Qantas A380 uncontained #2 engine failure
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Joyce confirms that in yesterday's incident the crew were unable to shut down the A380's number one engine after making their emergency landing back at Singapore, but he says that up until that point the engine had responded to control inputs normally.
Qantas may resume A380 operations within 48h
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Airbus A380 passes first major test with flying colours.
I think the aircraft, aircrew and even the engine have done extremely well. The engine lunched itself in spectacular fashion yet with non fatal damage to the aircraft and with no fire. When you think that Concorde was finished by a lump of rubber and of more than one aircraft burnt out from a single popped combustion chamber it does show the A380 in good light. Luck as well I know but not just luck. It is a bit sad that Rolls Royce are suffering more because the aircraft did make it back as the damaged engine is there in plain sight during the initial media hysteria. It is unfortunate that the less we know the more we need to talk.
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OK, so why are we suddenly obsessing on the necessity to add another (complicated) engine control system to aircraft? I don't understand the fuss - sure the incident we are discussing here led to a situation where #1 could not be shut down, however I question whether this was a significant safety issue? (At least compared to #2 blowing a good portion of itself into little pieces and flying around making holes in things).
OK, in this case, they were very lucky, but, what would have happened if #1 had been affected in some way by #2 and needed to be shut down? There would have been a lot of things flying this way and that when it failed.
I don't know that you can say, for this engine type, that we may not see a similar thing happen in the future some time. How many times have particular aircraft types have had the similar failures until an investigation and fix solved and identified the problem. At this stage the investigation is still ongoing and no cause of the incident has been established, so therefore if it was "just one of those things", then the odds aren't very good, considering the limited number of hours these aircraft have been flying with this engine configuration. That is for the investigators to determine. Until then, I don't know that Qantas or Singapore airlines are going to be too happy having their fleet of heavy loaders sitting around doing nothing until it is all figured out. If it was a crack or something else that layed undiscovered then fair enough, but at this stage there just isn't enough information to even say that, or it could be inherent in the design of the engine.
Yes, it does complicate things and yes it targets the one in a zillion chances of it happening. What I am not saying is that it should be adopted and every aircraft should have it fitted. What happened wasn't meant to happen either statistically, but the number came up. What would be interesting to do is some research into, is how many new engine types had problems in the early days.
Agreed it was a pure containment issue, and may never again happen, I guess I was coming at it from the angle of solving the problem of what it caused, and what potentially could have gone wrong, had the containment issue caused other problems than it did. Yes, also agree that the idea may never need to be used if implemented ever again. That wasn't the point of my discussion.
I think someone else proposed the only solution that makes any sense to me - a prominent red hatch on the engine pylon, with a big red "OFF" lever behind it, and long pole with a hook on the end of it...
Waste of bandwidth... everything is...
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Raggy
"..... what would have happened if #1 had been affected in some way by #2 and needed to be shut down?"
Food for thought indeed if anyone still wants a 2-engines vs 4-engines debate.
The latter fly very badly on two engines. Twins fly very well on one engine.
Food for thought indeed if anyone still wants a 2-engines vs 4-engines debate.
The latter fly very badly on two engines. Twins fly very well on one engine.
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Please excuse a question from a layman but does the purported inability to shut down number 1 necessarily mean that it would've been unresponsive to changes in thrust setting, and would've been at its last known setting (climb power?) before the failure of number 2 and associated damage?
If so, how would this anomalous status of number 1 affect the subsequent approach and landing? Is the scenario of a three engine landing with one of those engines stuck on climb thrust one that comes up in simulator training and is covered in documentation? Or would the crew have been largely "improvising" with this approach?
If so, how would this anomalous status of number 1 affect the subsequent approach and landing? Is the scenario of a three engine landing with one of those engines stuck on climb thrust one that comes up in simulator training and is covered in documentation? Or would the crew have been largely "improvising" with this approach?
Do a Hover - it avoids G
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Anybody thought that if you are foaming No2 and for whatever reason you splash some in No1 it is only polite to wash No1 there and then?
