Ethiopean 787 fire at Heathrow

[olasek]

. My guess
is that the unsafe chemistries from years ago are no longer used.

Technology improves but "safe" never means absolute safety, there is always statistical chance for this first occurrence. "Today" is probably better than "years ago" but far from perfection.

[Coagie]

LI -x batteries do NOT need Oxygen to continue to flame- the chemistry is such they generate thier OWN oxygen.

ELT batteries are NOT chargeable

ELT is not normally connected to Aircraft electrical system- note I said NORMALLY - but ' sneak" circuits due to poor grounding, flaky connections, crossed wires, etc ** could ** possibly exist. Battery protection diodes can fail for example internally, etc. LI-x fires can be like a cutting torch.

Model airplane LI-x batteries can and do catch fire if abused/shorted/etc but they ARE rechargeable.

DWS and Ancient Mariner, after reading your posts and looking at the picture of the burned battery, It seems like I have a lot to learn about Lithium batteries. Some of them are really scary. Maybe, like the battery in the closet, the one in the ELT caught fire for no apparent reason without even needing "crushed wires". That is extra scary. In a hermetically sealed box, it might be more like a bomb! I'm making the lithium battery too analogous to more common batteries I'm accustomed to. I may not always be right, but I'm clever enough to know, when I need further study. As much as I know, I learn a lot from our brainstorming, and appreciate everyone's patience with one another.

[kenneth house]

Environmental conditions can be critical

Ancient Mariner showed photos (many thanks) and said:

[The batteries were taken straight out of the box and put on shelves, they were airfreighted! to us and we could not find anything wrong with the boxes. ]

i wonder if the reduced pressure environment of the freight cargo hold may have been an overlooked factor causing internal cell damage that later erupted in the storage room (e.g. venting, cell wall flex and distortion, expansion of the foil roll, shorting of internal electrodes to foils or case, etc.) A cell may look fine on the outside but be damaged and slow-cooking on the inside.

[Volume]

As Reuters reports, ANA found damaged wiring in their ELTs.

Japan's ANA Holdings Inc, which operates the world's biggest fleet of Boeing Co Dreamliners, said it found damage to the battery wiring on two 787 locator beacons during checks after the devices were identified as the likely cause of a fire on another aircraft in London this month.

[EEngr]

787 fire investigation looks at pinched battery wiring | Business & Technology | The Seattle Times

"The two sources suggested that Honeywell might have replaced the batteries at some stage before delivery of the jet because the devices sat on the shelf during the years-long 787 program delays."

Sat on whose shelf? Are these ELTs 787 specific parts? Or are they used across various models? If its the latter, then I'd expect Honeywell to pull stock and ship it as various orders came in. If the 787 program was a couple of years late, they'd ship units built later on.

If it was Boeing's shelf, then who replaced the batteries? If Boeing took possession of the units and shelved them, then they'd be responsible for maintenance. Seeing how this was not standard in-service fleet maintenance, who did they send into the warehouse, screwdriver in hand, to swap the batteries?

Given several possible scenarios, this looks like it could be a maintenance procedure problem. Airlines take steps to make sure that work is performed by qualified personnel. because this is a part of their normal business function. But out of sequence manufacturing or maintenance can be a planning headache.

[Coagie]

If it was Boeing's shelf, then who replaced the batteries? If Boeing took possession of the units and shelved them, then they'd be responsible for maintenance. Seeing how this was not standard in-service fleet maintenance, who did they send into the warehouse, screwdriver in hand, to swap the batteries?

Great point. Say if the ELT were manufactured in 2006, someone might find it prudent to put fresh Lithium batteries in them, since they are supposed to be good for 10 years, before installing them in a plane finished in 2011 or so, so the carrier wouldn't need to turn around in 2016 and replace the battery. Someone unfamilier with the particular ELT, changing the battery, would explain a lot. Honeywell should put a tamper evident seal on there various beacons, and require that, when their battery is 10 years old, the whole unit be swapped with a new one, and the old one sent back, to get a new battery. One of those "No User Serviceable Parts Inside" kind of things. It's for what is sometimes referred to as "Post consumer control of your product". Maybe it's already like that? Maybe someone on the forum knows?

[Coagie]

It's probably more complex than this, but, just a thought or two. If the ELT uses a Lithium Magnesium battery, I hope the Magnesium isn't in the same form as was used in "Mag" wheels! Hard to control fires from car wrecks was the reason "Mag" wheels aren't made of Magnesium any longer, but instead are made of Aluminum. . Maybe this type of battery should only be small, for use in low capacity situations, like in smoke detectors, watches, and cameras, so the stored energy isn't enough to burn through routine precautions. I'm sure an alert beacon transmitter would use a lot of current, if it's to transmit for very long, so it probably has a pretty high capacity battery. I've brushed up on my knowledge of different Lithium battery technologies, and it seems like using high capacity ones and/or storing them in close proximity to each other, may be a no no, across the board, until better practices in quality control, design, and use are practiced!

[theroadie]

"It's probably more complex than this,"

To be sure. It's MANGANESE, not MAGNESIUM. And it's in a dioxide form, not elemental.

[Machaca]

ANA finds damaged ELT battery wires

Reuters reports:

...ANA...said it found damage to the battery wiring on two 787 locator beacons during checks...

The damage was slight, but the beacons have been sent to the manufacturer, Honeywell International Inc, for inspection...

