Repairing the 787: The prospect of repairing or writing off the 787 has gained fodder almost on the same level as speculation over the cause of the fire. There have been several articles, including this one yesterday in the Puget Sound Business Journal and this one today from a former NTSB member, writing in Forbes.
Throughout development of the 787, Boeing said repairing the composites was not something they were worried about. But most context related to ramp damage or other minor issues. Clearly, though, Boeing being Boeing, we are confident that engineering took a look at major fuselage damage potential.
In the extreme, Boeing can simply replace the entire aft end, which is depicted in this illustration.
Boeing famously replaced the nose section of a TWA 707 in 1969. The nose section of a BOAC 707 was undamaged and later grafted onto TWA 707-331 N776TW, which had been hijacked as flight 840. The nose was blown off in a Jordanian desert. The repaired aircraft flew for 10 years with TWA. The cost to repair was $4m, according to Wikipedia information (about $20m today).
Update, 9am PDT: Jon Proctor, in Reader Comments, says this BOAC angle is incorrect. He supplied the following photos that demonstrate the replacement nose was fresh from Boeing’s factory.
Jon Proctor photo.
Jon Proctor photo.
Qantas is famous for never having a hull loss, repairing damaged aircraft that others might scrap as beyond economical repair. The Airbus A380 involved in the high-profile QF34 engine explosion was out of service for a couple of years and cost something like $180m to fix, but it flies on today.
A Google search of damaged aircraft that have been repaired and returned to service shows a long list of aircraft that suffered what appears to be far greater damage than the Ethiopian aircraft. The difference, of course, is that the other aircraft were metal and this is composite.
The cost will go beyond the fuselage crown and related structure. The interior, with smoke damage, is toast. Who knows at this stage what damage has been done to systems, either from the fire, the fire-fighting or the knock-on effects.
ELT: Yesterday’s news that the Electronic Locator Transmitter is being looked at as a possible cause of the Heathrow Airport 787 fire predictably created a flurry of media activity over the implications of this prospect. The Wall Street Journal broke the news and a media frenzy ensued. WSJ posted an update late yesterday. We accessed through our subscription; Readers may try Google News to see if it is passed the pay-wall today.
The New York Times has this piece on the ELT and the potential role it may have had in the fire, either as a source or a propagator.
Flight Global has a piece that puts some good perspective on this prospect.
There are two dimensions to this issue: first, is it economic to repair. Maybe it makes more sense to harvest the parts and scrap the rest. Given the fact that it is L/N 44, it might also have some bad heritage of the early models.
Then again, scrapping a more or less new aircraft is a nightmare in terms of publicity. Less for the airline, but rather for the manufacturer. I think they will repair it regardless of the economics. Repairing the A380 that was damaged in Singapore wasn’t a straightforward economic decision, either. It cost 145 Million USD, half of the list price and probably 80% of the actual price (the aircraft was MSN014!).
I doubt you can just rebuild the tail with a new ‘snap on’ replacement part, there is extensive wiring and other stuff that is done after the initial body join.
I suspect the smoke damage alone will probably consign it to the boneyard.
Puget Sound Business Journal:
– Tuttle said his comments are only “initial thoughts,” adding that he and colleagues haven’t had any chance to investigate the damaged aircraft…
– …He also confirmed the concept that Airbus’ more conservative hull design for the competing A350 — carbon-composite panels fastened onto ribs — may turn out to be better, at least for repair.
– “Airbus has said, ‘If we have a problem, we can repair it by replacing one or two of these large panels.’ That is exactly where we are now at, a situation that will tell us quite a bit.”
I agree with the comment about the damage on the aircraft. Until we have a chance to view the actual damages we cannot say for sure if this airplane is repairable or not. Even then, I remember when the terrorists detonated a bomb inside that TWA 707 which COMPLETELY destroyed the cockpit of the aircraft. I never thought this airplane would ever return to service again. But it did.
I wonder what happened to that Air France A300 which was highjacked to destroy the Eiffel Tower but had to land in Marseille to refuel. The SWAT team invaded the aircraft and bullets were flying everywhere inside the cockpit.
