AAIB initial report out on BA B777 crash at LHR
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Continuous descent approaches are the norm these days.
While CDAs may be the norm at LHR and elsewhere in Europe, they are NOT the norm in the US and Asia.
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We will get a preliminary report quite soon
As no answer publicly known - why allow similar a/c to fly ?
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Happy Biker: You are probably right, but I was there when they pulled the airplane out of the water and they found that the only place that had water damage was the first class carpet. Even the electrical bay was dry and that had been underwater the entire time.
The salvage company bought the wreck from the insurers and made all their money back selling the landing gear alone. Everything else was jam.
The airplane was just weeks old and very tight.
The Air France 744 that stuck its nose in the drink in Papeete was saved, and it had more water damage than the CI one.
If the 777 is as tough as the 744 it can take anything you dish out.
Unless you work for CI or KE (or of course SQ).
I forgot that KE lost a 744 in a crosswind landing incident that stressed the hull so bad it could not be straightened out so they cut it up for scrap. Another almost-new airplane. That makes three hull losses, only one with fatalities.
The salvage company bought the wreck from the insurers and made all their money back selling the landing gear alone. Everything else was jam.
The airplane was just weeks old and very tight.
The Air France 744 that stuck its nose in the drink in Papeete was saved, and it had more water damage than the CI one.
If the 777 is as tough as the 744 it can take anything you dish out.
Unless you work for CI or KE (or of course SQ).
I forgot that KE lost a 744 in a crosswind landing incident that stressed the hull so bad it could not be straightened out so they cut it up for scrap. Another almost-new airplane. That makes three hull losses, only one with fatalities.
Last edited by boofhead; 21st Jan 2008 at 21:47.
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A question:
If thrust was allowed to decay over a period of time to ~<30% N1, what might one expect to be the lag in time between an A/T or manual command for more thrust and the engines responding? Is this lag likely to be 5 seconds, 10 seconds, longer?
If thrust was allowed to decay over a period of time to ~<30% N1, what might one expect to be the lag in time between an A/T or manual command for more thrust and the engines responding? Is this lag likely to be 5 seconds, 10 seconds, longer?
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Afew thoughts on the speculation:-
Contaminated fuel - there was in incident of fuel contamination out of Lagos during the 90's. 4 aircraft were affected, 3 northbound and 1 southbound. The indications were of fuel filter blockage and not all the engines suffered at the same time, so I think it is an unlikely situation for the BA 038.
Fuel icing -as the fuel would be configured tank-to-engine, unlikely that both engines would suffer loss of thrust at the same time and surely the engines would 'cough and splutter' or surge?
Fuel starvation by configuring both engines to one tank -the AAIB has not indicated in it's interim report that a lack of fuel was found in either main tank, so again, and given BA's SOP'S, unlikely.
Pilot error in shutting off both fuel control levers during the approach - very, very unlikely.
Software glitch -perhaps due to condensation? Maybe not just due to condensation, but perhaps that one-in-a-billion statistic?
My money is on an electronic fault between throttle and engine.
Airframe by Boeing
Engines by Rolls-Royce
Micro-chips by Sum Ting Wong Electronics Ltd.
Contaminated fuel - there was in incident of fuel contamination out of Lagos during the 90's. 4 aircraft were affected, 3 northbound and 1 southbound. The indications were of fuel filter blockage and not all the engines suffered at the same time, so I think it is an unlikely situation for the BA 038.
Fuel icing -as the fuel would be configured tank-to-engine, unlikely that both engines would suffer loss of thrust at the same time and surely the engines would 'cough and splutter' or surge?
Fuel starvation by configuring both engines to one tank -the AAIB has not indicated in it's interim report that a lack of fuel was found in either main tank, so again, and given BA's SOP'S, unlikely.
Pilot error in shutting off both fuel control levers during the approach - very, very unlikely.
Software glitch -perhaps due to condensation? Maybe not just due to condensation, but perhaps that one-in-a-billion statistic?
My money is on an electronic fault between throttle and engine.
Airframe by Boeing
Engines by Rolls-Royce
Micro-chips by Sum Ting Wong Electronics Ltd.
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GB
Aviate, Navigate, Communicate!
Always in that order, faced with a potentially catastrophic situation as this the first rule of business is to fly the aeroplane.
Aviate, Navigate, Communicate!
Always in that order, faced with a potentially catastrophic situation as this the first rule of business is to fly the aeroplane.
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The first thing we learn at IFALPA about Accident Investigation is to abstain from speculation. The investigators in this case have all the evidence and the recorders in good shape at their disposal. We will get a preliminary report quite soon. As profesionals we should keep our twitchy fingers off the keyboards.
Let us respect our colleagues who did a wonderful job. The MOST IMPORTANT fact is there was NO LOSS OF LIFE.
Anyway, apart from a redirecting link to the forthcoming AAIB report, what is the purpose of any post on this thread/site if there is not an element of speculation involved?