[Coagie]

To be sure. It's MANGANESE, not MAGNESIUM. And it's in a dioxide form, not elemental.

Magnesium, Manganese, ... What's the difference? Ha, ha ...I didn't know what sort of battery the ELT used, I thought it might have been something like this: Torqeedo 24-Volt Lithium Magnesium Battery : Cabela's
A Lithium Magnesium battery. I thought I'd read, was the battery in Ancient Mariner's picture, but I could be wrong. Anyway, it didn't seem far fetched, that the ELT might use the same type of battery. Of course, the Magnesium, might not be in it's elemental state either, so could be perfectly safe.

[fenland787]

Magnesium, Manganese, ... What's the difference?

What's the difference? Cor, strike a light.....no....on second thoughts don't, or you'll find out!

[no-hoper]

The type of battery (5 ea /pack) should be one of these:

UHR-CR25650-LVP (U10027) - Battery & Energy Products: Commercial | Ultralife Corporation

UHR-CR34610-TSO (U10028, U10029) - Battery & Energy Products: Commercial | Ultralife Corporation

[Machaca]

Coagie:

Magnesium, Manganese, ... What's the difference? Ha, ha ...I didn't know what sort of battery the ELT used, I thought it might have been...

All such relevant, and serious, details have been covered in this thread. You would be best served by keeping up before contributing.

[bsieker]

Coagie,

the quoted website also confuses magnesium and manganese: the torqueedo batteries are also Lithium-Mangenese (Mn): This has nothing to do with Magnesium (Mg).

[DWS]

United finds pinched wiring on ELT also

United Continental Holdings Inc. ( UAL ) said it has found pinched wiring in one Boeing Co. 787 Emergency Location Transmitter as part of Federal Aviation Administration mandated inspections.
The inspections come in the wake of a fire aboard an empty Ethiopian Airlines 787 at Heathrow Airport on July 12. U.K. Investigators recommended inspections as part of its findings.
A spokeswoman for United said inspections of its fleet of six 787s are now completed and the "defective" transmitter has been sent back to supplier Honeywell International Inc. ( HON ) for evaluation.
The spokeswoman said there was no disruption to United's flight schedule as a result of the inspections.

Read more: United Finds Pinched Wiring on Boeing 787 Transmitter

GEEZE- Ethiopia, Japan, United - all finding pinched wiring on ELT ??

maybe from same batch- ??

Or did the faster and cheaper mantra catch up with Honey-bucket er Well ??

Or were they produced on a Monday like De-troit cars- after a hangover ??

And about inspection and Q/C ??

[Coagie]

the quoted website also confuses magnesium and manganese: the torqueedo batteries are also Lithium-Mangenese (Mn): This has nothing to do with Magnesium (Mg)

Bernd, I stand corrected. Thank you. Germans always were good at chemistry. Maybe I should use something other than a Cabela's Outfitters catalog for my research? Anyway, I do stand by my broad brushing of being careful how to use and store higher capacity Lithium batteries. It seems the thermal runaway chance is just too great, to use or store them in anything but a very careful manner! If they are too close together, one bad apple can spoil the bunch. There is some talk of using Magnesium and Sulfur for some kind of electric car batteries. Hope the Magnesium isn't in a dangerous state in that case.

[Coagie]

All such relevant, and serious, details have been covered in this thread. You would be best served by keeping up before contributing.

Machaca, Wico! I have read the entire thread, but I got sloppy, and was trying to go by memory, when I should have reviewed the earlier posts. Apologies to all. BTW: Lighten up Machaca, Life is too short.

[Coagie]

GEEZE- Ethiopia, Japan, United - all finding pinched wiring on ELT ??

maybe from same batch- ??

Guess they need to check the lot number, and see if they are from the same production run, then if so, have all of them pulled, in case the person inspecting didn't have his glasses on. I don't know about Honeywell, and I hope this isn't happening at Honeywell, but in some high tech manufacturers, to save money, when there's an item that doesn't require a constant production, rather than have permanent employees to assemble the item, some companies just wait until they have enough orders to justify a production run, and then hire temporary workers, just for that run. They try to get experienced workers, but it sure opens things up for mistakes. Quite often, the mistakes are "pinched wires" as a matter of fact.

[SLFgeek]

If any wires were to become pinched, and if these wires only had a very thin layer of Teflon insulation, rather than much tougher PVC based coverings....

Been lurking quietly and following various aspects of this thread. The above may be an important clue, especially with respect to the ELT. One of the interesting features of teflon insulation (FEP and PTFE) is that in a stressed situation it will slowly do something referred to as 'cold flow'. I first witnessed this about 40 years ago, involving some teflon insulated wire-wrap circuits, on a Univac backplane, where the wires had been pulled too tight against a 90-degree turn, and the teflon insulation eventually cold-flowed to the extent that it made electrical contact with the wire-wrap post that the turn was against. That the battery wire in the ELT appear to have been 'pinched' (based on various sources) and the likelihood that it could be teflon insulated as well, this could be a delayed cold-flow event. The unit was assembled, tested, everything looked good, and then (over time) the pinched insulation flowed back, and a short developed. One possible theory on how this occurred. If so, it is very lucky that the incident happened on an airframe sitting on the stand, with no pax on board.

NASA makes mention of 'cold flow' on this page (right most column, first entry) ...
NASA Parts Selection List (NPSL) - Wire Insulation Selection Guidelines

[Radix]

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