BA Boeing 777 Crash Lands at LHR

[Murmur 3,941]

>It would take someone sitting in the cockpit putting their>fingers in their ears closing their eyes and going "la la la>la la la la la" for a low fuel prompt to go unnoticed VERY>early..Surprisingly enough as it may seem for some, the history of aviation safety reveals a lot of aviation accidents happened with pilots having clear and ample warnings beforehand.Marco

[mgh 89]

Initial findings of the AAIB are that both engines failed to respond to either auto-throttle or manual throttle commands.The AAIB has not yet determined why this happened.

[Guest majhankee]

How much fuel DO planes carry? Say, to get from Beijing to London, it took 500 gallons (using small numbers here). Do aircraft carry somewhere around 510 gallons or 550 gallons for safety?

[craig_read 43]

It depends on the run they are doing.. but typically they have a minimum amount of fuel for landing.. not counting any holding fuel or taxi fuel.. I imagine it's in the order of 10,000Kg for your minimum landing fuel.. then on top you have contingency.. taxi.. and anything else.. so if an aircraft is landing and hasn't had to hold.. and it's been clear all the way.. and it's on it's first approach.. you can bet it's got enough fuel for another hour or so flying around.. at least.. before it runs out..So .. Taxi + Contingency (45 min hold or so) + min landing fuel + flight plan fuel + initial taxi fuel... etc...So.. saying it might have ran out of fuel is just not realistic.CheersCraig

[G-SWSM 1]

Craig,"It would take someone sitting in the cockpit putting their fingers in their ears closing their eyes and going "la la la la la la la la" for a low fuel prompt to go unnoticed"I kid you not when I say that I practically wet myself when I read that, I thought it was just so blinking hilarious.I even started to build up a mental picture of two pilots doing just that, kind of like the scenario with the bored pilots racing,what a great comedy sketch that would make, "what do you mean we don't have enough fuel" yes but I only had

[michal 44]

>would take someone sitting in the cockpit putting their>fingers in their ears closing their eyes and going "la la la>la la la la la" for a low fuel prompt to go unnoticed VERY>early..Well, history of air crashes is full of accidents caused by pilots who almost did that - for one or other reson they did not pay much attention to warnings. Fuel exhaustion happened already 3-4 times in big commercial jet aircraft and hundreds of times in GA flying, so lets remember that humans are capable of of all kind of mischief. So no, fuel exhaustion can't be discounted, not yet.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[scott967 62]

Per the British Authorities, it doesn't sound like any lack of fuel. They state the autothrottles were calling for an increase of power @ 600 ft, but the engines did not respond. Since this occurred on both engines, it implies a problem that would be common to both engines. I assume the engine to tank configuration is such that both engines probably weren't feeding from the same tank. Fuel quality could be an issue, though it isn't clear why it would be evidenced at this point in the flight. dual engine problem implies it isn't something like an hp fuel pump drive shaft failure, or main fuel control problem which it is hard to see would occur simultaneously on two engines. So we may be forced to look "upstream" at the control logic from the autothrottle (and the Authorities report pilots moving throttle levers, so also the engine control logic) to see where common-mode failures could occur. Once the FDR is decoded that should provide most of the data needed. Since the aircraft is intact, any suspect areas should be able to be tested, though that wouldn't rule out an intermittent error, or one based on a set of inputs that are difficult to test (and possibly aren't captured by the FDR, such as internal logic states of the various controls).scott s..