As to the repairability of the A350, I think it has an advantage over the 787 because it is more conventional. It is designed and built almost like an aluminium airframe.
– Given the lack of history on repairs to composite aircraft and the criticality of the area of damage, I would be concerned about any repairs in that area that were short of a complete replacement of that section. However, replacement of that section might be prohibitively expensive and not cost-effective.
There is no doubt in my mind that technically it can be done. But wether it is worth it or not will depend on how much damage was done to other parts of the aircraft. I am particularly preoccupied by the fact that the large electrical panels of the aircraft might have been soaked up by the foam that was used to extinguish the fire, even if they are far away from the fire area.
The aircraft from air France has been scrapped because the fuselage (including the cockpit) was so damaged.
There’s a movie “l’assaut ” with final assault from french swat.
Thanks Ludo. I saw that movie a while ago and it made me realize how close France was from going through its own 9/11. Kudos to the brave and efficient SWAT team. Not to forget the courageous and smart captain of the aircraft; and all the others who contributed to make this “Mission Impossible” a complete success.
Contrary to folklore stories, the replacement nose for the TWA 707 damaged by a bomb in August 1969 did not come from a damaged BOAC 707. It was built new at the Boeing factory at Renton, Washington, and transported from Seattle by Pregnant Guppy to Damascus International Airport in Syria where the damaged airplane was located (not in the Jordanian desert). I have TWA archival photos that show the replacement nose being prepared for departure from Seattle; advise if you would like me to send them.
What about putting it out of sight in a hangar, declare you need to fully understand what is the best way forward & hope meanwhile the attention shifts to 787-9 first flight?
Where is this so called 787-9 first flight distraction coming from keesje? I’ve been waiting for any news of the impending 787-9 roll out and, despite diligently looking for it, have not found any. Cool photo though, even if it was taken 1.5 months ago.
Boeing may have the parts needed for repair already on hand. They retired ZA-001 through ZA-003 that can be used as donors, or they could take one from the assembly line.
Having the part is not good enough (and salvaging a barrel would not be a smart idea in this case). The problem will be to bring the jig and all tools.
Yet they may do it to save the reputation but it won’t be cheap.
Boeing’s AOG has a very good reputation. They have completed seemingly impossible repairs before, with only one failure that I know of. That was the JL-123 B-747SR aft pressure bulkhead repair that resulted in a crash of that aircraft some 8-9 years after the repair. Since then, Boeing AOG has completed hundreds of successful repairs.
The WSJ article basically confirms the thinking that the 787 electrical system could NOT have caused the battery in the ELT to catch fire. The ELT is a very reliable device with long track record in service. It contains a battery that is not rechargeable, and is a passive device, not connected to the that evil electrical system the people like to blame so much.
However, it makes perfect sense that Honeywell has been invited to the investigation. The ELT battery contains a substantial amount of chemical energy and the AAIB undoubtedly wants to assess how the device could have contributed to the fire. The notion that Boeing leaked info about the ELT being investigated in order to confuse and distract the public is ridiculous, the stuff of tinfoil hat conspiracy theorists.
It will be very interesting to see what steps will need to be taken to make the damaged airframe flight worthy. I’m assuming, of course, that section replacement is what will be needed, and that Heathrow is not an appropriate location.
The WSJ article confirms nothing. It is true that the battery in not rechargeable, but it is still connected to the aircraft electrical system for cockpit interaction. I don’t know if it is an evil system, but they say the devil is in the details. And in this case lots of details can be found in the 14,000,000 lines of code that drive this aircraft.
IF there was a sneak circuit or short somewhere, **then** the 787 fubar electrical system **might ** be involved. But absent that- the ELT is NOT part of the electrical system
The aircraft computer network is NOT considered part of the aircraft electrical system, as it is independently wired and controlled.
But you’re technically correct, the WSJ article really does confirm nothing, as it is not authoritative. But hey, it’s not like that small detail is stopping any of the wild speculation here.
“that evil electrical system the people like to blame so much”
Tell that to the FAA pilot that put a burning 787 down in Texas in a black cockpit.
‘I’m assuming, of course, that section replacement is what will be needed, and that Heathrow is not an appropriate location.’
