Qantas A380 uncontained #2 engine failure
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Flapping Madly
Engines on a big twin don't have to work any harder to get the thing in the sky.
They're just bigger engines.
The main difference is how well the planes fly when two engines stop obeying orders.
On a twin, not too well.
They're just bigger engines.
The main difference is how well the planes fly when two engines stop obeying orders.
On a twin, not too well.
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I'm not in the industry, but I just have an interest in aviation. My background is from motorsports (engines) .
In his post , # 910, " bearfoil " summed up the oil (lack of)> wear > vibration > failure sequence. In the AD relating to the spline wear, the frequency of inspections increased as the wear increased, right up to the " Immediate Change " mode, but the wear limits were over 2.0 mm from an unworn dimension of 2.65 mm.
Am I alone in thinking that such a problem should have elicited an priority " recall / fix" by RR on all the earlier engines in service, as opposed to allowing them to remain in service with such ( increasing ) rate of wear. Or would this have been an "Economics vs Engineering " based decision ?
I would be very interested to hear the thoughts of the professionals, especially the pilots. One thing is for sure, this thread has increased my appreciation for pilots and engineers ! And thanks for the many really insightful posts.
In his post , # 910, " bearfoil " summed up the oil (lack of)> wear > vibration > failure sequence. In the AD relating to the spline wear, the frequency of inspections increased as the wear increased, right up to the " Immediate Change " mode, but the wear limits were over 2.0 mm from an unworn dimension of 2.65 mm.
Am I alone in thinking that such a problem should have elicited an priority " recall / fix" by RR on all the earlier engines in service, as opposed to allowing them to remain in service with such ( increasing ) rate of wear. Or would this have been an "Economics vs Engineering " based decision ?
I would be very interested to hear the thoughts of the professionals, especially the pilots. One thing is for sure, this thread has increased my appreciation for pilots and engineers ! And thanks for the many really insightful posts.
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DevX:
Quite true. That's known as development testing, quite distinct from production testing.
But the "common knowledge" is that the T1000 engine that failed on 2 Aug was intended for a deliverable 787 (ship #9?). Why was this engine undergoing a development test, "well in excess of service conditions"? That doesn't seem a defensible practice.
What is not common knowledge to a large number of the public is that development engines are constantly run well in excess of service conditions for extended periods of time, thus failures can be a common occurrence dependant on the type of information required.
But the "common knowledge" is that the T1000 engine that failed on 2 Aug was intended for a deliverable 787 (ship #9?). Why was this engine undergoing a development test, "well in excess of service conditions"? That doesn't seem a defensible practice.
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There is a good letter in the latest Flight mago (16th Nov) saying what a good job the pilots did. There have been a few problems on Qantas aircraft lately; all have been handled well. Not much wrong with recruitment and training.
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CASA Interviewer: So Captain, Although you had no indication of fire or further systems degradation after the initial failure, you elected to make an approach and landing immediately without completing ECAM?
CAPTAIN: Well yes, it seemed like the thing to do at the time,......(Long draw on cigar)...... Safest place to be is on the deck.
CASA Interviewer: OK, Did you consider the Landing performance of the Aircraft and controllability of the aircraft prior to make this Approach?
CAPTAIN: Not required .......(another quick draw on cigar)..Hell I made it!
CASA: So were the Cabin Crew aware of the possibility of evacuating the aircraft upon landing or for that matter the other members of the flight crew?
CAPTAIN: Well sure....you'd have to be a moron to not appreciate the gravity of the situation.....(puff...puff)
CASA Interviewer: So the rushed approach, slightly long landing and ensuing runway over run don't worry you?
CAPTAIN: No not at all.......(long Draw).....Any landing you walk away from is a good one.
CASA Interviewer: You weren't aware of the fuel leaks from the left wing?
CAPTAIN: No like I said, I didn't complete ECAM
CASA Interviewer: So the post impact fire and loss of 440 lives seems like a good outcome to you?
CAPTAIN:.......(Long Draw on Cigar).... Like I said, I made it.
Love the Monday morning Quaterback! Gretschenfrage please don't be in command of a flight I'm paxing on!
CAPTAIN: Well yes, it seemed like the thing to do at the time,......(Long draw on cigar)...... Safest place to be is on the deck.
