heard that the charging and control system has been a problem from the beginning. No outstanding problems with the Yuasa batteries.
It is reported that the battery in the ANA 787 overcharged prior to failure. Japan: Over-charging preceded ANA 787 battery malfunction
That's a little disconcerting. Since this problem was not only just discovered through aircraft going into service, why was it not rectified in the test stages prior to the delivery of the first aircraft? Was it just thought not to be serious enough to delay deliveries? All the best, Andrew.
As I have mentioned before, every new program that I was a part of had some new problems parts of which elude on-going fixes. It's a process of fixing from the top layer and working your way down into deeper layers. Sometimes the boogie men keep popping up like the gas bubbles in a swamp and don't become visible until other fixes are made. The 787 is a leap forward in many technologies and will take a lot of fine tuning to get everything as near perfect as the engineers can. IMO I think that the suppliers that provided the control systems are the culprit here.
Well, for the good of Boeing and the Dreamliner I hope you are right...i.e. - that the batteries themselves are OK provided the charge/discharge is managed by the controllers correctly. It would seem to be much easier to replace the charge/discharge controls rather than the entire battery packs.
What is the safest thing to do though? Should these sorts of batteries have ever been used in a plane? Pete
Well, you could say no - but then, jet fuel can blow up too if it is not safely contained and managed.
Thales has a huge investment in the A350 which is undergoing certification testing at the moment (not flight, yet), and are probably working feverishly to ascertain any commonality between anything they put on the 787 with what they have designed for the 350.
Interesting: Dell laptop chargers caught fire, GM hybrid caught fire ... While I have flown on Airbuses, I personally do not think they are considered the worlds safest aircraft manufacturer. When I used to get on a 747, I'd be completely relaxed ... that is the feeling that Boeing need to work very hard to get back with this 787. Reputations take years to build but only minutes to destroy. Pete
my guess there is a software glitch with the chargers...LI batteries are designed for heavy use, also they do not tolerate being held discharged for a longer time or be gently used, they also need variable charge voltage and charge rates, while monitoring temperatures while charging... which brings to mind the temperature range of their enviornment in which they operate and length of charge cycles. Bench testing apparantly doesn't match actual use
These batteries were involved in over 1 million combined hours of flight test without a series problem. I am certain that they were subjected to varying rates of charging and discharge.
The Hubble telescope. Mars Rover was tested and tested too ... the difference is planes are considerably more important for our safety. I manage a small IT team, testing only means so much ... Pete
Remember that the Boeing 707 had several problems that were not resolved after several years in service. One was a "dutch roll" condition that was resolved by increasing the height of the vertical stabilizer. And there was a string of problems with stabilizer and elevator trim that resulted in several notable fatal crashes, including one in Brussels that wiped out the U.S. figure skating team and another in Paris that killed many important people from the arts community here in Atlanta. On the whole, today's jetliners are much safer right out of the box. The 767 has been in service for 1982 and has been involved in only one fatal accident definitely attributed to a problem with the aircraft, the Lauda Air accident in Thailand when a thrust reverser inadvertently operated in flight.
This problem should not be too difficult to identify, solve, and ensure it doesn't happen again. Li-Ion batteries and their behaviors are pretty well understood, so most likely something is not happening the way it should (either defective batteries, defective control systems in batteries, defective control systems outside batteries, or something physical like vibration of impact or mistreatment). We should know soon enough - god knows Boeing will be "highly motivated" to solve this with the greatest of speed. I shudder to think how much this is costing them in all meanings of the word.
Jim, I was thinking the same way about past programs. Guys like you always play the game of " what if" and identify problems before they are problems and in every program the "what if's" don't always catch every glitch but they come close. The B-52 had some problems the alternator drive system that brought down an airplane near Larsen AB and one other in California. The 707 had numerous glitches, dutch roll due to the combination of dihedral and wing sweep and that was predicted by Henry Quenzler, an ex-Dornier engineer who was in PD. Also air conditioning systems that poured water on the passengers when lower altitudes were attained. The then exotic alloys bit the engineers, too. I can't recall any problems with the 720 or 727 when they were new. Believe it or not, the 737 was full of them, drag was the worst. The 747 had many, too, but they were comparatively minor except for the engines with case distortion and shaft cracks. 757 and 767 were relatively free of serious faults as was the 777 . Boeing will get this 787 stuff fixed and get the airplane back into service just like they have in the past but the toughest problem will be to zip up the mouth of the press.
You have to fix the problem first. The press is ALWAYS after sensationalism... that's what they do. Once it's fixed and ends, it will slowly 'go away'. You almost never hear about the fairly recent A-380 wing cracks, or the long ago uncommanded rudder movement on the 737. They're just not in the public mind.
NTSB today is reporting that they found an internal short in one of the cells of the battery from the JAL 787 causing the thermal runaway. NTSB finds signs of short circuit, thermal runaway in JAL 787 battery failure
NTSB "These events should not happen as far as design of the airplane," Hersman says. "There are multiple systems to prevent a battery event like this. Those systems did not work. We need to understand why." My question is, "Why wasn't this happening during the thousands of hours of test flights? ..........or did it? Something smells........................................
I seriously doubt that Boeing covered up any battery issues during flight testing. I suspect that one of the suppliers started cutting corners once it went into production.
ANA has been flying the 787 for well over a year... is this the first incident for them? I wonder how many hours their 787s have flown. How many for ALL in-service 787s? Are these the only 2 battery incidents in the public domain? Doubt the FAA would have allowed it out on the market if they'd had issues with the battery system during the 1000's of hours of testing.