My thoughts. In my post this week-end I sugggested ferrying the ship back to base could be possible by putting the big metal plating over the aft fuselage. However there is probably a lot of pipes, wiring bunddles, etc destroyed. that doesn’t help..
And you have to find a crew.
“Tell that to the FAA pilot that put a burning 787 down in Texas in a black cockpit.”
Not really! The cockpit was not even close to being black as you say. Now for reality:
“A source familiar with the details of the situation said yesterday the pilots lost the primary flight displays while on approach to Laredo. Boeing disputed the claim this morning, saying the pilot did have a PFD on landing. The 787 flight deck allows both to be true. In load shedding situations the outboard displays which are the typical home for the PFDs, enter a reversionary mode and disable the pilot’s outboard display and first officer’s inboard display… …While the primary flight display would be lost due to the electrical issue, the PFD would be sustained on the left inboard and right outboard display.”
I see this is another one of your fish stories where the tale gets grander and grander on every retelling. Just like your 4 years late (up from 3.5) and at least 4 fires (2 in flight) caused by the electrical system (electrical system only caused 1).
“Not really! The cockpit was not even close to being black as you say. Now for reality”
The screens were black because a pannel was burning. Coincidently an FAA inspector was flying and landing the aircraft, the working display was on his side. If 1 display are working out of xx, we can discuss is the cockpit is dark during daytime, if a blackbox is black etc. IMO evasive semantics.
“Just like your 4 years late (up from 3.5)”
You prefer “more then 2 years” I guess?
“at least 4 fires (2 in flight) caused by the electrical system (electrical system only caused 1).”
Let me guess, the batteries are not part of the electrical system in your book.. or the flames from a battery were no fire.
Can we please reduce the amount of Newspeak & call a cat a cat when we see one.
News flash for you: The NTSB has not yet officially determined the cause of the battery fires. So, you don’t know that the electrical system caused the batteries to go into thermal runaway mode, do you?
Yes, I normally consider the battery a part of the electrical system except when people try to use the battery incidents to support over-generalized statements about how this never before tried electrical system has mysterious bugs and gremlins in it.
“Can we please reduce the amount of Newspeak & call a cat a cat when we see one.”
Can we please not constantly exaggerate, subtly stretch the truth, and use made up “facts” to make our points?
With the Dreamliner we are generally speaking in a SNAFU situation. But the electrical system is indeed FUBAR. And it could even be a case of TARFU. So when the next fire comes around it could actually put the Boeing management in a BOHICA predicament. 🙂
I hope everyone understand that this is humour, not ranting. I sympathize with the hard working Boeing employees who would like to extricate themselves from this recurring nightmare.
yes i understand your humour.
KISS – a burning cigarette;-)
If there were a crew rest area there, this would be the most plausible theory!
It’s actually a cigar that was left in the toilet by Joe Patroni, a famous aircraft mechanic. The guy works at the airport and plays in Airport. 😉
An used crew rest area is not required for a burning cigarette in the garbage can of a lavatory. The empty space for the crew rest area is just located above and that’s it.
You missed the humor.
George Kennedy, alias Joe Patroni in Airport (1970).
It’s like saying the CEO in not part of the company. EVERYTHING on this aircraft is controlled by the software that is programmed into those computers. Especially the electrical system. It is so complex that no human being would be able to manage it without the help of a complete set of entangled software instructions.
I respectfully disagree with your analogy. Having glitches or interruptions of the 120V AC power in my building, or even an electrical fire in my building rarely not interfere with the ability of my boss and I to communicate via e-mail to our laptops. Of course if the server room happens to be on fire then that is a different story, but that is a single point of failure, which is handled on an aircraft by having redundant systems.
The point is that the 120V AC power system that runs my office lights, the machines in our lab, and keeps my uninterrupted power supply charged is separate from the low voltage Ethernet system over which my boss and I communicate. There is a lot of protection electronics between the 120V power system and the ~2-3V Ethernet com system.
The same is true on the 787. There are probably several layers of isolation circuitry between the 787 electrical power system consisting of 4 standards, (235 VAC, 115 VAC, +-270 VDC, and 32 VDC) and the computer network, which I believe is Ethernet, and the flight control system, which I believe has its own separate dedicated wiring.
