BA038 (B777) Thread
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"BA038 - The Truth About Flight BA038"
Probably written by the same 10 year olds that still think the world is flat. What a complete load of baloney.
Probably written by the same 10 year olds that still think the world is flat. What a complete load of baloney.
Stercus Accidit
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It is still an Interim report and it states that ice PROBABLY contributed to the reduction in engine thrust. The AAIB is still not prepared to state definitively the cause of the accident.
I still suspect that it was a programming error in the engine management software. A combination of events during the descent, the hold and the final approach produced an event that did not figure in the long list of IF/THEN statements that control how the engines operate in any given scenario.
Flame me if you like but I maintain that, if it was ice, then the problem would have surfaced long before now.
I still suspect that it was a programming error in the engine management software. A combination of events during the descent, the hold and the final approach produced an event that did not figure in the long list of IF/THEN statements that control how the engines operate in any given scenario.
Flame me if you like but I maintain that, if it was ice, then the problem would have surfaced long before now.
Xeque:
Perhaps you can explain how an error in the software caused cavitation in the pumps?
Ah, I thought not.
I still suspect that it was a programming error in the engine management software
Ah, I thought not.
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Vindicated
if it was ice, then the problem would have surfaced long before now.
To all of us that said "fuel flow restriction caused by wax or ice crystals or both" lets pour ourselves a large Gin & Tonic. With ice, of course.
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I heard early on that they'd apparently had low fuel temp warning messages, but there was nothing to substantiate this.
BBC NEWS | England | London | 'Ice in fuel' caused BA jet crash
ECAM Actions.
BBC NEWS | England | London | 'Ice in fuel' caused BA jet crash
ECAM Actions.
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I haven't read the whole thread, so apologies if this has been asked before.
But re "BA038 - The Truth About Flight BA038" : WHY is it "baloney", please? I don't expect chapter and verse, just one or two pointers.
Not a wind-up, a straight question. I'm just an interested and reasonably well informed observer and I can't see anything in it which is obviously wrong or impossible.
But re "BA038 - The Truth About Flight BA038" : WHY is it "baloney", please? I don't expect chapter and verse, just one or two pointers.
Not a wind-up, a straight question. I'm just an interested and reasonably well informed observer and I can't see anything in it which is obviously wrong or impossible.
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Ice/ICE(EK) Baby
I think this investigation is in the hands of the very best professionals. If ice in the fuel resulting in pitting in fuel pumps is the interim conclusion of the cause, then I am sure that is with very good grounding.
There are, however, a few obvious questions:
1. Since the lifting of overflight rights by the Soviets, quite a few years ago, thousand if not millions of aircraft have flown from HKG and Chinese airports over Mongolia and Siberia to Europe with few, if any, similar problems. Also, in the event of fuel freezing, warnings would alert crew to reduce altitude and, whilst understanding that this would not necessarily apply if water was the cause,the problems occured just before landing and, therefore, having already more than adequately responded even should warnings have been made. And there is no suggestion that they were. Did BA038 make a very rapid descent so as not to allow unfreezing or were the pumps so badly pitted by that stage that the ice alone was no longer the problem? Is this, then, a problem unique to the specific design of the fuel pumps in the RR engines on the 777? Is this the reason why UK authorities are "Prodding" Boeing to investigate other engines also?
2. There are other reported incidents (MH ex PER etc.) of unusual 777 power responses to automated commands in conditions far less likely to involve freezing of/in fuel Whilst of course all incidents are entirely different, one wonders which engine types were involved in prior incidents and, if not, what if any other similarities might exist?
There are, however, a few obvious questions:
1. Since the lifting of overflight rights by the Soviets, quite a few years ago, thousand if not millions of aircraft have flown from HKG and Chinese airports over Mongolia and Siberia to Europe with few, if any, similar problems. Also, in the event of fuel freezing, warnings would alert crew to reduce altitude and, whilst understanding that this would not necessarily apply if water was the cause,the problems occured just before landing and, therefore, having already more than adequately responded even should warnings have been made. And there is no suggestion that they were. Did BA038 make a very rapid descent so as not to allow unfreezing or were the pumps so badly pitted by that stage that the ice alone was no longer the problem? Is this, then, a problem unique to the specific design of the fuel pumps in the RR engines on the 777? Is this the reason why UK authorities are "Prodding" Boeing to investigate other engines also?
