BA B777 Incident @ Heathrow (merged)
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SLF here....could someone please tell me if 600 ft 2 miles out is standard? Seems pretty low.
It's a shame some folks here get their blood pressure up over another person's comments. Yes, opinions are like a$$holes and everyone has one. No need to be blasting, just ignore and look away.
Am still applauding the crew
and mourning the loss of the 777. What a pity. 
C of F
It's a shame some folks here get their blood pressure up over another person's comments. Yes, opinions are like a$$holes and everyone has one. No need to be blasting, just ignore and look away.
Am still applauding the crew
and mourning the loss of the 777. What a pity. C of F
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I cannot imagine another profession/industry where such uninformed nonsense is pedaled in public.
As a rough estimate, more than 50% of respondents who look like professionals' and quote facts, are so inept and wide of the mark, that they show their professional and industry in a very poor light. This can do nothing more than give the press on this forum the impression that there sporadic and patchy training and no SOP's.
I really don't know why people get so torqued up; the title says "Rumour Network" not "Professional Pilots Accident Investigation Board". Especially at such an early stage one expects rumours and confusion. And even if much of what is suggested is wrong in a given case, it may no be wrong in terms of a topic to think of. For example, fuel starvation may have nothing to do with this accident - but how many people thought a little bit more about their fuel load today, I wonder ....
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the title says "Rumour Network" not "Professional Pilots Accident Investigation Board"
The delightful thing about PPRuNe is that you can talk quite freely about the aviation world around you, as you see it. This is not an educational site per-sée (sp?)
Rubbish should be pointed out by all, but for the rest it's a free for (within reason) all.
Keep it up folks (and Danny)
IFTB
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FADEC failure?
pavvyben - I don't think FADEC failure is likely, as there appears to have been a possible common-mode failure affecting the ability of BOTH engines to respond to throttle demands, and the FADECs on the two engines are functionally, electrically and physically independent.
Of course, it may not be a common-mode failure - failures of both FADECs occurring with a short time of each other are not impossible, just very unlikely.
JC
Of course, it may not be a common-mode failure - failures of both FADECs occurring with a short time of each other are not impossible, just very unlikely.
JC
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JS777
Thanks for that...
The "Safety Case" for any 2 (or more) engine aircraft is that it can afford a single engine failure for any of many causes. On takeoff, approach, cruise or whatever...
Your post implies, but I am sure is a "simplistic" view, that 1 system (AIMS) could, at a single "point", cause both engines to fail - despite 2 independant Thrust Levers (Throttles!). This would seem to me the "Safety Case" principle is in doubt
I fly what is known as the ultimate electric jet - A320 types... But, AFAIK, we do not have the equivalent of the AIMS, and that the 2 TLs essentially go to the 2 engines separately (I am sure, as with most things Airbus, I do not understand it completely!) i.e. to get a double engine failure, we require a double fault somewhere, which in probability terms is unlikely...
Any light you can shed on this aspect i.e. a single system (AIMS?) as a single "point" through which 2 x TL and ATHR control the gines would, errr, be "enlightening"
1.B777 is a fly by wire aircraft..it is not as simple as a wire to an engine..please
SYS involved include AIMS CMCS Arinc 629 OPAS FADEC
Throttle inputs go to an AIMS(Airplane Info Mngmnt Sys..and vice versa
Engine is managed by a dual channel FADEC system. The EEC is part of this system(the heart).
SYS involved include AIMS CMCS Arinc 629 OPAS FADEC
Throttle inputs go to an AIMS(Airplane Info Mngmnt Sys..and vice versa
Engine is managed by a dual channel FADEC system. The EEC is part of this system(the heart).
The "Safety Case" for any 2 (or more) engine aircraft is that it can afford a single engine failure for any of many causes. On takeoff, approach, cruise or whatever...
Your post implies, but I am sure is a "simplistic" view, that 1 system (AIMS) could, at a single "point", cause both engines to fail - despite 2 independant Thrust Levers (Throttles!). This would seem to me the "Safety Case" principle is in doubt
I fly what is known as the ultimate electric jet - A320 types... But, AFAIK, we do not have the equivalent of the AIMS, and that the 2 TLs essentially go to the 2 engines separately (I am sure, as with most things Airbus, I do not understand it completely!) i.e. to get a double engine failure, we require a double fault somewhere, which in probability terms is unlikely...
Any light you can shed on this aspect i.e. a single system (AIMS?) as a single "point" through which 2 x TL and ATHR control the gines would, errr, be "enlightening"
Kudos to AAIB, preliminary report got out very quickly. Everyone please do read it.
Whatever happened here, it seems that one-sixty till four saved the day. Good thing that established by 1000 is not the way to play at LHR.
Whatever happened here, it seems that one-sixty till four saved the day. Good thing that established by 1000 is not the way to play at LHR.
Last edited by Clandestino; 18th Jan 2008 at 22:21. Reason: removed the excessive
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SLF wants to play 20 questions
Sorry I'm too dense to keep up. A few questions:
1) Did the pilots deliberately put the plane down on the grass?
In the case of issues with the landing gear (as hinted in some unverified accounts) and/or they anticipated a stall and hard fall, perhaps the notion of a softer surface than tarmac might have some appeal.
2) Would the outcome, in retrospect, likely have been as fortunate had they landed (with same force) on the runway?
With the fuel spilling out, perhaps it was just as well they avoided the tarmac and a potential rain of sparks all over the place.
3) Was the stall-like nose up movement at the very end as seen in the video intentional or an unwanted consequence of whatever failures the aircraft suffered?
