Airplane had been on the ground for eight hours, no reports of lightning anywhere near LHR

Speed of Sound
 

SoS I have been having the same thoughts, as I 'believe' that ET do not have the rear crew rest areas installed on the 787 at the rear, so straight away there would be differences from standard production types.

I am presuming that all of the original services that would have fed into this rest area would still be roughly in that location, albeit disconnected and (hopefully) all safely capped off and secured. The internal finishes and fittings would therefore also be nonstandard in this area. So could this combination cause some kind of detrimental enviromental change in the area where the ELT is located?

Given the number of ELT's in use its either the ulimate s*ds law that this has happened on a 787, or is there something specific about this ET version?

Is it known if there are any other operators using this configuration?

deggers316
 

The ELT is located FORWARD of the rear pressure bulkhead. That is why they were able to tackle the fire from the rear cabin.

If this had been in flight then most likely the flight crew would get down quickly enough to avoid explosive decompression once the fire burned through to the outside. From that point on, aggressive use of the rudder and elevator would need to be avoided as the tail section would more than likely distort as a result of fire/heat damage rather than just fall off as happened with JAL 123.

phil
 

A fire axe and a portable oxygen mask but nothing to protect their heads from falling debris some of which may be burning. :(

It makes me shudder to think of some poor brave soul or souls attempting this in the knowledge that if they are not successful they would need to not only retreat but evacuate passengers forward of this position, all while strapped in for an emergency descent possibly with O2 masks deployed.

In the absence of a final report, we have to assume that this could just as easily have happened in the air.

Anyone working for Boeing PR having a moan about their bad luck needs to catch themselves on.

What a mess:-


Boeing 787 Safety Move Splits Airline Action on Honeywell Beacon
By Robert Wall and Chris Cooper


July 19 (Bloomberg) -- Boeing Co. 787 operators are grappling with conflicting regulatory guidance after U.K. safety authorities called for the deactivation of an emergency beacon linked to a fire on a Dreamliner at Heathrow airport last week.
U.K. charter carrier Thomson Airways removed the Honeywell International Inc. locator within hours, while Japan Airlines Co. has inspected the device but faces a local legal requirement to have it on board, according to spokesman Kazunori Kidosaki. Poland’s LOT said it has made checks and the part is “fine.”
Implementing the recommendation to disable the beacon --which signals a plane’s position after a crash -- may need an airworthiness directive, according to Dominique Fouda, a spokesman for the Cologne-based European Aviation Safety Agency. The emergency locator transmitter is part of a minimum equipment list, though can be made inoperable in some conditions, he said.
“Under European regulations, ELTs can be temporarily deactivated for maintenance while the aircraft continues to fly,” added Richard Taylor, spokesman for the U.K. Civil Aviation Authority, in an e-mail. “The temporary removal can be extended for as long as necessary.”
The U.K. Air Accidents Investigation Branch yesterday urged the U.S. Federal Aviation Administration to initiate action for the deactivation of the Honeywell part after determining it was the only system in the area of the fire on an Ethiopian Airlines Enterprise 787 on July 12, adding that the event “could pose a significant concern” had it occurred with the plane airborne.
Ministry Decree
ANA Holdings Inc., the biggest 787 operator, hasn’t removed the devices because Japanese aviation law requires them aboard, said Tokyo-based spokeswoman Megumi Tezuka. If the FAA, the certification
Boeing 787 Safety Move Splits Airline Action on Honeywell Beacon

authority for the Dreamliner, ordered the removal of the components and Boeing issued a directive it would do so once Japan’s transport ministry published a decree, she said.
The FAA is reviewing the U.K. report “to determine the appropriate action,” spokesman Lynn Lunsford said yesterday.
Boeing would issue instructions to airlines about how to remove the beacon and provide assistance as needed, said Doug Alder, a spokesman for the Chicago-based company. The emergency locator can be removed quickly and won’t idle the 68-jet fleet.
LOT Polish Airlines SA, the first European carrier to get the 787, “anticipated the situation and we had already checked emergency locator beacons on our 787s before the U.K. safety board recommendation,” spokesman Robert Moren said by phone. The beacons “are fine, so we are not deactivating them.”
Visual Checks
United Continental Holdings Inc., the sole U.S. operator of the composite-plastic plane, has performed visual checks of the transmitters on its six 787s “with no findings,” Christen David, a spokeswoman for the Chicago-based company, said by e-mail.
India’s aviation safety regulator will make a decision after Air India Ltd. -- which operates seven 787s -- receives a directive from Boeing, Arun Mishra, director general of civil aviation, said in a phone interview. Rohit Nandan, the carrier’s chairman, didn’t immediately answer calls and a text message.
Indian rules also stipulate that all aircraft be fitted with an ELT device that meets FAA standards. Only aircraft used for training or research are exempt, according to the rules published on the aviation regulator’s website.
Norwegian Air Shuttle AS, which leases Dreamliners from International Air Finance Corp., said it’s in “close contact” with Boeing and civil aviation authorities. “We will of course follow all the instructions that we are given,” spokeswoman Astrid Mannion said by e-mail today.
Qatar Airways Ltd., the only Middle Eastern 787 operator, declined to comment.
The ELT beacon, using lithium-batteries, is suspect because it’s the only power source in the area of the fire, though investigators are still probing whether the device combusted or was set alight by an outside source. The incident is the first involving more than 6,000 such Honeywell devices, the AAIB said.