2. There are other reported incidents (MH ex PER etc.) of unusual 777 power responses to automated commands in conditions far less likely to involve freezing of/in fuel Whilst of course all incidents are entirely different, one wonders which engine types were involved in prior incidents and, if not, what if any other similarities might exist?
Last edited by philipat; 4th Sep 2008 at 16:14. Reason: Typos
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Xeque
Read the report, it clearly explains that the engine control units did exactly what they are designed to do, correctly detecting and reacting to the events of the last 720ft of the descent.
It also clearly states that this incident is unique in 6.5 million flight hours, so your assertion that it would have surfaced before doesn't fit with the observed instances of the event.
Fascinating report, and clearly some more tests that exactly recreate a 777/Trent 800 installation will be needed to accurately pin down the details of what and why as the tests that have been done show some differences from the recorded parameters on BA038.
Read the report, it clearly explains that the engine control units did exactly what they are designed to do, correctly detecting and reacting to the events of the last 720ft of the descent.
It also clearly states that this incident is unique in 6.5 million flight hours, so your assertion that it would have surfaced before doesn't fit with the observed instances of the event.
Fascinating report, and clearly some more tests that exactly recreate a 777/Trent 800 installation will be needed to accurately pin down the details of what and why as the tests that have been done show some differences from the recorded parameters on BA038.
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In response to post #1713:
Apart from the fact that nearly all of it is factually incorrect, there is nothing wrong with "The Truth About BA038".
In response to post #1718:
Why the outbound flight?
ECAM Actions.
Apart from the fact that nearly all of it is factually incorrect, there is nothing wrong with "The Truth About BA038".
In response to post #1718:
Why the outbound flight?
ECAM Actions.
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As always a very informative and clear AAIB report. As they say themselves, many questions remain, I was thinking about the following items not mentioned in the report:
- what was the impact of the high air humidity during the approach? (intake through vents?)
- could the fuel temperature in some more exposed parts of the pipework (ex. the pylon) be considerably lower than the temp measured by the single main tank probe, where I assume the temps are influenced by the great mass of fuel, even in the coldest areas of the tank. Could this have caused icing or even waxing of the fuel in those cold spots downstream of the boost pumps?
- what was the impact of the high air humidity during the approach? (intake through vents?)
- could the fuel temperature in some more exposed parts of the pipework (ex. the pylon) be considerably lower than the temp measured by the single main tank probe, where I assume the temps are influenced by the great mass of fuel, even in the coldest areas of the tank. Could this have caused icing or even waxing of the fuel in those cold spots downstream of the boost pumps?
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Ba038 (b777)
the AIIB report states that military aircraft use a fuel additive that lowers the freezing point of water in the fuel.
Does anyone know why this is not used on civil aircraft.
Does anyone know why this is not used on civil aircraft.
I think the most interesting/important part of the report is this:
Which opens up the possibility that the BA38 scenario might not be confined to the RR 777, or indeed to the 777 at all...
However, it should be recognised that throughout the investigation all of the testing and research into the root cause of this accident has been conducted on the Boeing 777 / Trent 800 aircraft engine combination, and it is unknown whether other aircraft / engine combinations that have already been certificated might also be vulnerable to this previously unforeseen threat.
Therefore:
Safety Recommendation 2008-048
It is recommended that the Federal Aviation Administration and the European Aviation Safety Agency should take immediate action to consider the implications of the findings of this investigation on other certificated airframe / engine combinations.
Therefore:
Safety Recommendation 2008-048
It is recommended that the Federal Aviation Administration and the European Aviation Safety Agency should take immediate action to consider the implications of the findings of this investigation on other certificated airframe / engine combinations.
Aircraft Internal Piping Different With Different Engines?
Does anyone know if the aircraft internal fuel piping is different for each type of engine installed on the 777? This would have a bearing on whether the problem is unique to the 777/Trent combination.