BA B777 Incident @ Heathrow (merged)
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Originally Posted by Buster The Bear
The chap (engineer) interviewed by the BBC who spoke to the crew after this incident seems to have the 'known fact's' spot on!
As for the wild speculators on here...........
Do us all a favour would you? If your post could be started with the words 'I'm not a pilot/engineer/aviation professional' or include the phrases 'I'm no expert', 'I'm just guessing' or 'I'm assuming' don't bother. Click 'back' on your browser and go elsewhere.
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The general consensus seems to be that the crew did a good job. The 'favourite' explanations seem to be either wind-shear or some sort of complete power loss on short final.
No one though seems to have dared to suggest that actually this was simply a cocked up approach...similar to a particular MD11 in Hong Kong a few years ago...loss of airspeed followed by a high sink rate prior to touch down...in windy conditions but NOT wind-shear as the report decided. There doesn't have to have been a system failure for there to be a crash.
Trouble is as usual there are plenty of contradictions...the claim (from the captain apparently) that the plane lost all power and glided in just doesn't tally with lots of noise on approach and passengers not aware of anything until after touchdown.
No one though seems to have dared to suggest that actually this was simply a cocked up approach...similar to a particular MD11 in Hong Kong a few years ago...loss of airspeed followed by a high sink rate prior to touch down...in windy conditions but NOT wind-shear as the report decided. There doesn't have to have been a system failure for there to be a crash.
Trouble is as usual there are plenty of contradictions...the claim (from the captain apparently) that the plane lost all power and glided in just doesn't tally with lots of noise on approach and passengers not aware of anything until after touchdown.
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From the sun website:
"The plane narrowly missed Prime Minister Gordon Brown whose convoy was travelling on the airport’s perimeter road."
..............riiiiiiight
"The plane narrowly missed Prime Minister Gordon Brown whose convoy was travelling on the airport’s perimeter road."
..............riiiiiiight
todays best media excerpt for me
...camera focuses on 2 main gears, laying down on the grass....
'aviation expert' - "if im not mistaken, that appears to be part of the undercarriage"
actually, scratch that. my favourite quote......
"it will take some time for the information held on the FDR to be recovered, as it will have to be broken into. they are desgined to withstand extreme crashes"
or, they could just plug a laptop/flashcard in and do a download....or is that too simple?
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BA B777 Incident @ Heathrow
Hi
Perhaps a likely reason for two engines to fail (presumably near / or at the same time [only going from what I have read]) would be fuel starvation. Being at the end of the flight, this would seem at least a possible area. If it was unexpected (as it seems it was), it could have been faulty readings of fuel remaining and or / combination of an error in fuel loading somewhere along the line. Just thoughts out loud - most likely it will be something entirely different and a more complex series of events.... first time poster.
Regards
Jason
Perhaps a likely reason for two engines to fail (presumably near / or at the same time [only going from what I have read]) would be fuel starvation. Being at the end of the flight, this would seem at least a possible area. If it was unexpected (as it seems it was), it could have been faulty readings of fuel remaining and or / combination of an error in fuel loading somewhere along the line. Just thoughts out loud - most likely it will be something entirely different and a more complex series of events.... first time poster.
Regards
Jason
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A pilot's (albeit PPL) account of the approach:- http://video.google.com.au/videoplay...30773432754019
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Firstly, in 11 years of reading PPRUNE, ive never seen the server thrashed so much. How annoying is that server too busy message?
Anyways, i'm waiting with eager anticipation for the facts to emerge. From the facts I have seen so far I can't believe the conclusion I am led to.
1. Aircraft lands short but within airfield boundary, not on runway.
2. Incredibly short 'landing roll'.
3. Multiple passengers saying no word from flight deck.
This surely can only mean significant loss of power for some reason.
Aircraft only just makes it to the field and has very low forward speed on touch down.
I would be amazed if its windshear. I really can't see windshear powerful enough to do that to a 777 coming out of todays weather, you would need severe TS.
Fuel starvation is plausable but both engines on short final with no word to ATC beforehand? I cant see that either.
A lot of large birds would be needed to instantly and catastrophically shut down both donks at once so I can't see that either.
So we will see.
I'm raising a glass to Boeing for making such tough tractors.
Anyways, i'm waiting with eager anticipation for the facts to emerge. From the facts I have seen so far I can't believe the conclusion I am led to.