As far as I know, the ELT is not connected the electrical power system at all, but is possibly connected to the computer network.
Good point Mike- however I recall a few earlier notes- regarding revisions of wiring on the first ?? airframes regarding separation( physical ) of the control and monitoring systems. And I’ve heard of significant rework needed of vendor supplied/connected wiring harnesses, etc . Any of which could easily lead to sneak circuits between monitoring and power circuits.. The same mentality of putting battery monitoring circuits in the same box as the battery- and finding instrumentation grounding fried when the battery went bonkers.
Locally we have an old line electrical company called greybar electric-
I opine that BA saved money ( upfront ) by using Fubar Electric . . .
Don, your point about sneak circuits is well taken. Ground loops are bad as well. Sneak circuits and ground loops used to be the bane of my existence back when I was doing a lot of pulse power work.
If power levels got onto the data lines, hopefully there is other fried equipment that might give the investigators some clues.
“But hey, it’s not like that small detail is stopping any of the wild speculation here.”
So right, Mike! The replies part of this blog have become the Nancy Grace Show of aerospace. A combination of hyper-imagination, dreamed up IMHO’s and sour grapes current and past employees. Oh well, don’t let facts or rational discussion get in the way of a good rant or fanboy blabber.
Your rant threshold is pretty low, dude.
When the Dreamliner Lithium-Ion batteries went up in smoke, we were told not to speculate and just wait for the answer. Well, the answer never came. On the day of the Boston Marathon bombing FAA/NTSB said, “Go fly!” and we’re none the wiser.
Do you even know what you are talking about? The Li-Ion batteries have been redesigned, they are installed inside a steel box and have a new recharger and battery health monitor system. There has been no reoccurrence of the original problem.
BTW, the NTSB has no authority to lift an airplane grounding. Their investigation into the JL B-787 in BOS is not complete.
The fact that the ELT incident took place shortly after the 787 exited the no-fly zone stunt everyone. But it must have sent a huge shock wave throughout the FAA. I wonder how it is going to deal with the situation this time around. I understand its decision to let the Dreamliner fly after Boeing found an acceptable solution. But this time around it cannot let the aircraft fly for too long without knowing what is really going on with this aircraft.
When the Comet experienced a series of crashes and mishaps the engineers went through the aircraft to se if there was anything wrong with the design. They could not put their finger on anything specific, but they nevertheless implemented more than 50 modifications. After that the aircraft was authorized to fly again. Then there was this big crash over the Mediterranean Sea. One of the passengers had time to write a last letter to his wife:
“My darling, the blue Mediterranean Sea is under us and the coast appears in the distance as a dark shadow. In the sky there is much light, and never as now have I been so happy.”
Redesigning the battery enclosure is not an explanation, it is a kludge. I should have said “in the aftermath” of the Boston
Marathon bombing, not “on the day of”. Sorry about that.
Boston Marathon bombing: April 15th, 2013
FAA announces 787 grounding AD will be supeceded: April 19th, 2013
FAA supersedes grounding AD: April 26th, 2013
Just wondering if the on board aircraft health monitoring system would have detected anything in a “shut-down” aircraft.
Depending on how this works out, this could be free PR that might be used by Airbus in future A350 presentations when it comes to the panel vs barrel debate
It has since been outsourced to the Chinese division of Tarfu Electronics. 😉
@ Mike and Don
You guys are talking about electricity and electrical devices. I am talking about software and lines of code. The electrical system is MANAGED by software commands.
Boeing AOG. The example is a 767-300. (946 KB .pdf)
I think I saw a documentary of that repair on TV. Impressive stuff!
I think it’s a great opportunity for Boeing AOG to step forward and repair this plane under the intense scrutiny of the world’s media. It would allay some worries that linger with the composites, repair thereof. But it would (may*) be insanely expensive.
I just want to see what, where AOG is on composites, they have a heck of a team on aluminium structures.
When a guy switched from metal to composite he has to start almost from scratch. But many individual are qualified on both.