[KevinAu 441]

>>Well, history of air crashes is full of accidents caused by>pilots who almost did that - for one or other reson they did>not pay much attention to warnings. Fuel exhaustion happened>already 3-4 times in big commercial jet aircraft and hundreds>of times in GA flying, so lets remember that humans are>capable of of all kind of mischief. So no, fuel exhaustion>can't be discounted, not yet.>>Michael J.Sure, nothing should be discounted, but to say that both engines flamed out from fuel starvation on short final would be akin to saying alien spacecraft shot them down. The images and outcome from the incident does not add up to such a supposition. Like the alien scenario, possible, but very remote.If they did lose both engines at that low of an altitude, those people would all be dead. In the normal landing configuration and at the normal landing speed, if the engines both quit all of a sudden at that point, the plane would fall out of the sky. It would have been a very hard hit, most likely nose down. The plane would be smashed even if they hit main wheels first. We would not be here with a dozen or two cases of whiplash among the passengers.This looks more like the crash of the C-5 at Dover not too long ago, where the aircraft mushed into the ground with insufficient power to stay aloft. The more likely possibilities would be pilot error in failing to manage speed and power, an unrecognized loss of power in one of the engines, or most likely failure in the FADECs or the thrust levers. Since most modern aircraft with computer controlled engines do not actually have thrust levers that mechanically link to engines, a common failure scenario is loss of TL signal to the FADECs or EECs. If their TLs failed at a moment where they were throttled backed, the engines would have been stuck at that low power setting and there would be nothing they could do to adjust the power.

[craig_read 43]

Steve.Whehe.. I'm glad you appreciated my humour there.. Ryan, and All (I've been quiet on your forum lately lol)Yeah exactly.. that's what.. 6,000Kg.. slightly over.. That's got to be at or below min landing fuel and due to go arounds.. I think you could make an educated guess.. 8,000Kg - 10,000Kg min landing fuel.. maybe that again for your contingency.. so.. 16,000Kg to 20,000Kg.. and perhaps a couple more for good measure.. 18,000Kg to 22,000Kg.. something like that.. and if you expect a long taxi maybe even a bit more still.. I would be amazed if that aircraft had much less than 20,000Kg on board upon landing.. and you'd set the reserve to landing + maybe... 60% contingency, so that's about 12,800Kg to 16,000Kg.. 24,000lbs to 32,000lbs... That's probably a lot actually the later.. I am not entirely sure what the 777 uses.. But you can see what I mean.. I won't be a million miles away.. give or take a couple of 1,000lbs.. So it would chime INSUFFICENT FUEL (747 there.. but 777 won't be massively different in that respect) then.. and you know when you're getting close to burning half your real reserve up..NO WAY.. was that lack of fuel.. As for autothrottle.. I am not convinced of that either.. simple press on the yoke button.. and it's off.. and push forward on the throttles.. I'd probably expect him to have his hands there anyway ready to take over on the last couple of hundred.. and besides.. the pilot not flying would have seen the warning and sorted it in seconds.. you might lose a second or three.. and perhaps.. 4 or 5 knots.. easily recoverable.. and plenty of time to do a go around if you're not happy.. Maybe some electrical fault effecting the engine control units?I dunno.. but.. at this point in time I really would not like to speculate.. but.. at this time.. without more information..CheersCraig

[RFields5421 1]

There is nothing in the AAIB report that indicates or hints that the engines did not continue to provide power until impact. The report does not talk about the engines failing.Just that the Autothrottle and the pilots could not increase power.I'm just guessing here - but it appears common to me for the engines to add a bit of power as the last notch of flaps is dropped.I'm sure the control systems, software and such are going to get a real serious look.

[mgh 89]

As I reported earlier:"Initial findings of the AAIB are that both engines failed to respond to either auto-throttle or manual throttle commands."

[Guest nihongo]

>>It depends on the run they are doing.. but typically they>>have a minimum amount of fuel for landing.. not counting any>>holding fuel or taxi fuel.. I imagine it's in the order of>>10,000Kg for your minimum landing fuel.. then on top you>have>>contingency.. taxi.. and anything else.. so if an aircraft>is>>landing and hasn't had to hold.. and it's been clear all the>>way.. and it's on it's first approach.. you can bet it's got>>enough fuel for another hour or so flying around.. at>least..>>before it runs out..>>>>So .. Taxi + Contingency (45 min hold or so) + min landing>>fuel + flight plan fuel + initial taxi fuel... etc...>>>>So.. saying it might have ran out of fuel is just not>>realistic.>>>>Cheers>>>>Craig>>I asked my dad (777 captain) last night and he said he'd be>getting seriously worried somewhere around 12,000 lbs of fuel>remaining.Ask him for me if the 777 sensors tell him how much is remaining (or is there only a load sheet? I am not a 777 expert...)? I mean, we can rule this out that it is a fuel prob (I would not imagine it happening in this case, but the non-aviation 'experts' think it is!!!)

