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Old 9th Feb 2010, 18:10   #2881 (permalink)
 
Join Date: Oct 2009
Location: Durham
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PG...thanks for your opinion..but

That report will prolly be read by a wider audience than the official version and of course it is an interpretation. It has pics and good precis and is objective.

For people like me it is wunnerful because I can see the parts and understand what went on. It makes sense.

I don't think this will happen again due to the modifications made as result of this accident. That is all I seek. The outcome is postive and the world is safer..whatmore could anyone want?
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Old 9th Feb 2010, 18:15   #2882 (permalink)
 
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Quote:
Anyone baying for the CVR, forget it. The crew probably swore, said good-bye to their loved ones, before they knew they were going to make it. What do you expect?
Instead of swearing some crew communication could have helped to detect that the AP failed to be disconnected as it was believed.
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Old 9th Feb 2010, 18:15   #2883 (permalink)
 
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Quote:
I'd believe that an immediate retraction to Flaps 20 at Vref might be the best plan. Sadly, the AAIB report doesn't give the next guys any knowledge.
Aerodynamic basics would state that there is no set "rule" you can derive. The higher you are, the lower the optimum flap setting would be. As you get lower the lower stall speed with more flap outweighs the drag.

It is not the AAIB's job to (re)write handling manuals:
Quote:
The purpose of the AAIB is:

"To improve aviation safety by determining the causes of air accidents and serious incidents and making safety recommendations intended to prevent recurrence"
...It is not to apportion blame or liability.

Chief Inspector
They went as far in this report to analyse the FC actions as were relevant to the accident - in short, a no notice untrained for emergency, and their actions pretty much resulted in an optimal outcome:
Quote:
...they kept the aircraft flying and under control so that, at impact, it was wings level and at a moderate pitch attitude
Fundamentally this is a design/engineering accident, and little to learn from the FC pov - IMHO it is impractical to expect "drills" to be produced for every eventuality - especially since in this type of accident they would need to be "memory"...

Just my 2ps worth

NoD
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Old 9th Feb 2010, 18:28   #2884 (permalink)
 
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Quote:
IMHO it is impractical to expect "drills" to be produced for every eventuality
It's not a matter of different eventuality but basic fundamentals. Losses of thrust during initial climb requires to control:

- Safe flight path
- Optimum speed
- Configuration (drag)

There is basically no difference when this happen during an approach, there is no need for a "special" procedure. I regret that the AAIB didn't consider including few lines about it.
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Old 9th Feb 2010, 18:31   #2885 (permalink)
 
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Location: Penryn, Cornwall
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Quote:
Instead of swearing some crew communication could have helped to detect that the AP failed to be disconnected as it was believed.
which will, no doubt, bring down the wrath yet again of the god-like pilots on poor old sfly. But, people, she has a point. Throughout my reading of this thread I've been amazed by the pure coolness displayed by these guys in leaving the a/p engaged until it tripped at stick-shaker. What faith in automation!

and now it turns out the F/O "omitted" to disengage it. That doesn't sound like a deliberate (and oh so cool) action.

And surely you guys out there see the point. Might it have been better to hand-fly from the moment the problem was identified? Perhaps not. Certainly the outcome could hardly have been better. But I think we'd all like to know.
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Old 9th Feb 2010, 18:35   #2886 (permalink)
 
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Pettifogger -

The transcripts for USAIR 1549 are available. 3+28 (208 seconds) from impact to impact.

FO Skiles - Oh, sh*t
CA Sully - Oh, yeah

After that they were too busy to make any personal comments. Sully has said that his family never crossed his mind.

I would guess that the BA038 crew had the same focus.
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Old 9th Feb 2010, 18:41   #2887 (permalink)
 
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SFLY
95% of pilots will follow the flight director if flying manually. The flight director will be trying to keep the aircraft on the ILS, exactly what the AP was tryting to do. So why increase the workload, when trying to faultfind an emergency for which there is no drill. For the 15-20 seconds that elapsed between when the FO intended to take out the AP, and when he did, the difference in flight path is hardly worth talkingabout, if you want something pointless to contemplate, why not have a heated debate about whether they should have asked all the passengers to move to the back of the aircraft, in an attempt to reduce control drag!

Last edited by xavier95; 9th Feb 2010 at 23:15.
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Old 9th Feb 2010, 18:59   #2888 (permalink)
 
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Pettifogger ;

" .........the AAIB's report to be well researched, well written and comprehensive in scope. I believe that they have reached the right conclusions and have provided sufficient analysis to justify those conclusions. ......."

The report is hardly "comprehensive in scope" as it does not even begin to try to cover representative tests of the presumed actual fuel/water mixture in the plane at the time of the accident.

Likewise their "analysis" is non-existent as they totally dodge this issue.

The report screams out both a lack of rigourous testing and avoidance of the huge cost that would be involved in both undertaking such research and then applying it to ALL airframe and engine combinations.

