Straws in the wind....
 

From previous posts:
- 'Rainliner'
- Wiring thinly coated with non abrasion resistant Teflon
- AAIB request to inert the ELT only applies to the 787 (ie, believe problem is 787 specific and outside the ELT)
- Non standard installation (no crew rest area) - 'unused' wiring

If the problem is moisture and / or abraded wiring leading to a short it would be very bad news for Boeing - because it potentially raises generic questions about the 787 design that are not localised to the area around the ELT.

Hi,

Having worked through this thread, cause of fire ranging from coffee
maker to elt, i'm wondering just what we are being fed here.

As far as I can see, the elt batteries are completely encased in
thick aluminium and the batteries also have inline fuses to limit the
current to a safe level in the case of a short circuit, so how could
they ever cause a fire ?.

Some of the most reliable technology, over millions of hours with no
significant event and suddenly we have a major fire in a very new a/c
with a significant history of problems and malfunction.

Sorry, but I just don't believe in such coincidences :-(...

I would assume that the mounting of the ELT battery/transmitter would be on a small rack and that only the antenna itself would be direct skin mounting, all be it with a gasket!

Airbus' John Leahy: Boeing 787 Unreliable, Immature Aircraft
 

Haven't seen this gem posted here:


TOULOUSE: A senior Airbus executive hit out at rival Boeing's troubled Dreamliner on Friday, saying the aircraft was clearly not reliable and suggested it was rushed to market.

"It's pretty obvious that this airplane is not reliable and does not have mature systems," Airbus sales chief John Leahy told reporters at a ceremony to mark the 1,000th delivery of the company's A330 plane, to Hong Kong airline Cathay Pacific.

"You can keep it flying but it's going to cost you a lot of maintenance," Leahy said, in the first comments by Airbus management about the Dreamliner's difficulties.

"What they've got is an architecture that is not mature and that will eventually become mature. It's going to take a lot of time, a lot of money, a lot of cancelled flights. And maybe redesign quite a few systems onboard."


Airbus executive says Dreamliner 'not reliable' - The Economic Times

What insightful and helpful comments from someone who, I presume, considers he will not be perceived as having a vested interest in knocking Boeing and it's products!

Speed of sound,
Codswallop, total and utter codswallop.

Jazz Hands,
Around 150=-160 F

Speed of Sound,
And where and doing what are the totally unprotected SLF in all this?

Aeromech3
Good comment, but what are all the SLF doing in all this other than breathing toxic carbon monoxide, cyanide and a host of 90 other toxic nasties in dense smoke via FST or just watching IFE in spite of dense FST smoke with no protection whatsoever?
The whole onboard fire fighting a critical internal FST fire just doesn't wash, sorry. And RIP to all onboard in that event.

Does seem to burn quite easily and am quite surprised that some sort of
inerting or halon extinguishant wasn't mandatory for critical areas of
this airfix a/c...

In flight I suspect one might have to consider using the ocean to put it out.

No Photos?
 

Can anyone explain why there have been no photos of the inside damage? There are many who could have legitimate comments that might help understand what happened with photos.

If it was "burning" batteries in the beacon that started the fire, and they were still involved when the fire crew arrived, then it's unlikely that anything short of cooling the batteries below their reaction temperature would stop the energy release. I understand that the failed batteries do not require external oxygen to start, or continue, to release heat. Presumably halon will quickly stop the burning of the aircraft structure in air, although unless it's also cooled, than the fuselage would presumably reignite if it stays hot and the halon drifts away.

I agree something here doesn't pass the smell test and is being kept quiet. Any fire investigator worth their salt can look over the aft galley and tell you if the fire started in the trash can, coffee pot or other suspected working area the crew may have utilized. This 406ELT has been used on several other aircraft for years with no history of overheating. Also the ELT battery is not of sufficient size to burn hot for more than a couple minutes if it shorted or puffed like lipo's will do when overheated. Can this ELT be activated from the cockpit like other aircraft? if so then it has a wire harness attached. I think the public and crews working this aircraft have reason to want an answer.

@syseng68kSomething doesn't add up. Okay, the AAIB have concerns surrounding the evidence they seen about the actual ignition source. I suspect the Li batteries in the ELT may or may not be to blame. Forensic examination of the battery housing should establish relatively quickly whether an external heat source was involved. Likewise if the heat generated by a battery short radiated beyond the casing etc..

Methinks the AAIB is taking a very cautious approach.

One thing to remember is that the elt batteries have only a fraction
of the capacity of the main a/c batteries, have a very different
chemistry and wouldn't suffer from the same problems in service.
Such batteries are also often current limited by design. ie: They
would be very unlikely to have enough available energy to burn
through the metal enclosure.

I had to source some long life lithium batteries for a project some
years ago. They were Lithium Thionyl Chloride chemistry, C cell sized
cell, with a high 19.5A/hours rating, but only at very low drain
current. They were rated for 125 C service, with welded stainless steel
outer case. Also found some other Lithium cells during the search that
were rated at over 200C, for applications such as deep oil well data
logging.

I find it hard to belive that these batteries could have caused the
fire, but we just have to wait and see...

It'd be hard to take this thing on an ETOPS leg right now....

They can do little else.

If you issue an edict to ground an aircraft without knowing precisely why, how do you then release it to fly again?

a good primer on battery failure
 

that explains where the oxygen originates that can cause such a strong fire that halon cannot extinguish.

Lithium Battery Failures

Which ELT RESCU 406® AFN2?
 

honeywell

There are two ELt 406, the new one RESCU 406® AFN2 more than 50% lighter than the older RESCU 406® AFN.
The AFN2 has two cells, the old AFN had 5 cells. Now i'm wondering, if really already 6000 devices of the new one with only two cells are in operation or if that number is related to all 406 ELt's with two and 5 cells.

And i'm further wondering, if this 2 cell design, which saves a 4.3 lbs in weight might have some influence onthe happening.