U.S. safety board finds clue on 787 fire; faults FAA review

Not safe at all...

"Boeing had estimated that a battery smoke event would occur"

Known concern, now priority refit . . .

"The company has marshaled an extensive team of hundreds of experts and they are working around the clock focused on resolving the 787 battery issue and returning the 787 fleet to full flight status," Boeing said Thursday.

I agree, not safe, no way, no way!

There were multiple signs of short-circuiting in the cell, which led to an uncontrollable rise in temperatures, or thermal runaway, to adjacent cells, she said.

Not sure why they had to tuck away this massive piece of information and then ignore it for the rest of the article. Internal shorting is almost always caused by manufacturing defects, meaning the Japanese investigators either didn't do their jobs properly or refused to announce their actual findings

Internal shorting is almost always caused by manufacturing defects...

Correct and it is inherently a problem with Li-on batteries. I still find it incredulous that this type of battery would be banned from transport on aircraft for awhile due to being a fire hazard and then an aircraft manufacturer uses it as a systems battery.

Droll QuarryFeb. 08, 2013 - 11:32AM JST

I still find it incredulous that this type of battery would be banned from transport on aircraft for awhile due to being a fire hazard and then an aircraft manufacturer uses it as a systems battery.

Lithium ion batteries aren't banned at all. Only thing banned is large shipments of lithium batteries, which are completely different and not rechargeable. Why they picked lithium cobalt instead of the dozen other formulations that have just as high of energy density (though a bit less max current) is beyond me (and a long list of more knowledgeable people). There are much safer alternatives out there, like the lithium iron phosphate ones that don't go into thermal runaway until the same temperatures that NiCd batteries also fail at.

basroilFeb. 08, 2013 - 11:52AM JST ,,,Lithium ion batteries aren't banned at all.

In January 2008, the United States Department of Transportation ruled that passengers on commercial aircraft could carry lithium batteries in their checked baggage if the batteries were installed in a device. Types of batteries covered by this rule are those containing small amounts of lithium, including Li-ion, lithium polymer, and lithium cobalt oxide chemistries. Lithium-ion batteries containing more than 25 grams (0.88 oz) equivalent lithium content (ELC) are forbidden in air travel.[115] This restriction is due to the possibility of batteries short-circuiting and causing a fire.......... and ............Investigators: Short circuit in Dreamliner's lithium ion battery led to fire

Droll QuarryFeb. 08, 2013 - 12:14PM JST

In January 2008, the United States Department of Transportation ruled that passengers on commercial aircraft

That's passengers, air cargo flies with different rules.

This same testing was done before the planes went public so what changes in testing have occurred for it to matter? If it's the same process that failed why would it work now?

Fine mess the French and Japanese have gotten poor Boeing into. No merci!

Wired.com has a great detail write up. While the battery packs meet specifications, there are serious questions on if the design was up to the task.

"The lithium-ion cells within the 787 batteries use a graphite-coated copper anode and a lithium cobalt oxide-coated aluminum cathode. The anode and cathode are separated by a very thin polyethylene film known as the separator."

This is design is what Chevy went through with the Volt. The thin film can have problem where it deforms and causes a short. Next thing you know, thermal run-away. Chevy ended up applying a ceramic coating to the separator film. The 787 uses a plain film and the design is highly suspect. Bottom line, the cells are not designed half as well as the ones used in modern electric cars like the Volt or Tessa Sedan.

Basroil when the USA inspectors came and cleared Yuasa you weren't convinced . When the last article was up stating that Thales the French company designed the batteries and electrical system and commissioned GS Yuasa to manufacture them you had no comment. Yes there is a fault inside a battery that they found . As to why the problem is there they have said above again to conclusive answer to it yet.

Quality cleared ....design ??? It's not a Japanese design like you have previously stated. Yuasa manufactured these based on Thales/Boeing requirements.

Let the professionals make the conclusions and issue bulletins. Pretty hardcore negativity coming from your direction concerning this GS Yuasa company that's world renowned for production of these electrical devices.

CrazedinjapanFeb. 08, 2013 - 05:46PM JST

USA inspectors came and cleared Yuasa you weren't convinced .

NTSB and FAA did no such thing, only Japanese inspectors probed the company. And as I said then, manufacturing errors are not necessarily systematic, and it's quite possible all the bad batches are already somewhere other than the factory, and whatever cause it was fixed long ago.

CrazedinjapanFeb. 08, 2013 - 05:46PM JST

It's not a Japanese design like you have previously stated. Yuasa manufactured these based on Thales/Boeing requirements.

LVP-10 and LVP-65 are both Yuasa designs that are not necessarily 787 specific. This article stated an internal short caused one cell to burn, triggering ones next to that to burn. That's clearly within the scope of the LVP line.

The information being released is not enough to be biased against any one particular company. What ever issues Boeing and related companies that are involved release will probably not quell your obvious superiority in the knowledge of avionics. Which is why you have a near perfect record for thumbs down on every post you put up.

Boeing and related companies have been through this mess before. It's great to see issues being addressed with the total concern for passenger safety at the front.