Releasing a report with such glaring gaps is plain weird.
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Old 9th Feb 2010, 19:02   #2889 (permalink)
 
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Quote:
Vref 135 from the 777 performance pages is for a 440,000 lbs a/c(I don't recall BA 038's weight).
410,880 lbs

SoS
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Old 9th Feb 2010, 19:06   #2890 (permalink)
 
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This is the longest, and most comprehensive, AAIB report I can recall. I guess as a taxpayer I ought to be glad that the AAIB does not have to pander to idiots who want the report to explain the movements of every component throughout their entire life, the movement of the planets and the variations in the planetary magnetic fields.
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Old 9th Feb 2010, 19:08   #2891 (permalink)
 
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Phil Gollin

While the actions of the crew in the last, doubtless frenetic, seconds of the flight are both interesting and admirable - so far as I am concerned - I have to say I share Phil Gollin's concerns that 'eyes have been taken off the ball.' His well researched and knowledgable post should really have put questions of flaps raised or not, to one side. The reason those two gentlemen, plus all their crew and passengers were in that terrifying situation is because two of the most beautifully engineered machines for producing thrust, didn't. Both at the same time, give or take a few seconds.

I joined this forum because the circumstances of BA038 were, to this uninvolved bystander engineer, quite simply; staggering. Unbelievable. And yet today the report uses the word 'probably'. Entrained ice in the fuel probably caused the engines to 'choke' simultaneously. However, unless I've missed some big numbers somewhere, it seems quite extraodinary that so little water could choke such big engines at such a critical moment in the flight.

It appears to my untrained eye that the engines were consuming fuel at varying rates - in the last twenty odd seconds - but between one and two kilograms per second. Phil Gollin's text stated that it was estimated that there was a total of 5.14 Lt of water in all the fuel in the aeroplane at take off and sucked in during the flight. It just seems too little, because if all the water in the tanks suddenly arrived at the delivery system in the last few seconds, it would still only represent about 10% of the fuel being consumed at the time.

Since entrained water and ice in fuel systems has been endemic all through the history of high altitude, high speed flight and certainly during the whole operating career of the 777 - a lovely aeroplane to my mind - why hasn't it happend before?

Perhaps it has been decided to apply the principle of Occam's Razor and accept that ice is 'probably' the cause. Although I apply the principle myself in my own job often enough, the pricking of my engineer's thumbs suggests to me that something, somewhere has been forgotten.

Roger.
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Old 9th Feb 2010, 20:43   #2892 (permalink)
 
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Mmmayday38:
for some it is still not possible to accept that gut feeling flying may actually produce best possible results.
I still believe that your post BA038 (B777) Thread is a glamorous example of humble and professional human side of flying.

thank you!

long time ago J.Conrad wrote a book on sailors - 'Lord Jim' - from which i have learned one thing: one can not tell how he would have behaved in given situation until he would have lived through such experience himself.

hopefully the Report's recommendations might help in preventing it happening ever again...
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Old 9th Feb 2010, 20:48   #2893 (permalink)
 
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Quote:
Burger Thing -
on a MD-11 for example, if you are on a 2 Engine approach and loose a second engine on short final, one of the Memory Items is to raise the flaps from 35 to 28.
That could very well be. BUT.....you still have an engine left for some thrust. BA038 had NOTHING.
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Old 9th Feb 2010, 21:31   #2894 (permalink)
 
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Well done Peter and John in doing your best in such limited time. I cannot imagine being in the same position.

Additionally a fantastic job by ATC in response. Just heard the audio on BBC. Chilling stuff but well handled.

Stop criticising and let's move on.
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Old 9th Feb 2010, 22:12   #2895 (permalink)
 
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Landroger

I recall that, from much earlier in the investigation, data on 777 engine and aircraft handling was checked for many hundreds of thousands of flights (or was that flight hours? Not sure) and the parameters found for BA038 and G-YMMM's last journey were right down at the very tail of the distribution with the lowest rates of climb and hence the lowest incremental thrust/fuel flow, coupled with a very long flight at unusually cold OAT followed by an unusual uninterrupted continuous descent into LHR with only one power application above idle which rapidly resulted in the thrust reduction seen.

While I can see Phil Gollin's point about things that have been left out of the report, it is clear that such a weight of unusualness is bound to have effects that may never have been seen before.

I also think that the volume of "ice" - by which I mean some sort of semi-frozen ice/water/fuel mixture may well exceed that theorized by a simple consideration of the effect of freezing those 5.14 litres of water, but even then the crucial pipes are quite short so a little "ice" clearly didn't need to go such a long way.

But, clearly more to be learned.

The question is, can anyone be expected to have the strength of character required to investigate further and then, if the facts show it to be necessary, convince the industry to spend what could be a very large quantity of money to correct the behaviour of every fuel system on the planet?

