British Airways 777 I throught you filled the TANK !!!

[graham]

On my old Hyndia I have a very basic fuel gauge Now I know its a bit early to really know what happened but based on the the following ideas Bejking to Heathrow is just abot at the limit of a B777 range and there was no fire and this sort of problem ie the engines stopping in mid flight, I suspect that there may have been some fuel mismanagement or fuel aagement capactiy misreading

Graham Murdoch

[Yamato1701]

Well better to have had a full fuel load than what happened to an Air Canada 767 some years back. apparently that flight, Through a major math error, had only half the fuel necessary ended up gliding safely onto a racetrack in alberta

[Werner]

I wonder if maybe the fuel loaded in Beijing was contaminated with a quantity of water, or if the crew pumped fuel away from the tank in use to another set of tanks.

[phil gollin]

The latest info (STILL NOT DEFINITIVE) is that there was a problem with the engines not responding to the auto-throttles or manual throttles.

Why or how or whatever ??? - no reasons or theories so far advanced.

The AAIB is due to give an initial report by 48 hours after the crash (mid-day tomorrow), but it is unlikely to give anything other than the facts so far found - reasons will have to wait.

.

[Werner]

The data recorder indicates both the flight computer and the pilot requested more thrust from the engine, but the engines did not respond as ordered. I imagine the flight deck instruments failed when the generators were no longer powered sufficiently to supply them.

Since the engine controls are multiple independent systems, I suspect a simpler, shared resource, such as the fuel tanks.

I wonder what a pool of water in the fuel tank would do in a twelve hour transpolar flight with air temperatures around -80C

[chuck]

The data recorder indicates both the flight computer and the pilot requested more thrust from the engine, but the engines did not respond as ordered. I imagine the flight deck instruments failed when the generators were no longer powered sufficiently to supply them.

Since the engine controls are multiple independent systems, I suspect a simpler, shared resource, such as the fuel tanks.

I wonder what a pool of water in the fuel tank would do in a twelve hour transpolar flight with air temperatures around -80C

Power to the electrical systems will be supplied as long as the engine turns, and the engine will continue to turn even if out of fuel just from wind milling effect. If the engine is fuel starved, the flight electronics will record an engine stall.

[phil gollin]

For some proper info one really needs to look at something like the PPRUNE site which has a thread on this subject.

The Initial AAIB report does NOT state what actually failed - merely that the engines failed to respond.

The actual status of the engines, electirical system, fuel system and emergency power features have NOT been confirmed.

There is SPECULATION that one engine was not turning appreciably by the time it hit the ground (based upon lack of damage to front turbine tips which would otherwise have hit the distorted containment ring). For the other engine the visual evidence is equivical.

There have been quotes (NOT DEFINITIVE) that there was a power failure prior to the actual crash, but none of the passengers who were interviewed mentioned that.

There is lots of data already available to the investigators, a sophisticated multi-channel "black-box" data recorder, the "black box" cockpit voice recorder, and most probably the BA standard cockpit video recording.

The speculation is rather pointless as the facts released are abysmally small (VERY BAD PR from BA/BAA in my opinion) but because so few facts have been released the speculation will continue.

.

[chuck]

If the "power" failure refers to failure of engine thrust rather than that electrical supply, why would passengers perceive it?

[chuck]

A significant amount of fuel leaked from the aircraft but there was no fire

So there is likely no complete fuel exhaustion. Perhaps the flight electronics incorrectly shut off the fuel system? If the engine was hot, turning and receiving fuel when the crash occurred, it would start some fire?

[RickF]

It is a bit premature to speculate on the cause of the engine failure, if indeed there was one, but in the event of an electrical supply failure it is normal for an auxilliary power unit (APU) to fire up automatically. This is the generator that provides power on the ground when the engines are not running. If the APU fails a Ram Air Turbine is deployed in the slipstream and provides sufficient power for essential services.

Rick

[Werner]

A significant amount of fuel leaked from the aircraft but there was no fire

So there is likely no complete fuel exhaustion. Perhaps the flight electronics incorrectly shut off the fuel system? If the engine was hot, turning and receiving fuel when the crash occurred, it would start some fire?

Unless the fuel was highly contaminated. The fact that it didn't burn is strange....

[ARH]

With the amount of damage to the wing section, im surprised there was no fire,

[Werner]

Sloppy quality assurance at the Beijing fuel depot?

[chuck]

Sloppy quality assurance at the Beijing fuel depot?

There have been other cases where partially fueled aircraft suffered similarly spectacular crash landing damage, including main gear punching up through the wing as is the case here, but no fire.

Does anyone know if B777 uses central point refueling and use internal distribution to allocate fuel to different tanks? or are the tanks filled separately from different refueling points? If the fuel is filled centrally, than whatever fuel quality problem there is, it would homogenized to all tanks aboard, and in that case it would be quite amazing if the homogenized fuel quality could prove adequate to keep the engines operating without problems for 99% of a flight half way around the world, and then cause both engines to fail within seconds of each other.

Beijing is a major airport and presumably support a large number of long distance flights out of the same depot. if there is major quality control problem at the fuel depot, the problem would presumably not be confined to this aircraft, and long distance flights originating from Beijing would be falling left and right.

[Werner]

Fuel is no more or less likely than a failure in a multiple redundent system that has flown for perhaps a few thousand flight-years since the 777 was introduced.

The fact that 90% or so of all airplane crashes are human failures makes me suspicious.

[JPH]

Fuel is no more or less likely than a failure in a multiple redundent system that has flown for perhaps a few thousand flight-years since the 777 was introduced.

The fact that 90% or so of all airplane crashes are human failures makes me suspicious.

Yep.

We have systems at play here with multiple redudancy contigencies built in. The fact that the engines allegedly didn't respond should not have been a surprise to the flight crew as one or more of the built in redundancy safeguards would have alerted them to this alleged failure prior to the auto throttle, requesting engine throttle up. It is all a bit merky right now.

What interests me is that B.A came straight out & praised the flight crew. Do they know something we don't? If it is realised the crew made mistakes then B.A would have mud on their face & that would be something they would try to avoid at all costs, especially now. Interesting.

For me right now & until such time as the relevent facts are produced I am sitting on the fence.

[RNfanDan]

It's Bush's fault. He secretly approved a back-room deal with the Chinese to allow all their leaded toy paint to be disposed of by mixing into aircraft fuel supplies.

[JPH]

It's Bush's fault. He secretly approved a back-room deal with the Chinese to allow all their leaded toy paint to be disposed of by mixing into aircraft fuel supplies.

Thats all we need, more rumour & innuendo.................................................I like it.

[chuck]

Fuel is no more or less likely than a failure in a multiple redundent system that has flown for perhaps a few thousand flight-years since the 777 was introduced.

Really?, have you quantified the probability of various failure scenarios can account for the available evidence?

[chuck]

It's Bush's fault. He secretly approved a back-room deal with the Chinese to allow all their leaded toy paint to be disposed of by mixing into aircraft fuel supplies.

If I may borrow Werner's words:

"Evil doing by Bush in this case is no more or less likely than a failure in a multiple redundent system that has flown for perhaps a few thousand flight-years since the 777 was introduced".