CASA Interviewer: OK, Did you consider the Landing performance of the Aircraft and controllability of the aircraft prior to make this Approach?
CAPTAIN: Not required .......(another quick draw on cigar)..Hell I made it!
CASA: So were the Cabin Crew aware of the possibility of evacuating the aircraft upon landing or for that matter the other members of the flight crew?
CAPTAIN: Well sure....you'd have to be a moron to not appreciate the gravity of the situation.....(puff...puff)
CASA Interviewer: So the rushed approach, slightly long landing and ensuing runway over run don't worry you?
CAPTAIN: No not at all.......(long Draw).....Any landing you walk away from is a good one.
CASA Interviewer: You weren't aware of the fuel leaks from the left wing?
CAPTAIN: No like I said, I didn't complete ECAM
CASA Interviewer: So the post impact fire and loss of 440 lives seems like a good outcome to you?
CAPTAIN:.......(Long Draw on Cigar).... Like I said, I made it.
Love the Monday morning Quaterback! Gretschenfrage please don't be in command of a flight I'm paxing on!
As simple SLF always slightly anxious about big planes with only two engines can I eagerly look forward to big planes going back to 4 engines each not having to work so hard to get the things into the sky?
Or not.
Or not.
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"wouldn't 4 engine planes in theory have twice the risk of this occuring than a twin?!"
Actually, you've hit on something--though it is not particularly relevant to the operation of large jets--that some pilots have used as an argument against light piston-engine twins: that not only are they barely flyable/controllable on one engine in critical states of flight, but you have -twice- the chances of an engine failing that you do in a single.
Actually, you've hit on something--though it is not particularly relevant to the operation of large jets--that some pilots have used as an argument against light piston-engine twins: that not only are they barely flyable/controllable on one engine in critical states of flight, but you have -twice- the chances of an engine failing that you do in a single.
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The problem with Monday morning quarterbacking is that it cuts both ways. It's easy to criticize GF for raising "what if" type of questions. But if that's a fair criticism of GF it's also fair to criticize those who praise the pilots without having all the details.
The ends don't justify the means. So what if they are landed safely. That might be as much due to luck as it was due to piloting skills. I doubt anyone on the forum knows yet one or the other.
So if it's fair to dismiss those who criticize then it's also fair to dismiss all the knobby-slobbers who praise.
The ends don't justify the means. So what if they are landed safely. That might be as much due to luck as it was due to piloting skills. I doubt anyone on the forum knows yet one or the other.
So if it's fair to dismiss those who criticize then it's also fair to dismiss all the knobby-slobbers who praise.
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stepwilk:
The case against light twins is really quite weak assuming a proficient pilot. No doubt once airborne and until reaching perhaps 1,500' or so, it is a "single" with distributed power.
After reaching that altitude the twin becomes much safer than a single assuming a proficient pilot. Sadly, proficiency is usually the weak link.
As to a four-engine jet transport you pay your dues, so to speak, with the greater risk of engine failure fairly early in the flight, but the payback is the far greater safety over an ETOPS bird as the four-engine airplane goes further and further towards the ETOPS ETP, and until ir again nears land. The argument against 4 engine jet transport is purely one of economics, not safety.
Actually, you've hit on something--though it is not particularly relevant to the operation of large jets--that some pilots have used as an argument against light piston-engine twins: that not only are they barely flyable/controllable on one engine in critical states of flight, but you have -twice- the chances of an engine failing that you do in a single.
After reaching that altitude the twin becomes much safer than a single assuming a proficient pilot. Sadly, proficiency is usually the weak link.
As to a four-engine jet transport you pay your dues, so to speak, with the greater risk of engine failure fairly early in the flight, but the payback is the far greater safety over an ETOPS bird as the four-engine airplane goes further and further towards the ETOPS ETP, and until ir again nears land. The argument against 4 engine jet transport is purely one of economics, not safety.
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"The case against light twins is really quite weak assuming a proficient pilot."
Absolutely agree. Assuming a proficient pilot, like all those Baron and 310 owners who go to FlightSafety for three days of emergency procedures every six months. When I was flying light twins (Shrike Commander, Aztec, Twin Comanche, 310Q mainly) I did do recurrent training, but I knew of few other people who did.
