AAIB initial report out on BA B777 crash at LHR

[Busbert]

Based on the fact that there has been no advice from Boeing to other B777/T800 operators, it would suggest that there was some finger trouble or non-engineering failure in play.

The DFDR, CVR, QAR and the BITE/TSD from every relevant box on the aircraft will have been analysed by now. If there was an issue with the aircraft, we would have had all All Operator Wire, and probably an emergency AD by now.

The longer the silence continues, the more it looks like an operational issue.

[Magplug]

Busbert.... I, like you am a believer in simple causes for accidents and you are quite right - we would normally have seen some AD by now instructing operators to examine x,y,or x component.

However it is equally possible that there are a bunch of very clever AAIB guys who are still scratching their heads with absolutely NO idea what happened.

[SaturnV]

Magplug, I would not rate as equally possible that the AAIB is scratching its collective head in bewilderment. I think thats a small possibility at this point, given the extensive data thats available, the opportunity to interview the crew, and the ability to examine a relatively intact aircraft.

[Mad (Flt) Scientist]

With regard to the discussion about AD and Advisory Wire timings and what if anything can be deduced from the absence of the former.

I agree that it is likely that with the mass of data available that the investigators have a pretty good idea WHAT happened. What may very well be in doubt is WHY. Since an AD has to actually contain actions for the operators to take in order to assure or restore airworthiness, in the absence of a known cause there's nothing an AD can achieve, short of a mandatory precautionary grounding, which does not seem warranted at this point, since 777's are not falling out of the sky like leaves in autumn.

Even if the cause has been narrowed down to a single suspect piece of equipment, without knowing how to test for a repeat problem, there's little an AD could do.

[Fg Off Max Stout]

God help us! Never before have I seen so much uninformed bull being spouted.

This is exactly the reason that these threads will never die:

Post 302

The three Daily Mail photographs were of the same aircraft, so there was on very short finals AC power available (APU or main generators) to power the landing/ nosewheel lights.

Post 303

It looks to me that one of the DM photos is not of said aircraft - the landing lights are on!. Not something you would expect to see with a power failure and running on emergency power.

People with limited or zero aviation knowledge keep posting uninformed twaddle without bothering to read previous post and see that their half-witted pet theory was dismissed as ridiculous by those more likely to know on thread 1 page 1.

I have a reasonable amount of professional piloting experience on twin turbine multi crew aircraft, but because it is not on passenger jets I have so far bitten my tongue. I have some opinions about the accident but because of my lack of directly relevent knowledge I do not consider it appropriate to start arguing the toss - a fact that should be considered by all the taxi drivers, flight simmers, school kids etc who are clogging up the website. It was laughable initially but now it's a pain in the arse and just the sort of thing that could make PPRUNE restrict its membership to Pro Pilots only, which would be a shame.

Amongst my favourites so far include:

• B777 avionics run on Microsoft Windows so someone with a laptop used wifi to hack into the autopilot and cause the crash.
• There was no avgas in the tanks.

Sorry to be harsh but if you know virtually nothing about aviation then your opinion on this subject is worthless and simply a waste of bandwidth. Rant over!

My money is on a software snag and I have experienced numerous FADEC failures in the past that have resulted in OEI flight in a twin. However, in the poll I voted for alien intervention to illustrate the futility of these theads. I know nothing of significance about trains or ships, and next time there is a rail or shipping accident I will STFU. Others take heed.

[G-ZUZZ]

I fly the B777. I'm a little dismayed by the rot being posted here but since some people are focussing on the A/T system, here are a few facts:

• The levers MOVE with power changes about as much as in a B737 or B757 or B767.
• The pilot can feel (and see) the levers move.
• If the aware pilot knows he needs more thrust and the levers aren't moving, it IS obvious by the lack of movement, among other indications.
• If the A/T system is over-ridden by moving the levers and then the hand-pressure is removed, the levers will return toward their orginal positions and attempt to maintain the commanded speed but only when in a SPD mode.
• In the HOLD mode the levers will stay wherever you leave them, with associated thrust levels.
• During approach the A/T system is normally in SPD mode unless manual speed/thrust control is being employed by the pilot.
• FADEC is a separate system for each engine and should not automatically be blamed here.
• The Boeing operating manual for the 777 is very light on for detail and about 10% of the thickness of what I would probably need to offer a reasonable opinion on why both engines failed to do perform as advertised so, in an apparently unheard-of move around here, I will not put forward a half-arsed theory.
• Nothing regarding thrust delivery can be determined with absolute certainty from the photos of the engines. The theories and postulations going around here are laughable.
• With loss of electrical power to the Transfer Buses, the APU would attempt to start automatically even on the ground. This involves the intake door opening. Whether it achieved this successfully in the case of BA38 cannot be determined from the photographs.
• The RAT door, if indeed it is open, may have opened due to damage sustained during the impact and subsequent ground "roll".
• 600ft/2NM is on glideslope but is not, in my opinion, enough time to recover from the overhelming surprise, remember the passengers, look down select a PA option and blurt a "Brace, brace" command to a bunch of people who will probably not understand the rapid-fire noise anyway. It would obviously be beneficial to have done so but I suspect many crew would've suddenly found themselves in a state of task-saturation and be focussing on the real job. Not much point in warning pople if it costs the opportunity to maintain control of the aircraft.
• There is only one final approach per runway, therefore the aircraft was on short final, not finals.

Three final points:

1. Nothing conclusive about the cause of the event can be determined form the photographs.

2. The majority of idiotic posts here is something I try to laugh at but somehow I just can't quite.

3. And finally, may I add that ATC had runway 27L back in use for intersection departures within a very short space of time, considering - about 90min or so, possibly less. Meanwhile they dealt very successfully and professionally with a vast number of movements and only one runway at times, in addition to weather (more closures not long after re-opening the field) and the late discovery that the runway edge lighting was unserviceable, with last light not far away.

A big well-done to the ATC crowd at London Heathrow. Well done, guys...!!

[woodpecker]

Thanks "Fg Off Max Stout" for quoting my comments following your statement..

God help us! Never before have I seen so much uninformed bull being spouted.

If you know Heathrow you would know where the approach picture was taken from. Are you saying the second and third pictures of the touchdown and evacuation are not of "MM", of course not. So why with the "fortunate" photographer there at the time with his camera at the ready would he not "snap" a 777 far too low at a greater attitude than normal?

Of course the picture is correct.

If, however you were agreeing with my comments and disagreeing with those that followed then I apologise.

The six years that I flew the B777 never had a FADEC failure, but as you know FADEC as such doesn't exist so perhaps I should have said EEC failures!!

[Flap 5]

Having read through (most of) the thread there is some good information here as well as some rubbish. I am not 777 qualified being just a humble A330 / A320 / B737 pilot however there may be one item which has not been considered. If both engines had failed and were windmilling they would produce considerable drag (having large fans), increasing the glide angle and losing more energy than if the engines were under idle power.

[Fg Off Max Stout]

Woodpecker don't worry, your points seem undisputable. I merely juxtaposed your quote with a quote from the following post to illustrate the absurdity of these threads. Your post answered a question that was then asked by the following poster. Clearly he had launched in with his own opinions without reading any of the preceding thread, not even the post immediately before his own. This is why these threads will go around in circles until they implode, taking everyone's sanity with them.

Fortunately many of the less 'highbrow' posts in this thread have been, quite literally, pruned.

[sevenstrokeroll]

no fuel like an old fuel

ok

there was fuel on the plane, in the plane, in the tanks. I don't doubt that.

No one has yet to use the word: starvation, instead of exhaustion.

I don't even believe that it was starvation or exhaustion...but we can have fuel leaking all over the place, and it might not have gotten to the engines.

again, I don't think that is what happened. But at least let us use the right terms.

exhaustion: no more fuel period (useable)

starvation: fuel on board, but not getting to the engines.

[skol]

I havre to say after all this time, considering the aircraft was parked intact almost outside the hangar that as above, speculation will become worse as time goes on and that investigators must know the cause of the accident now.
More knowledgable SLF, especially frequent flyers will be avoiding 777's.
Some have noted that there was fuel in the tanks but there will always be some unusable fuel. The procedures for the type I fly (744) states in the notes for EICAS msg Fuel Qty Low, "Avoid high nose up attitude and excessive acceleration and deceleration".

[Croqueteer]

I hate to bring this up as a mere Quadrapuff pilot, (Retired) and I admit to not having seen every entry to this thread, but when presumably the auto pilot tried to follow the G/S, a pretty quick speed decay would be seen, which I would react to by disconnecting the autopilot and lowering the nose. This would allow some alfa left to arrest the rate of sink, which must have been excessive to stuff the gear through the wing. It would also possibly give another couple of hundred yards to the touchdown point. I say this as over the years I have been close to some total engine failures which have had successful outcomes ( No fatalities) due to the crew keeping the aircraft under control and landing with flying speed.

