BA038 (B777) Thread
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suninmyeyes - you've just written my retort for the next wanton comment I get...which may well be tomorrow night at work
Good stuff
Sorry I can't afford the ghost writing fees.
In the meantime, can those who don't have a clue just be thankful Messrs Burkhill and Coward did.
Good stuff
Sorry I can't afford the ghost writing fees.
In the meantime, can those who don't have a clue just be thankful Messrs Burkhill and Coward did.
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Fuel temperature variations
Is it a fact that the port wing probe is at the coldest point in the fuel's route from tank to engine?
If the pipework - for example in the pylons - could be colder, then any tests based on bulk fuel temperature would be optimistic.
If the pipework - for example in the pylons - could be colder, then any tests based on bulk fuel temperature would be optimistic.
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no water checks carried out
bae146 is clearly stating that at british airways the water sump checks were never carried out, just stamped as being done. I recall earlier in this post baengineering saying the same thing! Clearly water was building up in this centre tank from poor maintenance practice that was widespread at cc.
All i can say is the sooner the media gets this out to the wider public the better. Also why has ba lied in the report? Making out they were doing a study on water sumping just before the incident! It would be amusing if the gravity of the situation were not so significant. A large aircraft nearly down over london.
Any other ba engineers wish to comment?
All i can say is the sooner the media gets this out to the wider public the better. Also why has ba lied in the report? Making out they were doing a study on water sumping just before the incident! It would be amusing if the gravity of the situation were not so significant. A large aircraft nearly down over london.
Any other ba engineers wish to comment?
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Originally Posted by rainboe
I flew 747s for 18 years- you would not get me throwing the nose down at all!
Originally Posted by AAIB
The stick shaker activated at approximately 170 ft, and shortly afterwards the First Officer made a nose down pitch control input which reduced the aircraft pitch attitude and caused the auto pilot to disconnect.
To dxzh:
Thank you for your gentleman's post. I really appreciated your comments and your open minded point of view. I'm sorry not to elaborate more on it as it is bedtime but you made your way to convince me.
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Well said Rainboe! Similar to you, I have some 23 years' experience on wide-bodies and nearly 30 years on four-engine jet transports and I can see a massive contrast between the opinions from the informed professionals and that of some of the inexperienced wannabees. I have been lurking for most of this thread, just amazed at some of the uninformed rubbish that has been posted - suninmyeyes, you are spot on with your recent post.
dxzh has some very sensible and constructive ideas to put forward - especially the recent response to sispanys ria, which was excellent reading - and suninmyeyes' subsequent comment says it just the way it is.
On the subject of the recent AAIB Interim Report, I congratulate them on a detailed and comprehensive update on the progress of the investigation. I, for one, have total confidence in their competence as an investigative body.
Now, back to lurking on this thread ...
JD
dxzh has some very sensible and constructive ideas to put forward - especially the recent response to sispanys ria, which was excellent reading - and suninmyeyes' subsequent comment says it just the way it is.
On the subject of the recent AAIB Interim Report, I congratulate them on a detailed and comprehensive update on the progress of the investigation. I, for one, have total confidence in their competence as an investigative body.
Now, back to lurking on this thread ...
JD
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Misinformation
BlueRay:
This misinformation is based on earlier misinformation and provides a good example of why many professionals will no longer contribute.
Firstly, the posts you are referencing did not refer to specific procedures which had been signed-off without implementation. Secondly, they were clearly from someone with an axe to grind, probably a disaffected (Ex?) employee.
I suggest that before you start reaching such conclusions you read the entire thread. This would give a much broader understanding and would allow you to judge the quality and credibility of individual posts within the bigger picture.
bae146 is clearly stating that at british airways the water sump checks were never carried out, just stamped as being done. I recall earlier in this post baengineering saying the same thing! Clearly water was building up in this centre tank from poor maintenance practice that was widespread at cc.
All I can say is the sooner the media gets this out to the wider public the better. Also why has ba lied in the report? Making out they were doing a study on water sumping just before the incident! It would be amusing if the gravity of the situation were not so significant. A large aircraft nearly down over london.
All I can say is the sooner the media gets this out to the wider public the better. Also why has ba lied in the report? Making out they were doing a study on water sumping just before the incident! It would be amusing if the gravity of the situation were not so significant. A large aircraft nearly down over london.
Firstly, the posts you are referencing did not refer to specific procedures which had been signed-off without implementation. Secondly, they were clearly from someone with an axe to grind, probably a disaffected (Ex?) employee.
I suggest that before you start reaching such conclusions you read the entire thread. This would give a much broader understanding and would allow you to judge the quality and credibility of individual posts within the bigger picture.
Last edited by philipat; 10th Sep 2008 at 01:34. Reason: Typos
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Originally Posted by Rainboe
These big jets are not like gliders with instant flap in 1/2 second. The only answer in a giant jet is to hold attitude and desperately hope you will retain enough elevator control authority to stop the nose eventually dropping as the speed falls and you lose your elevators
I'm sure you are experienced enough to understand that letting the AP following the GS is exactly the contrary of what you recommend: the AP didnt' hold the attitude but increased it up to 14 degrees nose up.