1. Aircraft lands short but within airfield boundary, not on runway.
2. Incredibly short 'landing roll'.
3. Multiple passengers saying no word from flight deck.
This surely can only mean significant loss of power for some reason.
Aircraft only just makes it to the field and has very low forward speed on touch down.
I would be amazed if its windshear. I really can't see windshear powerful enough to do that to a 777 coming out of todays weather, you would need severe TS.
Fuel starvation is plausable but both engines on short final with no word to ATC beforehand? I cant see that either.
A lot of large birds would be needed to instantly and catastrophically shut down both donks at once so I can't see that either.
So we will see.
I'm raising a glass to Boeing for making such tough tractors.
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Microburst
IN REPLY TO: "I would think that windshear is not very likely. Sure, there was "some" wind, no really windshear-like conditions. And what's more, the B777 has a so-called Predictive Windshear System. (PWS) The system is always operational during approach, using the advanced weather radar on board. It is also operating, and scanning for windshear, even if the flight crew has switched off the WX radar.
It will display windshear in ahead on the navigation display, and announce: "caution, windshear ahead" or "go-around, windhear ahead" depending on the severity. And IMHO windshear will not cause a double flame-out."
I suggest there was 'windshear-like' conditions, specifically those of a microburst. Yes the 777 should provide confirmation of windshear conditions, but windshear is incredibly difficult to forecast and identify and the system you refer to could only specifically trigger an alert once already in windshear conditions, by which time the recommended escape manoeuvre of full thrust and alpha to stick shaker would have to be employed. "And IMHO windshear will not cause a double flame-out." Your final point there demonstrates quite overtly your ignorance on the subject of windshear; the danger associated with windshear has absolutely nothing to do with an aircraft's engines, but the massive degradation it has on the lift of even the largest aircraft. It is quite probable the reason BA 777 landed short of the runway today was because it encountered microburst conditions on short finals.
It will display windshear in ahead on the navigation display, and announce: "caution, windshear ahead" or "go-around, windhear ahead" depending on the severity. And IMHO windshear will not cause a double flame-out."
I suggest there was 'windshear-like' conditions, specifically those of a microburst. Yes the 777 should provide confirmation of windshear conditions, but windshear is incredibly difficult to forecast and identify and the system you refer to could only specifically trigger an alert once already in windshear conditions, by which time the recommended escape manoeuvre of full thrust and alpha to stick shaker would have to be employed. "And IMHO windshear will not cause a double flame-out." Your final point there demonstrates quite overtly your ignorance on the subject of windshear; the danger associated with windshear has absolutely nothing to do with an aircraft's engines, but the massive degradation it has on the lift of even the largest aircraft. It is quite probable the reason BA 777 landed short of the runway today was because it encountered microburst conditions on short finals.
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27 Left
Luckily this has happened on 27 left.
The Wet grass saved all involved.
A of A was very high just over Hatton Cross, nose went suddenly up. I tend to believe they did it to stall the machine on grass at very slow speed nose up, rather than crash land on the hard dry asphalt.
I have seen a video and it looks like the plane went nose up and then stalled to finally touch down on the best available point located immediately after the fence/lights: this was the perfect ideal final gliding-landing on grass.
Same landing on asphalt would have been catastrophic.
It looks like they lost power, kept the plane perfectly aligned and decided to bring it down gliding on the grass.
They have done a fantastic job, but the total loss of power is difficult to digest, after so many hours of perfect engine performance, why total loss of power on final, I believe in only a few options:
-severe bird strike, in early approach
-severe wind shear, very final
-fuel starvation due to faulty gauges, in early approach
Flight was nearly 20 mins early, I do not think fuel could have all gone by 1240, ETA was 1300.
Wx was excellent compared to the previous days, but sudden windshear can always happen. Very rare to cause such a loss of speed but not impossible.
Bird strike could be also a possibility, but very rare.
I have been told gear was downed quite late, this could explain a gliding approach, with a final decision to land on the soft wet grass. If this is confirmed they are heros for ever, and then it was possibly a bird strike over Hounslow, or fuel starvation.
We will soon find out. They are all alive
...fuel starvation is not impossible, due to faulty gauges of course!
If it was wind shear instead, excellent handling on final. Soft landing on grass.
The Wet grass saved all involved.
A of A was very high just over Hatton Cross, nose went suddenly up. I tend to believe they did it to stall the machine on grass at very slow speed nose up, rather than crash land on the hard dry asphalt.