25 degrees C is baking? The 787 underwent flight testing in Phoenix and Yuma, where it would of been 45+ every day.

According this Honeywell Rescu 406 AFN2 Brochure, the storage temperature range of the ELT is -55 to +85 Celsius. I could well imagine it getting close to that if not higher if in direct sunlight for long enough. The upper end of the operating temperature range is specified to be lower, 55 Celsius, which I would have thought easily achievable.

Various studies on car interior temperatures, where vehicles are closed up and left in the sun show startling high temperatures. Temperatures for the air alone can be as high as 50 Celsius. Surfaces (especially dark surfaces) inside vehicles tend to be much hotter, as this is the source of heat for warming the air. Dashboards are known to reach about 100 Celsius.

If there is any comparison here, without insulation for the ELT, I would have thought the installation site unsuitable in this instance.

Wouldn't most of the heat in a car be from direct sun through the glass windows?? Surely through a fuselage wouldn't get that hot ever???

And Ethiopia ain't exactly cold? "Danakil Desert is about 125 metres below sea level and the hottest region in Ethiopia where the temperature climbs up to 50 degree Celsius"

Speed of Sound & Phil:- Smoke Hoods should be available whereas a fire axe is only mandated by some authorities, if I recall correctly.
Perhaps there is a study on how carbon fibre composites dissipate heat by conduction as compared to aluminium which does it very well.

The outside temperature has some effect, but the primary source of energy would be from the sunlight. If there is no cooling breeze either, that could exacerbate the problem.

The heating effect on cars is not down to the glass. From what I have read, it would appear that the presence of glass merely affects the rate of heat rise. One compared cars, buses and vans. The van reached the same temperature as the car, it just took longer.

I also wouldn't expect the ELT to have problems the first time it is exposed to temperatures outside its specifications. It might need several excursions outside the permitted range, before problems can occur. If indeed this is what caused it in the first place.

Temperature.
 

Just trying to think outside the box here, but does anyone know where this aircraft was parked during its grounding earlier in the year?

If it was in one, single location, it may have been subjected to three months of regular heat/cooling cycles which may have had a detrimental effect on the folded cathodes inside one of the cells, especially if they were still switched on during the period.

Yes, I know that this happens to most aircraft on a daily basis but we need to look for something which sets this particular device apart from all the others and a regular very hot days followed by very cold nights cycle may have played some part in degrading the battery.

Has any PLB/ELT/EPIRB ever - in the entire history of these devices - burned up and amaged an an airplane, boat or other vehicle :confused:

To me this just does not seem all that likely.

I certainly wouldn't rule out temperature as a cause and I don't have numbers but I still suspect the difference in solar heating between composite and aluminum will not be vast and given the number of these in service (over 6,000?) if there was a marginal temperature effect we would have seen it by now in something else.

I'm guessing of course but suspect it will turn to be either really bad luck, some installation issue or - and my favorite - that the version of this ELT used in the 787 has been 'tweaked' in some way that has left it vulnerable.

But how many of the others sat baking in a dessert for 3 months?

Another difference could be what happens if a battery does go, do the aluminum instalations have a heat sink effect and or nothing flammable nearby?

It seems that something else had to have caught fire to cause the level of damage seen.

It is also possible that protective insulation (if pressent) around the ELT allowed higher temps to devlope from a battery "thermal event".

Grounded 787's sat out in the Houston TX sun for several months recently, no ELT fires.

But there has been talk that the Ethiopean plane is different to the standard layout in this area, i.e. the crew compartment is not fitted. This may have changed the way the ELT is mounted/contained in this aircraft. Is it now more enclosed than in other 787's, thus reducing the movement of free air around the ELT? Was any insulation omitted due the absence of the crew compartment, thus reducing or removing any protection the ELT might have normally had?

- yet -

Also not as hot and I as I recall the incident 787 was first back in service.

That said even if the "hot soak" is a factor worst case it should have caused a safe battery fail not a fire.

The real question (assuming the battery is the initiater not victim) is why a fire started.

No but that doesn't mean no ELT battery damage.

If I was Honeywell I'd have that unit swapped out and have the batteries back in the lab for a thorough examination.

Is the "other aircraft system in the vicinity which, with the aircraft unpowered, [...] capable of initiating a fire in the area of the heat damage" a zonal dryer ?
Those are well known for overheating...