[Guest nihongo]

>Steve.W>>hehe.. I'm glad you appreciated my humour there.. >>>Ryan, and All (I've been quiet on your forum lately lol)>>Yeah exactly.. that's what.. 6,000Kg.. slightly over.. That's>got to be at or below min landing fuel and due to go arounds..>I think you could make an educated guess.. 8,000Kg - 10,000Kg>min landing fuel.. maybe that again for your contingency..>so.. 16,000Kg to 20,000Kg.. and perhaps a couple more for good>measure.. 18,000Kg to 22,000Kg.. something like that.. and if>you expect a long taxi maybe even a bit more still.. I would>be amazed if that aircraft had much less than 20,000Kg on>board upon landing.. and you'd set the reserve to landing +>maybe... 60% contingency, so that's about 12,800Kg to>16,000Kg.. 24,000lbs to 32,000lbs... That's probably a lot>actually the later.. I am not entirely sure what the 777>uses.. But you can see what I mean.. I won't be a million>miles away.. give or take a couple of 1,000lbs.. So it would>chime INSUFFICENT FUEL (747 there.. but 777 won't be massively>different in that respect) then.. and you know when you're>getting close to burning half your real reserve up..>>NO WAY.. was that lack of fuel.. As for autothrottle.. I am>not convinced of that either.. simple press on the yoke>button.. and it's off.. and push forward on the throttles..>I'd probably expect him to have his hands there anyway ready>to take over on the last couple of hundred.. and besides.. the>pilot not flying would have seen the warning and sorted it in>seconds.. you might lose a second or three.. and perhaps.. 4>or 5 knots.. easily recoverable.. and plenty of time to do a>go around if you're not happy.. Maybe some electrical fault>effecting the engine control units?>>I dunno.. but.. at this point in time I really would not like>to speculate.. but.. at this time.. without more>information..>>Cheers>>Craig45 minutes worth of fuel needs to be carried by the aircraft. This means that if a pilot lands inside this 45 minutes of minimum fuel, something has seriously gone wrong. The idea is to never use the 45 minutes of the fuel (minimum fuel at arrival). If this is part of a pilots discipline (if not an airline will not employ you!) it is called good Airmanship.So you need fuel depending on a sector. >1 Taxi (15 minutes) >2 Flight (variable on sector) >3 Holding (30 minutes?) >4 Alternate (variable) and then the >5 minimum landing fuel (which is the minimum as mentioned above). Add these together and calculate the amount of fuel required (also depending on wind conditions) for the flight. Sometimes there is a need for big jets to return to the gate for refuelling if taxi fuel time is more than 30 minutes (because amount usually held is 15 minutes, but if aircraft is idling then it can be part of it, I think), but a professional pilot may be able to answer this for me.http://f111raaf.blogspot.com/Keep the F111, Australia's BEST military (and heavy strike capable) aircraft.http://www.ausairpower.net/index.html

[Guest BarryM]

Hi All. New here and enjoying your discussion. I fly FSX, a few sizes and shapes of hang glider, got of lot of 707 simulator time while in the USAF years ago, and distant memories of single engine flying.I know nothing about the 777. The official report did say the engines failed to respond to pilot or autopilot input. If engine management is all digital, the symptoms could suggest a software error.Either that, or carburetor icing (power at idle, temperatures just above freezing, IFR approach through clouds and drizzle.) There's no mention of the pilot applying carburetor heat during the approach. :)

[Guest TomOOO]

HumI look forward to my flight into Heathrow tomorrow on a 777 fromNew Jersey. :) Might be lots of empty seats |Tom