[Lost in Saigon]

Surely the most probable cause that can be deduced from the available information is that the engines were on straight feed and whilst there was fuel remaining it was asymetric - all on one side. Thus one engine was starved and ran down at about 600 feet.

You now have a heavy twin, gear down, one engine out, landing flap already selected, approaching at Vref plus a bit and two miles to the threshold.

what on earth do you think is going to happen next?

What happens next? Easy......

You call "Go Around, Flap 20", followed by "Positive Rate", and then "Gear Up".

Then you monitor the autopilot while the B777 merrily starts climbing away on one BIG FAT ENGINE! (110,000 lbs thrust)

OR.....

Add just a little bit of thrust to the good engine and land.

[HarryMann]

1 degree nose down (less than you could detect in a picture) from the 600' where the problem starts = impact 1NM short... They got to well less than 1/2NM short... so I am not sure your "they should have lowered the nose" is exactly what the AAIB will write about

Wrong Nigel ...

Not only have you got your sums wrong (1 deg over 1nm is almost exactly 100 ft in altitude), you also have the theory wrong too, as the actual glide angle would like as not improve if you're already on the back of the drag curve... which again, like as not, they were by then.

Your 1001st post doesn't exactly augur well for the future of considered and knowledgeable comment here

[mbd]

Quote:
The investigation is now focussed.. ..examining the range of aircraft systems that could influence engine operation.

I'm sure B777 pilots are sleeping well tonight.

Quote:
Following further demands for increased thrust.. ..the engines similarly failed to respond.

Lack of fuel will do that. Like I said it is all speculation, but what is most likely?


Quote "The real answer to that question is why don't you become a pilot and find out? "

Cheap shot, you really shouldn't jump to conclusions now should you?

[NSEU]

Just to show you how complex a system it is, I have included a description of the B777 EEC System with General Electric engines: (note: BA 777's have RR Trent engines, but they are probably similar)

Electronic Engine Control (EEC)

Each EEC has full authority over engine operation. The EEC uses thrust lever inputs to automatically control forward thrust and reverse thrust. The EEC has two control modes: normal and alternate. In both normal and alternate modes, the EEC uses N1 RPM as the parameter for setting thrust.

Probably similar, but not Trents use EPR as the primary parameter.

Sorry, I couldn't read the rest.. the red print is too hard on the eyes....

[Wayne Ker]

I think there has been enough chit chat about this incident, people are getting more and more extreme with wild ideas about what did or didnt happen. The AAIB have got an almost pristine aircraft to pick over, no fire etc to muddy the waters, I should think for them, it will be fairly straight forward to gather the facts.

I know it is asking the impossible but why don't we wait until the report is out and give the crew of the aircraft a bit of space to breath and recoup. We do not have the facts and wild speculation is no good for anybody.

[sky9]

Some interesting photographs from flightglobal
[URL="http://www.flightglobal.com/AirSpace/photos/baboeing777accident/ba_2D00_boeing_2D00_777_2D00_incident_2D00_at_2D00_heathrow-8122.aspx"]

[borghha]

Just a SLF here, but a long standing PPrune reader.

It struck me that the FAA report and AD on the 777 EPR sensing probes and - lines (GE engines, ok) almost predicted this crash. ('could lead to loss of control of the a/c in a critical flight phase') - Does anybody know whether RR engines are that different in this respect? Someone wrote that other engine manufacturers would 'look away' when such an AD goes out... I can hardly believe that, given the stakes. Wouldn't they have checked whether their probes/sensors were vulnerable (icing) in that respect too?

Fly safely.

[7x7]

Haven't read all 18 pages, so apologies if this point has been covered already, but can I have a quick show of hands to see how many captains out there would allow their FO - however experienced - to continue flying the approach and landing in a situation like this?

600' is 2 miles out. I don't think I'd be mentally capable of sitting back and continuing my PNF duties (or whatever it is BA with their rather unique system of PF/PNF call it). You're the captain, and if he doesn't do it exactly the way you want it done, in a no power situation like that, there's no recovering whatever his (in your mind) not quite appropriate actions might have lost you.