I guess it’s an opportunity for them to show the airlines what they can do — I think* AOG teams are always their best FAL guys anyway, so best on the 787 line(s) for that.
What really puckers this old retiree is that BA in the days of Apollo-saturn had a first rate group of engineers and techs whose sole purpose was to do a sneak circuit analysis of the whole damm apollo stack – and they got ( from my memory ! ) awards and lots of publicity at least in the Boeing news- and elsewhere.
And there have been local articles about the demise on 787 of similar groups of ‘ sparkies” put together for 777 and earlier models.
I’m NOT saying that that is what happened re the ELT- but neither can it be ruled out.
I’m not a electrical Engineer by profession ( I’m a mechanical ) but in the late 60’s I designed and tested the first electromagnetic riveter using high voltage capacitor banks to drive a couple of opposing flat plates… while figuring out how to use low voltage strain gages to get needed force v time data. The absolute separation and shielding requirements taught myself and a few others about keeping the damm circuits separate and properly grounded.
The resultant circuit issues were not sneaky at all – more like a pile driver – no direct connection short circuit needed …
IMO -Boeing has stuffed the equivalent of a megawatt power station in a small box using computer analysis techniques more suited to instrumentation and laptop design.
Cool stuff Don! Is that riveter you designed, or a later derived version, still in use today?
One of my pulse power projects involved using 16 capacitors (100uF each) charged to 10kV to dump about 80kJ of electrical energy into a piccolo igniter inside the chamber of a 30mm gun. All the while we had to make various chamber and barrel pressure vs time measurements using piezoelectric gauges. Lots of nasty things could happen if we were not careful, like blowing up our $3500 digitizers.
A bit off topic but here is the thumbnail .The year was 1967-68 while working on the SST program. I coined the word- phrase Electromagnetic Riveter or EMR. Using opposing drivers connected to a 4kv NASA capacitor bank we drove 3/8 inch A-286 alloy and Titanium rivets ( slugs- which are headless rivets ) By 1970-71 hand held versions were used on 747 inboard wing panels- and by 1980-approx Boeing used the same basic system ( a low voltage version developed by ELECTRO-IMPACT http://www.electroimpact.com/ on what is known as the automatic spar assembly tool or ASAT. The low voltage version was the outgrowth of a few UW types being given a research contract by Boeing. That system is now used worldwide for similar riveting applications in aerospace.
Since I used NASA/government equipment on a government partially financed program ( SST ), and due to certain Boeing patent issues- neither I or my then supervisor could patent the process- a few later related patents were obtained by others.
AS to how to handle the stress gages? actually quite simple- run parallel -opposite polarity resistance type stress gages and wiring in a shielded circuit.
Nuff on this issue
Don, thanks for the history. It’s not off topic for me because it is interesting stuff.
This is is a colourful way of expressing it. And from what I can see you are probably not too far from realty.
av week stub re megawatt
The 787 relies heavily on electrical power for functions that were powered by bleed … starter generators, thus there is a total 1.45 megawatts of power available.
I am sure you have read my previous posts on this topic. But you are obviously not making the connexion. I have always been quite vocal about the all-electric concept and the one and a half megawatt of electricity required to achieve its goal. In fact I started screaming almost ten years ago.
I always thought this and the cancellation of the NSA were the two worst decisions ever taken by Boeing. Time could actually prove me right in both instances. But frankly I would prefer to be wrong and see Boeing continue to thrive. Maybe we can discuss this again in three years from now and review what will have happened in the meantime. For in 2016 it will be 100 years since William Boeing created this great American company.
A more complete desription by the BA Chief engineer at
Yes, I have read that transcript before. I have actually commented on it in previous threads. I once asked a few questions about it that nobody has answered yet. I am sure CM could have given me the answers I was looking for but he was out of the loop by then. The questions were related to the following description that Sinnett gave in his lengthly speech:
– Now, up until this point other modern airplanes had used NiCad, nickel cadmium batteries. And we chose lithium ion on the 787, which was a departure from the traditional NiCad applications that we see in aerospace.
– It is true that it’s lower weight, but that really wasn’t the driving factor in our design. The driving factor in our design was really the ability of the battery to discharge a large amount of energy in a very short period of time. And this was required for two different functions at an airplane level [braking and APU start].
