Article: NTSB: Emirates 777 continued flight after loud bang, messages
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It seems to me that some incredibly clever men - the engineers and designers at Boeing and Rolls Royce - put an incredibly large number of hours into coming up with a system that would give crews fair warning of a technical situation requiring crew action. Those same smart people, with a commercial product to sell to airlines - airlines with a primary mission of getting passengers to their destinations safely and if possible, without UNNECESSARY delay, came up with a system that advised crews of any degradation to their aircraft's (usually triply redundant) systems that did NOT require crew action.
During my training on the 777, it was stressed that we should not try to outguess the systems - and definitely not act upon any status message. Status messages are just that, STATUS messages, which, translated for those who need translation, means "a syatem (or systems) is (or are) not operating at 100%, but we, the men who designed this aircraft, after many hours of careful consideration and with many, many hours of deliberation - and much, much more information than you, the operating crew (and the Monday morning quarterbacks) can ever hope to have available to you - have come to the conclusion that those systems haven't degraded to the point where crew action is necessary".
If a crew found themselves departing their home port bound for an outport that provided less technical support or spares than the home port did, (or if the problem seemed to indicate that the aircraft might be AOG for as considerable time), it would be entirely reasonable, if, after consultation with maintenance and operations, the crew elected to return to base. In such circumstances, that decision would be primarily commercial, and I can see no problem with that.
Like 99% of others who've posted here, I don't have all the information on this incident, but from the limited information I've seen here, and with 12 years as a captain on the 777 behind me, I can't see that the crew did anything wrong.
During my training on the 777, it was stressed that we should not try to outguess the systems - and definitely not act upon any status message. Status messages are just that, STATUS messages, which, translated for those who need translation, means "a syatem (or systems) is (or are) not operating at 100%, but we, the men who designed this aircraft, after many hours of careful consideration and with many, many hours of deliberation - and much, much more information than you, the operating crew (and the Monday morning quarterbacks) can ever hope to have available to you - have come to the conclusion that those systems haven't degraded to the point where crew action is necessary".
If a crew found themselves departing their home port bound for an outport that provided less technical support or spares than the home port did, (or if the problem seemed to indicate that the aircraft might be AOG for as considerable time), it would be entirely reasonable, if, after consultation with maintenance and operations, the crew elected to return to base. In such circumstances, that decision would be primarily commercial, and I can see no problem with that.
Like 99% of others who've posted here, I don't have all the information on this incident, but from the limited information I've seen here, and with 12 years as a captain on the 777 behind me, I can't see that the crew did anything wrong.
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Like 99% of others who've posted here, I don't have all the information on this incident, but from the limited information I've seen here, and with 12 years as a captain on the 777 behind me, I can't see that the crew did anything wrong.
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sAx_R54
Personally, I’ve had a single medical assessment that was interpreted differently by two aviation doctors leading to two diverse assessments. I suppose if more doctors were brought in, there would be even more opinions leading to different outcomes. How can one set of ‘numbers’ lead to different interpretations in an applied science?
In the spirit of education (mine!) as a young pilot I would present various scenarios to the Captain . Invariably, the answer would be “well, that depends ….” What followed was a long discussion on what would encourage the best outcome for my contrived scenario.
Every pilot will accumulate as much information as possible before deciding on a course of action. Unfortunately, most decisions have to be made despite the lack of the information available to those reading about it! The course of action becomes a continuing re-assessment depending on the information as it becomes available. What you’re reading in these threads are the assessments of each individual based on their own experience as bits of information become known.
Personally, I’ve had a single medical assessment that was interpreted differently by two aviation doctors leading to two diverse assessments. I suppose if more doctors were brought in, there would be even more opinions leading to different outcomes. How can one set of ‘numbers’ lead to different interpretations in an applied science?
In the spirit of education (mine!) as a young pilot I would present various scenarios to the Captain . Invariably, the answer would be “well, that depends ….” What followed was a long discussion on what would encourage the best outcome for my contrived scenario.
Every pilot will accumulate as much information as possible before deciding on a course of action. Unfortunately, most decisions have to be made despite the lack of the information available to those reading about it! The course of action becomes a continuing re-assessment depending on the information as it becomes available. What you’re reading in these threads are the assessments of each individual based on their own experience as bits of information become known.
I believe that it was a piece of the inner honeycomb structure in the tail cone of the engine that departed the engine, and caused some minor damage to the thrust reversing system.