Last edited by Feathers McGraw; 9th Feb 2010 at 22:13. Reason: Formatting!
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Old 9th Feb 2010, 22:42   #2896 (permalink)
 
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Occam's razor (or Ockham's razor[1]), entia non sunt multiplicanda praeter necessitatem, is the principle that "entities must not be multiplied beyond necessity" and the conclusion thereof, that the simplest explanation or strategy tends to be the best one. The principle is attributed to 14th-century English logician, theologian and Franciscan friar, William of Ockham. Occam's razor may be alternatively phrased as pluralitas non est ponenda sine necessitate ("plurality should not be posited without necessity")[2]. The principle is often expressed in Latin as the lex parsimoniae (translating to the law of parsimony, law of economy or law of succinctness). When competing hypotheses are equal in other respects, the principle recommends selection of the hypothesis that introduces the fewest assumptions and postulates the fewest entities while still sufficiently answering the question. It is in this sense that Occam's razor is usually understood. To quote Isaac Newton, "We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Therefore, to the same natural effects we must, so far as possible, assign the same causes."[3

More on Wiki ( from which this intro is lifted) for anyone interested.

In the modern idiom, keep it simple, stupid.
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Old 9th Feb 2010, 22:56   #2897 (permalink)
 
Join Date: Jan 2008
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Quote:
misd-agin
Pettifogger -

The transcripts for USAIR 1549 are available. 3+28 (208 seconds) from impact to impact.

FO Skiles - Oh, sh*t
CA Sully - Oh, yeah

After that they were too busy to make any personal comments. Sully has said that his family never crossed his mind.

I would guess that the BA038 crew had the same focus.
No doubt. But when sliding along on the grass? Have a look at this at 2.08 to 2.16
BBC News - BA crash captain: 'I thought it was my time to die'
This clip also contains Capt. P Burkhill's recollection of his flap/drag decision and observed consequences.
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Old 9th Feb 2010, 23:04   #2898 (permalink)
 
Join Date: May 2002
Location: Green and pleasant land
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As a humble SLF and one-time glider pilot,

Having read this thread and various offshoots, and having just listened to the ATC recording, which highlighted how incredibly calm and measured the responses were from each of the people/groups involved, may I just say how much I was impressed by the actions of all those involved in this incident. Truly professional !!

There are those who post here who will always try to seek blame and unfairly denigrate individuals, regardless of the facts. To them I would say **** ***

CS
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Old 9th Feb 2010, 23:46   #2899 (permalink)
 
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phil gollin

Quote:
The report is hardly "comprehensive in scope" as it does not even begin to try to cover representative tests of the presumed actual fuel/water mixture in the plane at the time of the accident.

Likewise their "analysis" is non-existent as they totally dodge this issue.

The report screams out both a lack of rigourous testing and avoidance of the huge cost that would be involved in both undertaking such research and then applying it to ALL airframe and engine combinations.

Releasing a report with such glaring gaps is plain weird.
P
Your last statement desrves a rebuttal

It's not the job of the investigating agency to research and develop all possible contributors in future accidents. It is generally considered that an investigation report has done a fair job if its recommendations are timely and sound enough to make it unlikley that the accident will be repeated before the designer-regulator has addressed the issues.

Sometimes it's important to be aware of the fine line between design intent, regulation and after-the-fact discovery. Lessons Learned
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Old 9th Feb 2010, 23:49   #2900 (permalink)
 
Join Date: Feb 2009
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Feathers McGraw

Quote:
I recall that, from much earlier in the investigation, data on 777 engine and aircraft handling was checked for many hundreds of thousands of flights (or was that flight hours? Not sure) and the parameters found for BA038 and G-YMMM's last journey were right down at the very tail of the distribution with the lowest rates of climb and hence the lowest incremental thrust/fuel flow, coupled with a very long flight at unusually cold OAT followed by an unusual uninterrupted continuous descent into LHR with only one power application above idle which rapidly resulted in the thrust reduction seen.
I accept that BA038's flight profile might have been unusual, or rather an unusual concatenation of ordinary events, the chance pattern of which placed them at an extreme point on the 'bell curve'. But even the extreme position on the curve does not preclude the possibilty of bilateral 'engine failure' if say, just one extraordinary item was removed and thus something like this ought to have happened before?

I don't know just how sophisticated any tests have been, but it is not beyond the wit of man and an imaginative test rig, to reproduce the accident conditions routinely. Some aircraft components - although not a whole engine I wouldn't have thought - a quantity of appropriate fuel and reliable means of lowering the temperature of tanks, pumps, pipes and control systems. Unless and until someone has done this and reproduced the fault - where reproduce is the scientific key - it will not be possible to say we have the answer to BA038.

I think Phil Gollin has said as much, but with greater scientific weight than I could possibly aspire to. It seems that the fault condition could be achieved - intermittently - but only by forcing certain parameters well outside those thought to obtain in G-YMMM. One of which was to artificially increase the proportion of water by direct injection near to suspected critical components. (Italics my speculation.)

If this localised increase in water density was the only way to trigger the fault condition, then the fact that - according to Phil Gollin's text - ice tends to form on the bottom - coldest - part of the tank (and was extremely difficult to dislodge) suggests that this would keep the bulk of the available water away from anything vital. And even if it did in one tank, enough to choke its engine, why did it happen in the other at the exactly the same time?

All I say is, again in my opinion, that this accident was extraordinary from the start, but after all this time the answer appears to put it in the category of 'the perfect crime' and only just short of it being caused by an Alien Energy Beam.

Roger.
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