The questions I asked were the following:
1- Would it be technically possible to substitute Ni-Cad for Li-ion on the Dreamliner?
2- What would be needed to achieve that?
3- What would be the consequences on the operation of the aircraft?
What was behind those three questions is that if the weight “was not really the primary factor in the design”, would it still have been possible originally to design the all-electric architecture around NI-Cad? And is still possible to adapt it? Apparently for Airbus it is not a problem on the A350. But what about the 787? Are the all-electric requirements beyond the capabilities of Ni-Cad? The latter is a key question.
Correct me if I am wrong, but my understanding is that Ni-Cad can only produce 28 VDC whereas Li-ion can produce 32 VDC. If that is the case, could the electrical system be redesigned to adapt it to 28 VDC without affecting too much the aircraft braking capacity and APU starting? And is the Ni-Cad recharging rate sufficient to satisfy the Dreamliner’s voracious appetite?
At this stage these may appear as academic questions. But my impression is that we have still not reached the bottom of this.
Uhh norm- this is not about 787 main batteries- and the 28 v 32 volt issue is a non starter- EXISTING ni cads are 28- they can be made for 32 volts- just add a few cells in series, etc.
Power density is an issue – but again the ethiopia issue is NOT about batteries. It may be about ground power ..
I have never said it was about the main batteries. My post above discusses a different topic that was triggered by your Sinnett transcript, which reminded me that my questions have remained unanswered to this day.
But it looks like the ELT incident is indeed about the battery. Its own Li-ion battery. Not the MAIN and APU batteries. But they all appear to share the same disease.
That is what a lot of people are saying. Apparently the ELT and the instrument panel that controls it in the cockpit are wired in an isolated loop. In other words the LTU and its instrument panel could be taken out of the aircraft and would still function normally as if they were still inside the aircraft. But I am not 100% sure of that. I cannot demonstrate this because it is an irrational impression. A gut feeling if you want. So for the time being the burden of proof remains with me.
The point I want to make though is that I would not be surprised to learn that there is an interaction, direct or incidental, subtle or obvious, between the ELT system and the rest of the aircraft.
Probably a software virus. 😉
I am beginning to wonder if the ELT is a red herring that just happened to be where the “incident” (I gather the AAIB are not yet calling it a fire!) It doesn’t sound as though its battery holds sufficient energy to have initiated whatever caused the damage.
As for repairs, since the visible damage appears to span the rear fuselage/tail joint I wonder if both these would have to be replaced.
To have an idea of the most likely repair solution see this Boeing presentation (Page 18 – Bolted repair development): http://www.vaughn.edu/assets/downloads/atec-2008-01.pdf
I don’t think that the repair will take 6 months or even a year as some analysts wrote already elsewhere. The job should be pretty straightforward and done quite quickly after the investigation is finished. The most expensive item will be the complete renewal of the cabin as it will be impossible to get the smell out of the seats without replacing them all. I see the cabin renewal as a bigger bottleneck that the pure fuselage structure repair.
That is if no foam leaked under the floor where all the electrical panels are. These have a tendency to go haywire once in a while.
All i can think of is to scrap the burnt out 787 as i will not fly on a jinxed repaied aircraft it’s the safest way as no one has been killed yet.
I guess you won’t fly aboard the QF A-380 (MSN-14) that had the engine explosion, either? It took a while for Airbus AOG to fix that airplane, too.
@A380: It is really a shame that you have chosen “A380” as your nickname as I am personally really proud on my achievements on the A380 development. Using this nickname to write such unsubstantiated BS makes me really sad. I really can’t (under)stand this fanboyism! I assure you that I and my colleagues have a lot of respect on the achievements of our competitors in Seattle and I think they have as well despite the fierce competition. So please stop making comments like this.
Please understand that the problem is not OAG’s reputation but the one of the whole Boeing wrt the 787 full barrel composite design.
The stake is high.
WASHINGTON (Reuters) – Honeywell International Inc (NYSE: HON – news) on Wednesday said it would temporarily remove its emergency locator beacons from Boeing (NYSE: BA – news) 787s if asked to do so under recommendations that sources said British authorities could release within days as part of an initial report on a fire on a Dreamliner jet in London last week.