Originally Posted by Rainboe
instant flaps- they could take 20 seconds whilst sucking your elevator control dry of all power!
Originally Posted by Rainboe
That is why I am brutal with this bitching by sispanys ria. He thinks he is an expert because he taught engine out in a little single engine fighter with no control problems.
Originally Posted by Rainboe
Stick the nose down, and it may be the last thing you ever do.
Basically they did all the contrary of what you recommend (as an experienced heavy jet professional) :
They didn't hold the attitude
They did retract the flaps
They made a nose down input at low speed/altitude
As dxzh said very nicely, it's too bad that the newspaper needs to decide wether the crew made it right or wrong. In most cases, the truth is in between and we (as experienced professional) should be able to understand it clearly. It is absolutely not a matter of judging the crew, since they obviously are not the cause of the accident. Still, their actions could be analyzed for the sake of safety in finding how their actions could have been improved. According to Rainboe's attitude, I guess there wasn't so much of CRM during his 18 years of heavy 747 operations...
Last edited by sispanys ria; 10th Sep 2008 at 05:08.
Psychophysiological entity
There has to be some definition of 'pushing' or letting the nose down. It just can't have been a very pronounced maneuver.
Any attempt to sustain 14 degrees up as the speed came back towards the shake would be catastrophic, obviously. Somehow, that had to be corrected, and one would hope by just allowing the nose to come down a bit...accepting going below the glide, and trying to nail an attitude that was a last-ditch compromise.
I'll leave the flap setting out of the equation, as it may or may not have been just being part of that compromise.
Any attempt to sustain 14 degrees up as the speed came back towards the shake would be catastrophic, obviously. Somehow, that had to be corrected, and one would hope by just allowing the nose to come down a bit...accepting going below the glide, and trying to nail an attitude that was a last-ditch compromise.
I'll leave the flap setting out of the equation, as it may or may not have been just being part of that compromise.
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Suninmyeyes I completely agree with your sentiments as expressed in para 2, however and very sadly there will always be professionals and professionals, so its not always that easy to leave it to the professionals....
On another note a quick question. Does the 777 fuel tank contain sensors for ice as well as water?
On another note a quick question. Does the 777 fuel tank contain sensors for ice as well as water?
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Does the 777 fuel tank contain sensors for ice as well as water?
Originally Posted by Rainboe
instant flaps- they could take 20 seconds whilst sucking your elevator control dry of all power!
instant flaps- they could take 20 seconds whilst sucking your elevator control dry of all power!
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I would dearly love this sniping between factions to stop! I said eons ago on this thread that I do not know what I would have done in that situation.
As I said before, given a significant loss of available energy on the approach (as any pilot, powered or glider should know) there is an altitude above which it is beneficial to reduce flap and/or lower the nose to maintain best glide performance. There is an altitude below which is is beneficial to use the remaining energy to 'stretch' the glide. They, deliberately or inadvertently, chose the second. I suspect that at the moment of stick shake and a/p disconnect at 170' there was an awkward feeling that the choice may not have been right. All said and done, no-one died and the aircraft crashed on the airfield.
However, we cannot judge with the information we have available. I sincerely hope that some sort of 'official' analysis is produced somewhere of the 'best' solution so that it can be added to that mysterious store of 'background' knowledge all pilots have. Until then, rantings about stuffing the nose down, hydraulics being sucked dry are pointless.
As I said before, given a significant loss of available energy on the approach (as any pilot, powered or glider should know) there is an altitude above which it is beneficial to reduce flap and/or lower the nose to maintain best glide performance. There is an altitude below which is is beneficial to use the remaining energy to 'stretch' the glide. They, deliberately or inadvertently, chose the second. I suspect that at the moment of stick shake and a/p disconnect at 170' there was an awkward feeling that the choice may not have been right. All said and done, no-one died and the aircraft crashed on the airfield.
However, we cannot judge with the information we have available. I sincerely hope that some sort of 'official' analysis is produced somewhere of the 'best' solution so that it can be added to that mysterious store of 'background' knowledge all pilots have. Until then, rantings about stuffing the nose down, hydraulics being sucked dry are pointless.
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For all the bitching about the "attitude" / "GS" / "Speed".
Firstly, by leaving the AP in, you had 2(3) crew to discuss/action the best options in resolving the real problem, which lay in the engines...
For those of you who advocate lowering the nose to maintain the approach speed (~140K) the aircraft would have ended up well short* - unless you can also show us the profile as to when to now raise the nose / sacrifice airspeed.
The Flaps were retracted ~240' (IIRC) from 30 to 25. The 30 setting is almost all drag. I suspect this was inspired - the rate of loss of IAS would have been higher with Flap 30, so the stall / stick shake / end point would again have been earlier*.