I have seen a video and it looks like the plane went nose up and then stalled to finally touch down on the best available point located immediately after the fence/lights: this was the perfect ideal final gliding-landing on grass.
Same landing on asphalt would have been catastrophic.
It looks like they lost power, kept the plane perfectly aligned and decided to bring it down gliding on the grass.
They have done a fantastic job, but the total loss of power is difficult to digest, after so many hours of perfect engine performance, why total loss of power on final, I believe in only a few options:
-severe bird strike, in early approach
-severe wind shear, very final
-fuel starvation due to faulty gauges, in early approach
Flight was nearly 20 mins early, I do not think fuel could have all gone by 1240, ETA was 1300.
Wx was excellent compared to the previous days, but sudden windshear can always happen. Very rare to cause such a loss of speed but not impossible.
Bird strike could be also a possibility, but very rare.
I have been told gear was downed quite late, this could explain a gliding approach, with a final decision to land on the soft wet grass. If this is confirmed they are heros for ever, and then it was possibly a bird strike over Hounslow, or fuel starvation.
We will soon find out. They are all alive
...fuel starvation is not impossible, due to faulty gauges of course!If it was wind shear instead, excellent handling on final. Soft landing on grass.
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I may be wrong....
Danny wrote:
"Whilst I have no experience of the B777, it certainly looks as though this a/c landed at very low speed and probably at stall speed. This, possibly due to the pilots trying to extend their glide to at least put it down within the perimeter of the airport."
I may well be wrong and please feel free to correct me, but how does landing at very low speed or at the stall speed increase the glide? I thought the maximum glide distance would be achieved at best glide speed which is presumably quite a lot greater than the stall speed on a 777? And therefore that any speed either greater or lesser would only have the effect of reducing the glide distance. I don't dispute that the crew would have wanted to slow the aircraft as much as possible just prior to touching down - but I would have thought that slowing to stall speed in order to try and make the perimeter would be an extraordinarily bad idea....
Please feel free to tell me I'm talking rubbish!
"Whilst I have no experience of the B777, it certainly looks as though this a/c landed at very low speed and probably at stall speed. This, possibly due to the pilots trying to extend their glide to at least put it down within the perimeter of the airport."
I may well be wrong and please feel free to correct me, but how does landing at very low speed or at the stall speed increase the glide? I thought the maximum glide distance would be achieved at best glide speed which is presumably quite a lot greater than the stall speed on a 777? And therefore that any speed either greater or lesser would only have the effect of reducing the glide distance. I don't dispute that the crew would have wanted to slow the aircraft as much as possible just prior to touching down - but I would have thought that slowing to stall speed in order to try and make the perimeter would be an extraordinarily bad idea....
Please feel free to tell me I'm talking rubbish!
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Who can we blame?
Speaking as an agnostic, I simply don't know! :-)
After the initial shock/horror probe instinct had left us and the happiness of the outcome had overcome me and my son we settled back to watch the telly coverage.
All day and evening the BBC has tried to find the sensational angle on this incident. And failed. Dismally.
TV Anchor: "How frightened were you?"
Passenger/Witness from a/c: "Pardon?"
TV Anchor: "Was it frightening?"
Passenger/Witness from a/c: "The landing felt a bit bumpy"
Kirsty Wark tried the same on Newsnight and made a complete front bottom of herself. The man from BALPA was painfully polite to the sad hack.
I'm just a pax, guys and gals, but I've loved planes since my boyhood as a cadet on AEFs in RAF Chipmunks out of Turnhouse Aerodrome.
Today has been a great day for anyone who loves flying, albeit for all of the wrong reasons.
P.S. Ian Shoesmith is only doing his job. And the people who are sitting on their hands ignoring him are doing their's also.
Peace to you all.
After the initial shock/horror probe instinct had left us and the happiness of the outcome had overcome me and my son we settled back to watch the telly coverage.
All day and evening the BBC has tried to find the sensational angle on this incident. And failed. Dismally.
TV Anchor: "How frightened were you?"
Passenger/Witness from a/c: "Pardon?"
TV Anchor: "Was it frightening?"
Passenger/Witness from a/c: "The landing felt a bit bumpy"
Kirsty Wark tried the same on Newsnight and made a complete front bottom of herself. The man from BALPA was painfully polite to the sad hack.