As has been pointed out by a number of posters in this thread, the status messages were just that - status messages - not warnings or instructions to land the plane immediately, and the crew acted accordingly. Also, MCC were well aware of the situation and monitored the aircraft the whole time to a safe landing.
No-one was in any immediate danger, and the crew, together with MCC did a superb job in handling this minor incident in a professional manner.
Enough said..!
As has been pointed out by a number of posters in this thread, the status messages were just that - status messages - not warnings or instructions to land the plane immediately, and the crew acted accordingly. Also, MCC were well aware of the situation and monitored the aircraft the whole time to a safe landing.
No-one was in any immediate danger, and the crew, together with MCC did a superb job in handling this minor incident in a professional manner.
Enough said..!
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I agree with wizofoz - and I wouldn't be surprised if MCC and the crew had a fair idea of what sort of failure had produced the symtoms.
Off topic slightly (and no implyed criticism); when I used to fly this route there actually weren't many airports between Moscow and Tbilisi that weren't NOTAMed unsuitable for various vague reasons. In fact sometimes the dispatcher issued an ETOPs OFP. Has this changed?
Off topic slightly (and no implyed criticism); when I used to fly this route there actually weren't many airports between Moscow and Tbilisi that weren't NOTAMed unsuitable for various vague reasons. In fact sometimes the dispatcher issued an ETOPs OFP. Has this changed?
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@CanadaKid @Desert Dawg Your final points are well founded. So this tale at least has demonstrated that the end does justify the means, as no harm resulted and all was well.
Therefore considering the points made in the #1 post, the material facts (hopefully not from the NoTW), suggest these in conclusion:
So had these items been MEL, I wonder how many would be happy to set take-off thrust and race towards the horizon of V1, safeguard in the knowledge that advisory only annunciations would continue after they had climbed above 400ft!
Inspiring safety?? Maybe!!
Thanks to all for your considered comments.
Therefore considering the points made in the #1 post, the material facts (hopefully not from the NoTW), suggest these in conclusion:
....Inspection of the aircraft in Dubai revealed "a large section" of the right engine's inboard fan duct and thrust reverser were missing, starting at the trailing edge and ripping forward.
Overall, officials estimated that 2.8-3.7m2 (30-40m2) section of engine covering to be missing, along with the primary exhaust nozzle outer skin. The primary nozzle inner skin had been "holed in several locations at the 12 to 1 o'clock position," the report stated.
External to the engine, the one tyre on the main landing gear "was observed to have a large cut to the sideway" of approximately 36cm (14in), officials said.
Overall, officials estimated that 2.8-3.7m2 (30-40m2) section of engine covering to be missing, along with the primary exhaust nozzle outer skin. The primary nozzle inner skin had been "holed in several locations at the 12 to 1 o'clock position," the report stated.
External to the engine, the one tyre on the main landing gear "was observed to have a large cut to the sideway" of approximately 36cm (14in), officials said.
Inspiring safety?? Maybe!!
Thanks to all for your considered comments.
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The risk was assessed by the crew on the day using information from various inputs and a decision was made.
Other (very delicate) question that comes into mind is does EK put any whatsoever pressure on their crews to bring an aircraft back into base? Having worked for various US and UK companies I have always felt a certain vibe from engineering to bring the plane back to base...
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I agree with wizofoz - and I wouldn't be surprised if MCC and the crew had a fair idea of what sort of failure had produced the symtoms.
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MCC monitoring real time
Anybody who fully trust MCC's analyses of the real time readings from their onboard maintenace computer probably live in an unreal world!
Read this from another thread :
Having said that there was no reason compelling reason for the crew to make an ATB to SVO. However I am confident the crew would have consulted MCC and Dispatch for all the relevant information and would have in their heads plans B, C and D in case something really went wrong. Multiple status messages are real cause for concern but no need for immediate crew action. However the crew had better brush up on their systems information/knowledge to be prepared to deal with highly possible inflight failures associated with those status messages. To just pay little attention them just because no pilot actions were required for status messages would be plain foolish.
Read this from another thread :
A few years ago, a colleague of mine had a small fuel leak ( which went undetected by even the sophiscated, high tech real time maintenance monitoring ) decided to go against the company's decision to continue to destination as their maintenance control reckoned the skipper was wrong in assessing a small anomaly as a fuel leak. When he insisted on diverting, they demanded he returned to base. However with the prevailing tailwinds, a 180 degrees return to base entails a 7 hour diversion whereas an enroute diversion would have been only a 2.5 hours; seeing the stupidity of the operations control/maintenance control, he countermanded the company's decision, wrested a grudging approval to divert to a suitable enroute airport where he was proven right that there was indeed an engine fuel leak. Technically, operationally and safety wise, he was vindicated. But the company put him through hell, grounded him for several weeks, trying every trick in the book to trip him during the various enquiries. He maintained technical and professional integrity throughout; he was finally released back on line with " no comment " on the incident. When he enquired further, he was quietly pulled aside and told that in the interest of his future contract ( it was a commuting contract ), he should " let go ". Of course he took the advice under protest. This was taken unkindly and true enough some time later he found himself " failed " a sim check under dubious circumstances. THE MESSAGE WAS CLEAR.