I guess that with idling engines, a suitably trained and pre-notifed crew, it could be shown to have got to the threshold before landing. Lower nose, Flaps 25 (maybe 20?), even some ground effect - but it is barking mad to even suggest this crew should have tried it Contrary to the emergency handling procedures we are all taught, and irrelevant as a "lesson" because next time it occurs 1NM further out on the approach all would change and it would not make the threshold*
The actions by this crew just got the aircraft over the A30 and onto wet / soft ground, and "landed" with a tolerable RoD that saved everybody.
*Now just go and look at the A30, traffic, and the trees along the SE side. If the aircraft had come down before there, or even "over" the road / trees at very low altitude, the results would likely have been catastrophic...
NoD
PS suggest we do not even discuss the Sim here - I really cannot believe it is accurately modelled for engines out / ground effect etc.
Firstly, by leaving the AP in, you had 2(3) crew to discuss/action the best options in resolving the real problem, which lay in the engines...
For those of you who advocate lowering the nose to maintain the approach speed (~140K) the aircraft would have ended up well short* - unless you can also show us the profile as to when to now raise the nose / sacrifice airspeed.
The Flaps were retracted ~240' (IIRC) from 30 to 25. The 30 setting is almost all drag. I suspect this was inspired - the rate of loss of IAS would have been higher with Flap 30, so the stall / stick shake / end point would again have been earlier*.
I guess that with idling engines, a suitably trained and pre-notifed crew, it could be shown to have got to the threshold before landing. Lower nose, Flaps 25 (maybe 20?), even some ground effect - but it is barking mad to even suggest this crew should have tried it Contrary to the emergency handling procedures we are all taught, and irrelevant as a "lesson" because next time it occurs 1NM further out on the approach all would change and it would not make the threshold*
The actions by this crew just got the aircraft over the A30 and onto wet / soft ground, and "landed" with a tolerable RoD that saved everybody.
*Now just go and look at the A30, traffic, and the trees along the SE side. If the aircraft had come down before there, or even "over" the road / trees at very low altitude, the results would likely have been catastrophic...
NoD
PS suggest we do not even discuss the Sim here - I really cannot believe it is accurately modelled for engines out / ground effect etc.
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Swedish Steve thanks for the reply - the point I'm trying to clarify in my head is that will the sensor react differently to water than ice . It has been discussed quite openly that the water was a contributing factor after it had melted from ice, my point being that it appears that excessesive water in the tanks can be detected as a cause for concern but not neccesarily ice....
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I tried to estimate the obstacle clearance of BA038's flight path by comparing the FDR trace and Google Earth. It appears to have crossed A30 about 5 sec before touchdown at about 100 ft height. At that point there is a low (15-20 ft?) building 50 metres from the runway centerline as well as streetlight poles.
The next significant obstacle is a group of houses 700 metres from the touchdown point, where the plane was 14 sec from touchdown at 230 ft, nose high just before the stick shaker activated.
With full respect for the crew's action in a situation they had obviously never been trained for:
The hypothetical question is, would a slightly lower faster approach, reducing the margin to the houses, have left the plane with enough additional energy to flare over the road and (presumably) come down softer than the actual 1400 fpm vertical speed?
A second question. What if the airplane would have "sounded the alarm" at the earliest possible time, which according to the trace was about 54 sec before touchdown for the right engine and 45 sec for the left, as the EEC entered "Control Loop 17"? An immediate flap retraction to 20 degrees at that early point in time might actually have given some real benefit of reduced drag, even considering the ~10 sec retraction time. But how much?
The next significant obstacle is a group of houses 700 metres from the touchdown point, where the plane was 14 sec from touchdown at 230 ft, nose high just before the stick shaker activated.
With full respect for the crew's action in a situation they had obviously never been trained for:
The hypothetical question is, would a slightly lower faster approach, reducing the margin to the houses, have left the plane with enough additional energy to flare over the road and (presumably) come down softer than the actual 1400 fpm vertical speed?
A second question. What if the airplane would have "sounded the alarm" at the earliest possible time, which according to the trace was about 54 sec before touchdown for the right engine and 45 sec for the left, as the EEC entered "Control Loop 17"? An immediate flap retraction to 20 degrees at that early point in time might actually have given some real benefit of reduced drag, even considering the ~10 sec retraction time. But how much?
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The hypothetical question is, would a slightly lower faster approach, reducing the margin to the houses, have left the plae with enough additional energy to flare over the road and (presumably) come down softer than the actual 1400 fpm vertical speed?
A second question. What if the airplane would have "sounded the alarm" at the earliest possible time, which according to the trace was about 54 sec before touchdown for the right engine and 45 sec for the left, as the EEC entered "Control Loop 17"? An immediate flap retraction to 20 degrees at that early point in time might actually have given some real benefit of reduced drag, even considering the ~10 sec retraction time. But how much?
Take a clue from the AAIB - do they seem the slightest bit interested, at this stage, in the crew actions, or why the engines stopped
And are you seriously suggesting that as a result of this accident, we should look at training crews in unanticipated double engines failures on Final Approach, or might it be better to stop the engines failing in the first place
NoD