4) If intentional, what was the purpose of it, assuming the angle of attack was higher than it should have been for a smooth landing, as appeared to be the case to my untrained eyes?
5) It is generally not entirely unreasonable to assume that the timing of the failure was crucial? A little shift in time and they either fall down in the residential area or make a reasonably normal landing.
There, I've proven that I have no clue how these flying cans work, my apologies for interrupting your discussion. My reasoning above comes from a lifetime of never flying a plan. Just trying to get a grasp on some basics and perhaps understand how fortunate the outcome really was.
1) Did the pilots deliberately put the plane down on the grass?
In the case of issues with the landing gear (as hinted in some unverified accounts) and/or they anticipated a stall and hard fall, perhaps the notion of a softer surface than tarmac might have some appeal.
2) Would the outcome, in retrospect, likely have been as fortunate had they landed (with same force) on the runway?
With the fuel spilling out, perhaps it was just as well they avoided the tarmac and a potential rain of sparks all over the place.
3) Was the stall-like nose up movement at the very end as seen in the video intentional or an unwanted consequence of whatever failures the aircraft suffered?
4) If intentional, what was the purpose of it, assuming the angle of attack was higher than it should have been for a smooth landing, as appeared to be the case to my untrained eyes?
5) It is generally not entirely unreasonable to assume that the timing of the failure was crucial? A little shift in time and they either fall down in the residential area or make a reasonably normal landing.
There, I've proven that I have no clue how these flying cans work, my apologies for interrupting your discussion. My reasoning above comes from a lifetime of never flying a plan. Just trying to get a grasp on some basics and perhaps understand how fortunate the outcome really was.
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Mad,
we'll have to agree to disagree.
Your comments are aimed at the comments from amateurs on this forum, and you are right.
I'm concerned at the number of professionals (just check the profiles) who make incorrect or unprofessional assertions.
This isnt just any old group of chaps(ess') down the pub, its the elite of the flying fora.
we'll have to agree to disagree.
Your comments are aimed at the comments from amateurs on this forum, and you are right.
I'm concerned at the number of professionals (just check the profiles) who make incorrect or unprofessional assertions.
This isnt just any old group of chaps(ess') down the pub, its the elite of the flying fora.
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RE: FADEC failure?
I don't think FADEC failure is likely, as there appears to have been a possible common-mode failure affecting the ability of BOTH engines to respond to throttle demands, and the FADECs on the two engines are functionally, electrically and physically independent.
And given the history of power supply disruption on B777 (see my previous post, referencing AAIB/SB/2007/2), I'd say that FADEC issues can neither be ruled in nor ruled out at this juncture.
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MM
Thanks for that... just to check, 1 system is for Eng #1, and one for #2 etc.... not 1 AIMS system for #1 and #2, with a backup AIMS to be engaged when? how?
Reventor
Your last point leads to the earlier... Where the aircraft got to i.e. ran out of altitude, at what speed, and at what "angle of attack", and related "rate of descent" are all fundamentally "linked" by pure physics. Given it seems thrust was fixed, the pilots' level of control was really related to balancing the other factors for the best possible outcome i.e. not being independantly "controlled".
As a pilot, and given what the AAIB said, I would say the combination of Angle of Attack, where it got to, speed it got there with etc. was pretty damn near "optimal" for survivability.... = I think they did bl**dy well
There air two independent AIMS systems (cabinets)
Reventor
Did the pilots deliberately put the plane down on the grass?
had they landed (with same force) on the runway?
Was the stall-like nose up movement
assuming the angle of attack was higher than it should have been for a smooth landing
There, I've proven that I have no clue how these flying cans work
As a pilot, and given what the AAIB said, I would say the combination of Angle of Attack, where it got to, speed it got there with etc. was pretty damn near "optimal" for survivability.... = I think they did bl**dy well
The early fbw airbus have a tape connector under the thrust levers.It looks like the tape that connected your Pentium 0 desktop to a very basic printer.
Perhaps the connector has been bridged or earthed to produce a corrupted or missing signal?
Perhaps the connector has been bridged or earthed to produce a corrupted or missing signal?
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Just a passing thought...
Why is the reference to AoA being made when it is impossible to tell the AoA just by looking at the plane?
AoA is the angle between the wind and the chord line. Not the angle between the chord line and the ground, which is infact pitch angle.
Why is the reference to AoA being made when it is impossible to tell the AoA just by looking at the plane?
AoA is the angle between the wind and the chord line. Not the angle between the chord line and the ground, which is infact pitch angle.
The early fbw airbus have a tape connector under the thrust levers.It looks like the tape that connected your Pentium 0 desktop to a very basic printer.
Perhaps the connector has been bridged or earthed to produce a corrupted or missing signal?
Perhaps the connector has been bridged or earthed to produce a corrupted or missing signal?
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RE: FADEC failure?
Bill.Martin - it is possible that there could have been a common-mode failure of the aircraft power supplies to the FADECs, but the FADEC's PRIMARY power sources are independent, dedicated, engine-mounted generators. A FADEC will only use aircraft power if its engine-mounted generator is incapable of supplying sufficient power, so common-mode loss of aircraft-supplied power would cause both engines to shut down only if both dedicated generators had also failed.
JC
JC
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One thing I don't get. At 600', to be stabilised on approach, the engines should have been above idle thrust. So the statement from the AAIB they failed to respond to an increase in demanded thrust is only half the story. If they continued to provide the level of thrust they were already at before the commanded increase, there's no way they should have landed 1000' short of the start of the runway. Moreover, it appears that No2 was barely rotating when it swallowed a bellyful of LHR's finest turf. I wonder how far out the problems really started, 2nm or quite a bit further?