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Engine Non-Containment
As part of my thesis at Cranfield, and at the request of the UK AAIB, I completed an analysis on the regulations pertaining to engine non-containment. The objective was to determine whether the failure modes demanded a change in the model as depicted by the then current regulations (1995). A central data base exists for the collection of data relating to each un-contained event so that regulatory design engineers and engine OEMs can assess what changes should be introduced to the regulations to maintain the probability of experiencing an uncontained event to the required level (which of course is ultimately what aircraft are designed around – probability that is !).
Un-contained events are more frequent that the general public would probably like to understand, and have occurred in almost every major engine type at some point throughout their production life cycle. The reason for the liberation of the material is though different for each event.
I am running from memory but I don't believe that the regulations, as they were back in 1995, demanded that there be an assumption that the fan blade, by itself, is more likely to fail than a turbine disc. However there is a higher probability that the fan blade will be damaged by an external influence (i.e. bird strike) and therefore fail - hence the containment ring.
The regulations are extremely precise about the quantity of mass, exhibiting specific energy levels, that need to be contained. Large pieces of turbine or compressor discs will not be contained as if they were the containment shield would be of such weight to make the aircraft un-economical. The fan blade shield for example already consists of a wrap of Kevlar a couple of inches thick. The regulations, for material that is liberated in an assumed dispersion zone, subsequently require that the airframe demonstrate a sufficient level of redundancy should such an event occur. This is achieved by the positioning of certain systems in physical locations that will demonstrate, when the material dispersion model is run, that a regulated level of redundancy is available, permitting the crew to retain control of the aircraft.
In addition the airframe and engine OEMs have to demonstrate that, with the current design and future maintenance and inspection philosophy (i.e. the maintenance and engine shop visit programme and inspection requirements) that the probability of the disc being released, is (from memory) and causing a fatal accident, in the order of 10 to the power of -6. This figure assumes that there are no flaws or errors built into the design and that all scheduled, mandated inspections and maintenance has been completed.
Most disc non-containments occur as a result of a deviation from the inspection or maintenance requirements or from the disc exceeding its operational limitations. The problem may be further compounded by an up-stream failure of a blade causing further damage downstream. Ocassionally design (CF6) and material flaws (Sioux City DC10) are also causal factors.
Some older types of aircraft, such as the B737-200, simply do not comply with the current EASA requirements in this respect, but modifying them would be too costly.
In short we should not be surprised when material, that exceeds the regulatory model, is liberated from an engine. Disks will continue to be ejected so long as we continue to operate aircraft.
Airbus should though be congratulated as they have demonstrated, very publicly, that the 380 has the required level of redundancy. Most events like this go un-recorded - much to the relief of manufacturer's around the world.
Now, can anyone calculate what is the probability is of a passenger being involved in an un-contained engine failure and then, once rescued by a passing QF744, be diverted for a second time, due to yet another engine failure of a different type, back to the same departure point - twice in succession ? I give up at that point.
Un-contained events are more frequent that the general public would probably like to understand, and have occurred in almost every major engine type at some point throughout their production life cycle. The reason for the liberation of the material is though different for each event.
I am running from memory but I don't believe that the regulations, as they were back in 1995, demanded that there be an assumption that the fan blade, by itself, is more likely to fail than a turbine disc. However there is a higher probability that the fan blade will be damaged by an external influence (i.e. bird strike) and therefore fail - hence the containment ring.
The regulations are extremely precise about the quantity of mass, exhibiting specific energy levels, that need to be contained. Large pieces of turbine or compressor discs will not be contained as if they were the containment shield would be of such weight to make the aircraft un-economical. The fan blade shield for example already consists of a wrap of Kevlar a couple of inches thick. The regulations, for material that is liberated in an assumed dispersion zone, subsequently require that the airframe demonstrate a sufficient level of redundancy should such an event occur. This is achieved by the positioning of certain systems in physical locations that will demonstrate, when the material dispersion model is run, that a regulated level of redundancy is available, permitting the crew to retain control of the aircraft.