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The RAT will operate at all airspeeds and altitudes. If it can't maintain RPM it will load shed and the main battery will assume the load. The RAT produces AC which is then converted to DC through two seperate TRU's. It also produces Hyd. power to the Center system which has priority over the electrical. Doubt if any of this info has any bearing on the accident.
I'm clueless?
I'm clueless?
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questions for ppruners
I have been informed by a source that the a/c did not run out of fuel. How much was in the tanks? I have not been able to find any official mention of this ..has anyone seen the figures or is this speculation.
Could a cup of coffee in the throttle area cause such a failure or would it at least leave the engines running but perhaps affect throttle response. The Fadecs are separate and would not in usch a circumstance shut the engines down...might alter power but surely not stop? I am always inistent that drinks go over my shoulder away from the panel just in case and in fact though that is the brief they often forget.
You would expect fuel contam to have affected more than one a/c as ha happened before and then earlier in the trip. The tanks usually mix the fuel well enough , so would the problem have occurred much earlier?
The temp on the day was plus 8...too high for icing ???especially at this stage of the flight. Would you say its still likely at that temp.
The engines seem to have stopped in a staggered fashion the left seems to have been rotating more than the right. what does this indicate?
what are your feelings
Could a cup of coffee in the throttle area cause such a failure or would it at least leave the engines running but perhaps affect throttle response. The Fadecs are separate and would not in usch a circumstance shut the engines down...might alter power but surely not stop? I am always inistent that drinks go over my shoulder away from the panel just in case and in fact though that is the brief they often forget.
You would expect fuel contam to have affected more than one a/c as ha happened before and then earlier in the trip. The tanks usually mix the fuel well enough , so would the problem have occurred much earlier?
The temp on the day was plus 8...too high for icing ???especially at this stage of the flight. Would you say its still likely at that temp.
The engines seem to have stopped in a staggered fashion the left seems to have been rotating more than the right. what does this indicate?
what are your feelings
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Gents, please recall that when you select flaps 25 in the beast Approach Idle is automatically selected. There are several other parameters for this selection but none the less this should give you a fairly rapid spool up in the event of a rejected approach or landing. It is deselected after touchdown where it goes back into Minimum idle.
Still Clueless
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Fuel Contamination Theory
If the fuel came from a contaminated source in Beijing I would have thought that it was likely that one or more aircraft could have used that same contaminated fuel source and sufferred engine malfunctions as a consequence?
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According to FLIGHT INTERNATIONAL
Having read the article in todays Flight International, it appears that:-
The Gear was deployed later than normal (according to a Tower Controller)!
Surely gear is usually taken by about 4 miles when slowing from 160 kts? If gear selection was left later than this, were the crew already experiencing problems well before 600 ft?
Anyway whatever the cause, a sterling job done by all involved!
WS
The Gear was deployed later than normal (according to a Tower Controller)!
Surely gear is usually taken by about 4 miles when slowing from 160 kts? If gear selection was left later than this, were the crew already experiencing problems well before 600 ft?
Anyway whatever the cause, a sterling job done by all involved!
WS
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Bilderberger says:
.
The preliminary report, first post in this thread, says
Then you say:
that sounds like the scenario in the film Fate is the Hunter" [/url]http://en.wikipedia.org/wiki/Fate_Is_the_Hunter_(film)[/url] which I understand was shown recently, with the plot line
I have been informed by a source that the a/c did not run out of fuel. How much was in the tanks? I have not been able to find any official mention of this ..has anyone seen the figures or is this speculation
The preliminary report, first post in this thread, says
A significant amount of fuel leaked from the aircraft but there was no fire.
Could a cup of coffee in the throttle area cause such a failure
Eventually a test flight re-creating the actual flight shows that the the crash was caused by a cup of coffee spilling and shorting out critical wiring
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Please, please read the thread before posting
I would respectfully ask that people read through both this and the previous (now closed) thread for answers to their questions before posting them. From watching this (originally very promising) thread develop it is apparent that people are sometimes not reading anything but the current page before posing an already answered question. Inevitably the thread will become an overly long rambling monster with little or no valuable input.
There seem to be some truly knowledgable people on here, and I for one, value their opinion, and enjoy reading their posts, but I'm sure they will eventually tire of answering the same old questions time and again.
Maybe a Mod might be able to modify the very first post with a short Q and A list to eliminate the need for people to read the whole 12 pages? Then if their question has already been answered they can be directed to the first page for info? (I realise this is cheeky coming from a newbie, sorry).
There seem to be some truly knowledgable people on here, and I for one, value their opinion, and enjoy reading their posts, but I'm sure they will eventually tire of answering the same old questions time and again.
Maybe a Mod might be able to modify the very first post with a short Q and A list to eliminate the need for people to read the whole 12 pages? Then if their question has already been answered they can be directed to the first page for info? (I realise this is cheeky coming from a newbie, sorry).