Investigators have been looking at several components, including a lithium manganese battery in the Honeywell emergency locator transmitter (ELT), as possible causes for the fire that caused extensive damage to a parked Ethiopian Airlines 787 in London last Friday. The battery is made by New York-based Ultralife Corp (NasdaqGM: ULBI – news) , a source told Reuters on Monday.
Britain’s Air Accidents Investigation Branch (AAIB), which is leading the investigation, may suggest temporarily removing the devices from the new Boeing Dreamliners while the probe continues, according to one source familiar with the probe who was not authorized to speak publicly.
A second source familiar with the investigation said the AAIB could issue a report in the next few days that includes some recommendations, without giving details on the proposals.
Honeywell’s emergency beacons are in use on a wide range of airplanes.
The latest fire on board Boeing’s new composite airliner comes on the heels of a three-month grounding linked to problems with much larger lithium-ion batteries on the plane.
Sources close to the investigation say it is turning out to be more complex than initially expected given that the fire caused severe damage to the upper portion of the jet’s rear fuselage. As in the earlier probe, investigators are finding it difficult to pinpoint the cause of the fire.
A spokeswoman for the AAIB on Wednesday reiterated that Honeywell’s ELT was one of several components being looked at in detail as part of the investigation, but said it would be premature to speculate on the causes of the incident.
AAIB has declined to identify any other components that might be under scrutiny.
Boeing says its highest priority is the safety of the new airplanes, and it is working closely with authorities to “understand exactly what happened – and why,” wrote Randy Tinseth, vice president of marketing for Boeing Commercial Airplanes, in a blog posted on Wednesday.
“While the investigation continues, the 787 fleet is flying as normal. We’re confident the 787 is a safe airplane and we stand behind its overall integrity,” Tinseth wrote.
The AAIB’s possible move to remove ELTs was first reported by The Wall Street Journal, which said that ELTs are not required for a plane to be certified for passenger flight.
The Journal, citing a person familiar with the matter, said the AAIB is preparing to ask the U.S. Federal Aviation Administration and the European Aviation Safety Agency to assess the necessity of the devices on 787s.
Officials at the FAA and U.S. National Transportation Safety Board (NTSB), which have both sent representatives to London to assist with the investigation, declined comment, referring queries to the AAIB.
A spokesman for the European Aviation Safety Agency said he had no information on the elements contained in the WSJ report
Honeywell said the report was based on “anonymous speculation” and said its officials had not been contacted by British or U.S. authorities involved in the investigation.
However, spokesman Steve Brecken said Honeywell always puts safety first and “would support an action like this as a precautionary measure if our team, or the AAIB and NTSB, determine it’s necessary to do so.”
Honeywell says it has built over 3,000 emergency beacons since they were first certified in 2005, and insists that it has not seen or experienced a single reported issue with them.
The FAA did issue a special airworthiness notice in 2009 in which it advised airlines to replace the antenna used by an earlier version of the Honeywell transmitter because it had failed in tests. Other global regulators published similar advisories at the time.
Asked about that notice, FAA spokesman Lynn Lunsford said there was no indication of fire risk linked to the earlier antenna problems.
The ELT, which is positioned in the upper rear part of the 787, sends a signal that leads rescuers to downed aircraft.
ELTs are largely redundant on most large jets since their routes are closely tracked by radar or air traffic controllers , except for long-range polar routes, said one aviation expert.
All planes also come with flight data recorders and voice data recorders that have sonar “pingers” that are activated in the event of a crash into water, when the ELT devices would not work anyway, said the expert.
The FAA also had no comment on the Journal’s report that some FAA officials were arguing to shift jurisdiction for the fire investigation to the U.S. agency, since the Ethiopian plane was parked, rather than in flight, and was certified by the FAA.
(Reporting by Andrea Shalal-Esa; Additional reporting by Alwyn Scott in Seattle; Rhys Jones in London and Tim Hepher in Paris; Editing by Gary Hill, Tim Dobbyn and Leslie Adler)