In addition the airframe and engine OEMs have to demonstrate that, with the current design and future maintenance and inspection philosophy (i.e. the maintenance and engine shop visit programme and inspection requirements) that the probability of the disc being released, is (from memory) and causing a fatal accident, in the order of 10 to the power of -6. This figure assumes that there are no flaws or errors built into the design and that all scheduled, mandated inspections and maintenance has been completed.
Most disc non-containments occur as a result of a deviation from the inspection or maintenance requirements or from the disc exceeding its operational limitations. The problem may be further compounded by an up-stream failure of a blade causing further damage downstream. Ocassionally design (CF6) and material flaws (Sioux City DC10) are also causal factors.
Some older types of aircraft, such as the B737-200, simply do not comply with the current EASA requirements in this respect, but modifying them would be too costly.
In short we should not be surprised when material, that exceeds the regulatory model, is liberated from an engine. Disks will continue to be ejected so long as we continue to operate aircraft.
Airbus should though be congratulated as they have demonstrated, very publicly, that the 380 has the required level of redundancy. Most events like this go un-recorded - much to the relief of manufacturer's around the world.
Now, can anyone calculate what is the probability is of a passenger being involved in an un-contained engine failure and then, once rescued by a passing QF744, be diverted for a second time, due to yet another engine failure of a different type, back to the same departure point - twice in succession ? I give up at that point.
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RBR .....
unf***ing likely, maybe idle tho.
don't know where you heard that, but they probably shut down a second engine on opposite side of plane for even distribution of engine power....
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Boomerang Butt...
Perhaps, unless the birds just collided with are seagulls. Hit a flock of them on approach to LAX in the late 1980's. Injested by all three engines of a DC-10. We smelled fish-birds on the flight deck about 2 seconds after impact. It was a flock of maybe 20-30 seagulls. The engines didn't react one iota. They were at stable fully configured for landing at about 1500 feet and probably 150+- knots.
You usually get comments from the pax of a smell of "roast chicken" after a bird is ingested, and I haven't seen any suggestion of that. Not impossible, but unlikely.
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Spot on, VR-HHE.
By the way, the section of the rotor disk recovered looks perfectly in line with current models, which mandate the consideration of a one-third portion of the disk, in addition smaller fragments with a different distribution.
By the way, the section of the rotor disk recovered looks perfectly in line with current models, which mandate the consideration of a one-third portion of the disk, in addition smaller fragments with a different distribution.
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Greynerd
why are you talking about Ingestion of FOD again ? A380's are a Code F aircraft and can operate from 60 wide runways. They can operate from 45m width runways under a certain AACG varaince given by the countries aviation authority but only if the shoulders are 75m wide.
Singapore has 60m wide runways which gives the A380 plenty of room so as not to pick up dirt etc from the grass edge. The outboard is at 25m.
SEcondly if it had picked up FOD it would have been realised by the flight crew a lot sooner and I have not seen any pics of fan blade damage which would have supported this theory and they sure would have been published by Now.
Why do people always think its a birdstrike or FOD .
why are you talking about Ingestion of FOD again ? A380's are a Code F aircraft and can operate from 60 wide runways. They can operate from 45m width runways under a certain AACG varaince given by the countries aviation authority but only if the shoulders are 75m wide.
Singapore has 60m wide runways which gives the A380 plenty of room so as not to pick up dirt etc from the grass edge. The outboard is at 25m.
SEcondly if it had picked up FOD it would have been realised by the flight crew a lot sooner and I have not seen any pics of fan blade damage which would have supported this theory and they sure would have been published by Now.
Why do people always think its a birdstrike or FOD .
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VR-HHE,
There is a quote in this Bloomberg article which says that uncontained failures happen around once a year on average. Does that match up with what you found during your research?
Un-contained events are more frequent that the general public would probably like to understand, and have occurred in almost every major engine type at some point throughout their production life cycle.
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Code:
Perhaps, unless the birds just collided with are seagulls. Hit a flock of them on approach to LAX in the late 1980's. Injested by all three engines of a DC-10. We smelled fish-birds on the flight deck about 2 seconds after impact. It was a flock of maybe 20-30 seagulls. The engines didn't react one iota. They were at stable fully configured for landing at about 1500 feet and probably 150+- knots.