Nemo Me Impune Lacessit
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In 1989/92 I was flying a CFM engined B767-300ER and that had, for a while, a disconcerting feature whereby when making an MCP or TOGA selection that required more thrust, sometime only one lever would move forward, sometimes neither and a quick handful was required. A bit hazy now but I believe it was due to the grease on the throttle cable near the hot part of the engine losing its viscosity, eventually the problem was cured by changing the grease, ISTR. We were all aware of the problem and guarded the throttles very carefully.
BB,
Have a look at the engineers site airmech there was apparently 8000 kgs of fuel. I doubt whether coffee could penetrate the conformal coating of pcb's and the like, unless they are overheated. Let's all accept the AAIB initial report, they are looking at the reasons for the apparent electronic control of both engines not increasing thrust when demanded. If that has been eliminated I am sure they would have made a statement by now. My concern is that whatever caused this incident may not have been recorded in the FDR because the relevant parameters have not been included.
Have a look at the engineers site airmech there was apparently 8000 kgs of fuel. I doubt whether coffee could penetrate the conformal coating of pcb's and the like, unless they are overheated. Let's all accept the AAIB initial report, they are looking at the reasons for the apparent electronic control of both engines not increasing thrust when demanded. If that has been eliminated I am sure they would have made a statement by now. My concern is that whatever caused this incident may not have been recorded in the FDR because the relevant parameters have not been included.
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Having read all the posts again, the only one really is relevant in all the speculation... valipilot explains it very well....
Ignore the A/T.. 2 servos that drive the throttles. The throttles were pushed forward manually which overrides whatever a/t position was commanded. The TLA's (resolvers mechanically connected to the throttles and powered by the EEC's) send the EEC's commanded position.. forget autoflight/throttle the throttle position commands the relevant fuel flow/ EPR (it's not like Airbus).
No one knows (other than the AIB and the crew) whether the engines were running on touchdown, the only conceivable way if not is both master levers off (highly unlikely) or coffee spillage in the switches as a posibility (but again not very likely). If NAI had not been selected, again there would be handling problems and signs of surging/ EGT fluctuations when icing became apparent
If they were stuck in idle then it's EEC's controlling this.. rev unstowed would cause it but a dual failure again very unlikely so again it goes back to software.. an aircraft system input to the EEC's or EEC algorythem demanding min idle. Aircraft system interfaces generally demand more fuel, ie ECS demands, anti ice, flap position so unless there's been an electrical spike down a databus or dicrete line in then this can be ruled out.
Fuel contamination / icing could cause engine problems but you would expect somekind of surging or engine control problems earlier and most probably fuel filer bypass EICAS warning, not just not responding at idle. The heat management system (FCOC/ oil heat exchanger) preheats the fuel to prevent fuel waxing on the engine to prevent FMU torque motor problems.
EMI interference is another remote possibilty but then again i've used company mobiles during turnrounds and engine runs and they never even make the lcd's blink let alone interact with the current couplers!
Either way the flight crew had no time to troubleshoot or even work out whats going on so forget gliding angles, flap position and gear up/down and just commend them on bringing the airframe to a halt with no loss of life.
Ignore the A/T.. 2 servos that drive the throttles. The throttles were pushed forward manually which overrides whatever a/t position was commanded. The TLA's (resolvers mechanically connected to the throttles and powered by the EEC's) send the EEC's commanded position.. forget autoflight/throttle the throttle position commands the relevant fuel flow/ EPR (it's not like Airbus).
No one knows (other than the AIB and the crew) whether the engines were running on touchdown, the only conceivable way if not is both master levers off (highly unlikely) or coffee spillage in the switches as a posibility (but again not very likely). If NAI had not been selected, again there would be handling problems and signs of surging/ EGT fluctuations when icing became apparent
If they were stuck in idle then it's EEC's controlling this.. rev unstowed would cause it but a dual failure again very unlikely so again it goes back to software.. an aircraft system input to the EEC's or EEC algorythem demanding min idle. Aircraft system interfaces generally demand more fuel, ie ECS demands, anti ice, flap position so unless there's been an electrical spike down a databus or dicrete line in then this can be ruled out.
Fuel contamination / icing could cause engine problems but you would expect somekind of surging or engine control problems earlier and most probably fuel filer bypass EICAS warning, not just not responding at idle. The heat management system (FCOC/ oil heat exchanger) preheats the fuel to prevent fuel waxing on the engine to prevent FMU torque motor problems.
EMI interference is another remote possibilty but then again i've used company mobiles during turnrounds and engine runs and they never even make the lcd's blink let alone interact with the current couplers!
Either way the flight crew had no time to troubleshoot or even work out whats going on so forget gliding angles, flap position and gear up/down and just commend them on bringing the airframe to a halt with no loss of life.
parabellum
A CFM powered B763 would struggle to get airborne - I believe that you mean a GE powered B763.
My understanding is that the B777 has an autothrottle for each engine which means that you have the assistance of an autothrottle during engine out manoeuves. It is considerably different to the B767 system.
My understanding is that the B777 has an autothrottle for each engine which means that you have the assistance of an autothrottle during engine out manoeuves. It is considerably different to the B767 system.