Man in a Shed: Boeing 777

Like many people I watched the early reporting of the crash landing at Heathrow of a BA Boeing 777 in amazement.

It was also a great example of how technology has changed news. Most of the reports and pictures in the first phase of the incident came from members of the public to the BBC's News 24. The passengers had mobile phones and weren't going to be stopped by being corralled away from the traditional press.

It was slightly frustrating that the BBC presenters didn't seem to ask the right sort of questions of the passengers. ( If the plane was banking at 45' just before landing - why didn't the passengers notice. Due to force distribution they may have felt level, but looking out of window would have told another story ).

From their reports no orders to brace for a crash landing seem to have been given. The crew were perhaps too occupied the reported emergency of dual engine failure, but it must have been close to ground to not allow any time for a warning.

Now double engine failure is almost unheard of - except for fuel problems. Reports say the aircraft had sufficient fuel in its tanks after landing. ( Update an explanation for possible fuel contamination is provided here ).

Either way this is very significant as a lot of trans-Atlantic air travel relies on the low likelihood of dual engine failure.

We don't yet know how far out the engine failures happened. But one thing is sure official sources of information are being very quiet right now.

Terrorism has apparently been ruled out - but something doesn't fit right now. Perhaps fuel contamination which was only evident as the tanks emptied ? The electronic on the aircraft have to be a prime suspect with some sort of common mode failure being to blame. The proximity to the ground might give a clue - maybe the action of lowering the undercarriage caused a wider system failure or some other form of electromagnetic interference - the mostly metal body should protect the aircraft.

Still there is the near miraculous safety of the passengers and crew, and those on the ground, to be grateful for.

Still odd they allowed Brown to fly to China in what I assume is another BA 777.

PS It is worth speculating as to why all BA 777's and other airline 777s haven't been grounded given the reported total electrical failure of the aircraft. Perhaps something is known about the cause after all. This is the part of the story that is making the least sense to me right now.

Update the following is being reported on a number of sites including the Telegraph:

"Everything was normal and there was no warning or anything and suddenly 'boom’, the power’s gone.

Also remember only a few days ago the incident with an Australian Boeing 747 losing power near Bangkok. Qantas blame a leak of water, but Boeing don't go along with that. Again all engines were unable to deliver generated power ( 4 of them ) though it must be assumed it happened at a much higher altitude as the aircraft flew on for 15 mins on batteries.

Again we have some form of common mode failure, though the distance from the ground seems to rule out ground based interference.

First indication from the Air Accident Investigation branch is expected towards the end of Sat. If it was a bird strike then the evidence will be obvious with the engines - but equally if they want to blame birds they won't be able to without the evidence as the engines look to have survived at least in part.

It is perhaps interesting to speculate if the aircraft actually did better landing of soft turf than on tarmac ? Obviously if the undercarriage had held tarmac would be better. But perhaps there's a lesson for some emergency landings here.

Update: The BBC have a page on speculation here. It suggests a range of options, which now include Attack and wind shear. It remains an oddity of this event that the aircraft was flying the reserve route that the British Prime minister was about to take on a similar model aircraft I assume. ( Tony Blair always had a BA 777 ).

I don't see how wind shear would shut both engines and lead to power failure - but I'm not an aircraft engineer so maybe I'm missing something here.

Thinking about what was reported perhaps the aircraft angle at 45' was down to the start of stalling on one of the wings ( meaning loss of lift from that wing and a subsequent rotation of the aircraft). The aircraft must have been at the very limits of its glide path. In which case we have been very lucky that the plane was not full as it probably would not have made the field of Heathrow airport.

Witnesses report high engine noise - I have no idea is windmilling engines could generate that or if some power was still available.

No one reports smoke from the engines or such a trail. ( Would that be an expected indication of a bird strike ? Or just a fire. ) Also you would expect some damage to the front of the engine which given the aircraft's location would be hard to hide from the media.)

Also does the lack of a fire indicate the engines were shut down on landing ?

What ever the truth it will be an episode on Discovery channel before you know it.

Mike Swain of the Mirror suggest early deployment of reverse thrust ( which explains the engine noise ). If that's the case I'm amazed the aircraft managed a controlled descent at all. Not sure how that relates to the loss of power.

Someone may start to look at any software involved in controlling the aircraft. Opening up the possibility of sabotage - but this must be very unlikely.

Update: BA have just had a press conference which presented the crew but gave no details of the technical side of the incident, citing the ongoing crash enquiry. I have no idea if that's normal procedure, but it seems odd. I guess BA have to be careful due to potential legal implications and the potential for legal action. However the staff and management at BA have given a very strong sign of support for the cabin crew.

Pictures of the engines are now available over at Flight. The interpretation placed on them is that one engine had no power on impact. The other is missing a blade, but no support for bird impact is given.

Update AAIB have reported (interim report), saying the aircraft suffered engine failure with a loss of power 2 miles out when the pilot attempted to power up. The power was being controlled by the auto throttle. The crew attempted to increase power manually didn't respond. Still no aircraft grounded.... ( This confirms the information provided in the comments by an anon source ).

Further there are some interesting points being made in the comments which are worth a look (a number of anon posting there ! )

20/01/08 Anon 10.09 has made a detailed description of might have happened. If its correct then I suspect heads may roll. Maybe he's right, maybe he's not ( that's the wonder of the internet you never quite know), but the description of fuel practices may raise some questions. It also might explains why there have been no precautionary groundings for checks.

24/01/08 The accident investigation now seems to be focusing on the fuel supply. Reports repeat that their was adequate fuel on the aircraft when it 'landed'. See this report on fuel incidents by David Millward in the DT.

15/02/08 Heathrow crash theories are revealed apparently based on a leak to a US pilots web site. In essence its common mode failure of either engines due to - fuel issues, hardware or software. The software issue is causing most concern due to its wide implications. However I still think due to proximity to the ground at the time of failure that electromagnetic interference should be considered, maybe from a hostile source - it will be interesting to see if it is specifically ruled out. ( Perhaps its something that would never be admitted to anyway ).
http://cosmos.bcst.yahoo.com/ver/251.7/popup/index.php?cl=6453176

Also see more details for this discussion on the Pilots of America web site, which seems to have quite a bit of detailed knowledge - including a picture from inside the aircraft.

Update 13May08 Attention continues officially to focus on the fuel system. There is concern the unusually low temperatures over Russia may have lead to the fuel viscosity increasing to a level that caused problems in supply the engines at a greater rate during landing. See the Daily Telegraph here. It seems strange that this problem hasn't been reported before, though that doesn't rule it out. However given the survival of the aircraft there should have been all the evidence required to discover any pilot error and that hasn't emerged as the case, I assume clearing the crew.

Update 4Sep08 The official interim air investigation report is in and ice crystals are being blamed. Apparently the same result has been reproduced by Rolls Royce. I'll be looking over the report over the next day or so ....