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They heard a loud bang "during takeoff". Pieces from the aircraft were recovered within the airport perimeter showing that they heard the bang before they had traveled 5 miles or 2 minutes. And they can't return to the airport to assess an obvious problem? It would have resulted in only a short delay. But I suspect that they wouldn't have departed again in that same aircraft.
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Several status messages on the right engine. Yeah that will be the old 2m squared of engine cowling missing problem, there was a company notam about that couple months ago.
When I worked there my experience was that the company was fairly supportive when dealing with events.
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Not that uncommon for bits to come off and damage wiring to (in this case non-critical) components.
From my analysis which is restricted by cursory knowledge of aviation, rapid degeneration can give a pilot(s) an extremely narrow window in which to make the correct decision and execute a recovery plan. Thread drifting slightly to illustrate this point (see T-Tail deep stall - Deep Stall), the pilots had less than 2mins to act upon the information they were receiving and make the correct decision. Sadly, they were unable to so by the time the CVR stopped recording.
So for the avoidance of any doubt, the packed sardine like 'chattel' in the rear, would rather not be used as flying guinea pigs and would prefer a firm 'decline' from the twin peaks in front, where there is any doubt in data emitted from these highly contiguous systems. Whilst this is easy for me to say in the anonymity of the PPRuNe Forum, I recognise that those that have a passion for flying heavy metal would like to remain employed and not have to succumb to the wrath of their managers. However they (you) should not be afraid to stand by that which you believe is correct on whatever day you choose to exercise such judgment. The 'chattle' in the back will appreciate it as they will have survived to join the contiguous aviation system on another day and more importantly so will your family, who will be spared the rhetorical management line, of what a great servant to aviation you had been.
Apologies to those who think I have spent in excess of my $0.02c.
Of course he took the advice under protest. This was taken unkindly and true enough some time later he found himself " failed " a sim check under dubious circumstances. THE MESSAGE WAS CLEAR.
You don't stop on a dark one lane road at night for every noise you hear in your car.
Decision making involves assessment and balancing of risks.
Armchair quarterbacking may be fun but it has no validity
Decision making involves assessment and balancing of risks.
Armchair quarterbacking may be fun but it has no validity
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Armchair quarterbacking may be fun but it has no validity
No pilot would have accepted the plane for flight dispatch in the same condition that it landed. And no pilot aware that the status annunciation related to a 3.7m2 piece of missing aircraft would have continued the flight. So if that is correct, the question remains as whether safety was compromised to satisfy the bean counting champions of Smithsonian economics.
Sax,
I disagree.
Yes a chunk of reverse duct had fallen off.
But the aircraft was airborne, and at some point was going to have to descend and land. That descent and landing were not going to be any more risky in Dubai than in Moscow.
Therefore, the only saftey related question was, was it any less safe to cruise for five hours before making the inevitable descent and landing?
The damage was done, parameters were stable, and there was no sign that the situation was deteriorating. What is it you envisage might have happened in cruise that might have led to an unsafe outcome, bearing in mind the aircraft had numerous diverion options en-route HAD anything gotten worse?
I disagree.
Yes a chunk of reverse duct had fallen off.
But the aircraft was airborne, and at some point was going to have to descend and land. That descent and landing were not going to be any more risky in Dubai than in Moscow.
Therefore, the only saftey related question was, was it any less safe to cruise for five hours before making the inevitable descent and landing?
The damage was done, parameters were stable, and there was no sign that the situation was deteriorating. What is it you envisage might have happened in cruise that might have led to an unsafe outcome, bearing in mind the aircraft had numerous diverion options en-route HAD anything gotten worse?
Down through Azerbajan, Uzbekistan, Iran, Kuwait, Bahrain, UAE.
Non-Etops, so never more than 420NM from an Adequate, though in this case, never more than 45 minutes from a company designated Alternate.
Non-Etops, so never more than 420NM from an Adequate, though in this case, never more than 45 minutes from a company designated Alternate.