Small correction US representatives were here in Kyoto honing in on quality control as stated in a previous article

"U.S, Japanese and Boeing representatives have this week been at the Kyoto headquarters of GS Yuasa Corp, which makes batteries for the 787, looking at everything from manufacturing quality to technical standards."

http://www.wired.com/autopia/2013/02/ntsb-787-dreamliner/

Boeing, along with investigators in the United States and Japan, have focused on the lithium-ion battery from the start. And today's announcement that the problem appears to have started with a short circuit within a cell is exactly what battery expert Dr. K.M. Abraham suggested was the problem when we spoke with him last month. The lithium-ion cells within the 787 batteries use a graphite-coated copper anode and a lithium cobalt oxide-coated aluminum cathode. The anode and cathode are separated by a very thin polyethylene film known as the separator.

The separator is roughly the same thickness as cellophane and behaves in a similar way. There doesn't need to be a tear or a hole to create a short circuit that can cause thermal runaway. The material is very thin -- typically around 25 microns, according to Abraham -- and small irregularities in the thickness can be enough to lead to problems. A section of the separator that is just 20 microns thick might be enough.

"It could be a stretch, it doesn't necessarily have to be a big hole, just a weak point where you have low resistance," Abraham said. "It can be a problem when you have such a very large surface area electrode where there is a lot of inhomogeneity in the current distribution."

The variable thickness of the separator material could be a result of manufacturing, but also could occur during charging and discharging of the battery. A very small short might lead to the growth of a lithium crystal within the battery cell.

Abraham, agreeing with comments made by Tesla Motors CEO Elon Musk, said the relatively large cells in the 787 battery pose a problem. The large surface area of each cell increases the chance that an irregularity could lead to a short, Abraham said. The problem of the separator changing thickness due to heating is something addressed in the batteries used in the Chevrolet Volt. The separator is less likely to change thickness due to heating, according to Abraham.

"That was overcome in the Chevrolet Volt separator where they reinforced the separator with ceramic particles to mitigate the shrinking problem," he said.

According to the NTSB, the separators used in the 787 batteries are not reinforced with ceramic particles.

She faulted the battery’s certification under the Federal Aviation Administration (FAA), which cleared the all-new 787 as a safe aircraft more than two years ago after extensive testing.

“The assumptions used to certify the battery must be reconsidered,” she said, adding that her agency was conducting tests to determine “why hazards were not mitigated.”

Soooo... she's saying "extensive testing" was not enough? I really get tired of these FAA - NTSB squabbles. It happens with every aircraft incident. The NTSB resents that they don't have the regulatory authority the FAA does (the NTSB can only make recommendations), so they get their "digs" in every chance they get.

CrazedinjapanFeb. 08, 2013 - 05:46PM JST

Pretty hardcore negativity coming from your direction concerning this GS Yuasa company that's world renowned for production of these electrical devices.

You've been misreading all the posts then. I merely stated that it is almost certainly a problem in manufacturing, one that is likely transient. Only thing I blame them for is trying to push blame away from themselves when clearly their batteries did not meet the specifications set. If the issue is found to be just that, a transient problem in manufacturing, and Yuasa is found to have helped try to cover it up, then I will rail on them for sure.

I think what this is going to come down to is when everybody is in charge then nobody is in charge. Boeing has some overall specifications but way too much engineering work was left to Thales and GSY.

That's not a new thing per se. My uncle worked for Panasonic Battery for a decade. It was pretty common for them to assign engineers to design the power and charging system for the customer.

The problem is we're not talking about consumer electronics. We're looking at an airplane that has all sorts of forces and dynamics that really need aerospace engineers to understand. The consequences could be catastrophic. You look at Tesla and Chevy. They are very hands on with battery design, chemistry, control and charging electronics even though they are outsourcing to Korea, China and Japan to finish the product.

Ultimately I think Boeing needed to own the engineering chain and needed to be much more hands on. And the really sad thing about this is they are solving problem that have already been solved by companies like Chevy and Tesla. This didn't need to happen.

Ultimately I think Boeing needed to own the engineering chain and needed to be much more hands on. And the really sad thing about this is they are solving problem that have already been solved by companies like Chevy and Tesla. This didn't need to happen.

Batteries in an aircraft bear no resemblence to batteries in an automobile. Chevy and Tesla didn't have to design batteries that would continue to function in an explosive decompression situation at 35,000 feet like batteries in a jet airliner must do. If the batteries are in a non-pressurized part of the aircraft, that's even WORSE as the batteries must withstand daily cycles of pressurizaion and depressurization from the atmosphere. Car batteries are pampered cousins, by comparison.

@Fadamor That argument would be more convincing if there was any sign that GSY has applied some sort of renforcement to the separator film. Or if they had augmented the chemistry with something similar to NMC. From what I'm reading they focused on containment measures and monitoring. And for the most part that more or less worked as the thermal runaway situation didn't seem to create a fire that spread to the rest of the plane (ala Swissair 111 fatel In-flight Entertainment System Fire.)

There's going to have to be a change in the batteries. This isn't going to be fixed just in the power/charging systems.