I'm just a pax, guys and gals, but I've loved planes since my boyhood as a cadet on AEFs in RAF Chipmunks out of Turnhouse Aerodrome.
Today has been a great day for anyone who loves flying, albeit for all of the wrong reasons.
P.S. Ian Shoesmith is only doing his job. And the people who are sitting on their hands ignoring him are doing their's also.
Peace to you all.
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"actually, scratch that. my favourite quote......"
My favourite of the day has to be:
"it appears that BA are trying to block the view, a large plane, I think it's a jumbo has been parked in the way"
Actually it wasn't a 747, it was an A319... New coverage for the first hour or so was truely terrible!
My favourite of the day has to be:
"it appears that BA are trying to block the view, a large plane, I think it's a jumbo has been parked in the way"
Actually it wasn't a 747, it was an A319... New coverage for the first hour or so was truely terrible!
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@ D O Guerrero
You are correct that best glide speed is not stall speed, and an indefinite glide is best achieved at best glide speed.
However, gliding involves exchanging potential energy for kinetic energy (or, using a gravity component along the flight path to combat drag). If you were trying to extend a glide, and were, say, 500ft AGL, at say 1.3vs, you might be better off trying to use up some of the stored KE represented by the speed rather than simply use up that 500ft. Exactly what the best energy management would be is dependent on a lot of aircraft dependent factors, but hitting the ground at your lowest possible flying speed does ensure there was no wasted energy left which might have been used to extend the glide.
You are correct that best glide speed is not stall speed, and an indefinite glide is best achieved at best glide speed.
However, gliding involves exchanging potential energy for kinetic energy (or, using a gravity component along the flight path to combat drag). If you were trying to extend a glide, and were, say, 500ft AGL, at say 1.3vs, you might be better off trying to use up some of the stored KE represented by the speed rather than simply use up that 500ft. Exactly what the best energy management would be is dependent on a lot of aircraft dependent factors, but hitting the ground at your lowest possible flying speed does ensure there was no wasted energy left which might have been used to extend the glide.
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We'll find out what happened soon enough - all the evidence, electronic, physical and human, is intact - and no doubt the right lessons will be learned. There's talk of the first official preliminary report coming out by the weekend, so whatever actually happened is no mystery to those on the ground (as it were), and that may be worth thinking about in its own right while we're waiting for yer actual facts. I'm hoping for heroes rather than villains.
Meanwhile, I think there's a good discussion to be had on PPrune and the press. I've got lots of ideas, as I'm sure have lots of others on all sides, but I don't know which forum is best for the kick-off. If TPTB would give a lead on that technicality, I'm happy to smear myself with antelope scent and leap into the lion's den...
R (a hack)
Meanwhile, I think there's a good discussion to be had on PPrune and the press. I've got lots of ideas, as I'm sure have lots of others on all sides, but I don't know which forum is best for the kick-off. If TPTB would give a lead on that technicality, I'm happy to smear myself with antelope scent and leap into the lion's den...
R (a hack)
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D O Guerrero:
Aircraft approach at a speed which gives them a margin above the stall speed (usually around 30% higher). In an emergency such as this, this 30% extra speed can be traded for height and therefore 'stretch' the flight path compared to that which would result from flying 30% above Vs with no power. It is a measure which has only a limited life, since once the stall speed is close the nose must be lowered again to prevent the stall. Then the aircraft is committed to where it will end up. It needs fine judgement and the failure to occur not before a certain point for it to work and the aircraft to reach the field. it would appear that in this case it worked, so well done to the teams aboard!
Unfortunately, there are too many crash sites in history where an attempt to 'stretch the glide' had insufficient energy (potential or kinetic) for it to work and the result was a wreck.
Aircraft approach at a speed which gives them a margin above the stall speed (usually around 30% higher). In an emergency such as this, this 30% extra speed can be traded for height and therefore 'stretch' the flight path compared to that which would result from flying 30% above Vs with no power. It is a measure which has only a limited life, since once the stall speed is close the nose must be lowered again to prevent the stall. Then the aircraft is committed to where it will end up. It needs fine judgement and the failure to occur not before a certain point for it to work and the aircraft to reach the field. it would appear that in this case it worked, so well done to the teams aboard!
Unfortunately, there are too many crash sites in history where an attempt to 'stretch the glide' had insufficient energy (potential or kinetic) for it to work and the result was a wreck.