Absolutely agree. Assuming a proficient pilot, like all those Baron and 310 owners who go to FlightSafety for three days of emergency procedures every six months. When I was flying light twins (Shrike Commander, Aztec, Twin Comanche, 310Q mainly) I did do recurrent training, but I knew of few other people who did.
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Wait a second.
So they have a problem (to put it mildly), have issues with hydraulics and autobrakes, dump what fuel they can, then land with 100m to spare.
What would you have done differently?
Your options are simple.
1. Land heavy and risk going off the end.
2. Find a longer runway, land.
3. Get to MLW and land the thing, have a beer.
They couldn't possibly have known about the spar damage, and non of us know if it's even a real issue as far as the structure is concerned. I'd guess as it didn't fall out of the sky immediately/break off on the ground would suggest it's not critically damaged.
Don't get me wrong, I think all concerned have been very lucky, this could so easily have become another United 232 (many of the ingredients are there), but to coin a pprune phrase, the "holes in the cheese" were stopped from lining up by good aircraft design, a well trained crew, and having the right combination of people on the flightdeck at the time.
I can't see what else they could have done?
BHDH
So they have a problem (to put it mildly), have issues with hydraulics and autobrakes, dump what fuel they can, then land with 100m to spare.
What would you have done differently?
Your options are simple.
1. Land heavy and risk going off the end.
2. Find a longer runway, land.
3. Get to MLW and land the thing, have a beer.
They couldn't possibly have known about the spar damage, and non of us know if it's even a real issue as far as the structure is concerned. I'd guess as it didn't fall out of the sky immediately/break off on the ground would suggest it's not critically damaged.
Don't get me wrong, I think all concerned have been very lucky, this could so easily have become another United 232 (many of the ingredients are there), but to coin a pprune phrase, the "holes in the cheese" were stopped from lining up by good aircraft design, a well trained crew, and having the right combination of people on the flightdeck at the time.
I can't see what else they could have done?
BHDH
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The facts are that they landed safely with no injuries to pax or crew. They did exactly what they are paid to do in what now with hindsight were extremely difficult circumstances. There were probably other options that might have resulted in the same outcome, but they picked the one they considered best with the data they had. There were certainly many other options that would not have had as successful outcome.
The investigation will doubtless clarify what happened and the crews reactions in due course, so why speculate?
I for one would be happy to be flown by any of that crew.
The investigation will doubtless clarify what happened and the crews reactions in due course, so why speculate?
I for one would be happy to be flown by any of that crew.
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The maths seems interesting
Only an SLF so don't really know what I'm talking about, but since this whole incident came about with the initial failure of just one engine, wouldn't 4 engine planes in theory have twice the risk of this occuring than a twin?!
On the other hand, I'd guess there are a lot of silent motor outages that just remove an engine's thrust without any damage to anything outside the engine. In those cases a 4-engine plane ends up with 3/4 of its engines running, 3/4 of max thrust etc.
So, assuming that uncontained failures are very rare compared to silent failures, 4 engine planes have an advantage; if they are not so rare, then maybe 2-engine planes have an advantage -
Edmund
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At this stage of the debate would like to ask if the A380 is perchance overengineered
and more difficult to handle than older designs.
There are :
50 pages Ecam messages plus the associated check lists.But what to do with all this informations ? There is not one CB left in the cockpit.The
amount of PB is reduced.Computers are taking care of everything and on top they are all linked together-so they are dealing with the same (in this case wrong or missing) datas.But the guy who was writing the program is not on board...
If a simple job like shutdown engine No1 (four different devices installed to enable this) are all failing there might be something wrong with the whole issue.What about fuel dumping ?Just one simple valve per wing but to complicated to work properly in this serious situation?
And so on..
and more difficult to handle than older designs.
There are :
50 pages Ecam messages plus the associated check lists.But what to do with all this informations ? There is not one CB left in the cockpit.The
amount of PB is reduced.Computers are taking care of everything and on top they are all linked together-so they are dealing with the same (in this case wrong or missing) datas.But the guy who was writing the program is not on board...
If a simple job like shutdown engine No1 (four different devices installed to enable this) are all failing there might be something wrong with the whole issue.What about fuel dumping ?Just one simple valve per wing but to complicated to work properly in this serious situation?
And so on..