11 ms·

Given that the aircraft itself seems otherwise undamaged, and people on the ground reported it 'rained' metal shards, I'd say these parts melted off the turbine

by krona 7y ago

Given that the aircraft itself seems otherwise undamaged, and people on the ground reported it 'rained' metal shards, I'd say these parts melted off the turbine and fell out. Significant but not catastrophic.

drdrey 7y ago
> significant but not catastrophic So... not great but not horrifying?
- rimliu 7y ago
  Not great, not terrible.
droithomme 7y ago
Insane comment!
jacquesm 7y ago
This ended well, fortunately. But that must have been pretty scary. A 787 that is out one engine will put extra load on the remaining engine, if that one has gone through a similar life as the one that just dropped bits all over the place I'd not wager on the remaining one being as safe as when it was last inspected. That's a lot of eggs in one basket. And they don't glide particularly well either, though there are some interesting stories around passenger aircraft and glide landings: https://en.wikipedia.org/wiki/Gimli_Glider https://en.wikipedia.org/wiki/Gimli_Glider But that one had a good 9000 meters more height to work with and it wasn't over densely populated area either.
- dmitrygr 7y ago
  > And they don't glide particularly well either Nonsense! Modern airlines glide exceptionally well. For example a 787 has a glide ratio of over 20:1 ! http://www.lissys.demon.co.uk/samp1/ http://www.lissys.demon.co.uk/samp1/ https://seekingalpha.com/article/2494925-boeing-the-airbus-a330neo-a-real-competitor-for-the-boeing-787-part-3 https://seekingalpha.com/article/2494925-boeing-the-airbus-a...
  - jacquesm 7y ago
    20:1 from 3000 meters gives you 60 km to line up and land, that's not as bad as a shuttle but not nearly as good as an actual glider. Personally I'd love to be on the ground in that situation. You can't just land a 787 on a bit of farmland. BTW if you have to deadstick a commercial plane then the 787 is probably the best, it has the best glide ratio of all commercial planes in service today. But I'd hate for that to be put to the test.
    - dmitrygr 7y ago
      That is a nonsensical comparison. Shuttle's glide ratio was 4.5:1 - barely better than a brick
      - jacquesm 7y ago
        Clearly the Shuttle's glide ratio was exceptionally bad, which is exactly why I used it for comparison. It still flies, after all.
      - dragonwriter 7y ago
        > Shuttle's glide ratio was 4.5:1 - barely better than a brick A brick has a glide ratio somewhere worse than 1:10; the shuttle (at subsonic speeds) is closer to a sailplane (~40:1, or ~9× better than the shuttle) than a brick (more than 50× worse).
        lucisferre 7y ago
        I'd like to see the footage of the brick tests.
        MertsA 7y ago
        https://www.youtube.com/watch?v=C-9fEoeNc3I https://www.youtube.com/watch?v=C-9fEoeNc3I
      - Terr_ 7y ago
- inferiorhuman 7y ago
  A 787 that is out one engine will put extra load on the remaining engine, if that one has gone through a similar life as the one that just dropped bits all over the place I'd not wager on the remaining one being as safe as when it was last inspected. That's a lot of eggs in one basket. That's why there are restrictions on which RR engines can be put in a 787 as well as a reduction in the ETOPS certification. There've been a few revisions to the Trent, and putting two of the more "unfixed" ones on one airframe is verboten.
  - hammock 7y ago
    That's a nice solution now that we know the engines need fixing. What about when they were first released? Are planes required to have one old-reliable engine?
    - kijin 7y ago
      That's what testing is for, although I'm not sure how much I'd like to trust Boeing and FAA with testing these days.
    - inferiorhuman 7y ago
      What about when they were first released? If memory serves Rolls placed the blame on the initial problems with the Trent 1000 on air quality in SE Asia (high sulfur content specifically). Which is to say, I don't get the impression that certification was done sloppily. Are planes required to have one old-reliable engine? Reliability is (theoretically) improved. From following threads on a.net and pprune it seems like Norwegian actually demanded new engines instead of repaired older ones. Personally, I'm of the mindset that engines are fantastically safe these days. Piston engines were notoriously unreliable, and even older jet engines were deemed unreliable enough to require more than two for oversea crossings. Look back to when the L-1011 was introduced. It was late due to problems with the Rolls Royce RB-211 (predecessor to the Trent family). Even after the L-1011 began service in-flight shutdowns were pretty common. What we're seeing with the 787 is seemingly less frequent and has provoked a stronger reaction. Of course GE (CFM) isn't immune to problems either and if you look back over their history they've had a few nasty problems including that fairly recent Southwest flight with a passenger fatality.
PhasmaFelis 7y ago
I'm honestly curious how part of the turbine melting and falling off in flight can be other than catastrophic.
- lb1lf 7y ago
  -Not an aeronautical engineer, but I know that a lot of thought goes into ensuring that pretty much no matter what happens to the engine, debris flying from it is not going to damage the structural integrity of the wing or fuselage. With redundant hydraulic/fuel/oil systems as well, much can happen to the engine without turning the airplane into a brick with passengers in it. That being said, I am glad I am not on the Trent 1000 design team.
isostatic 7y ago
> Significant but not catastrophic Depends where they land. Rain on a crowded playground and that's catastrophic for many reasons.
jaclaz 7y ago
"melted off" sounds a bit improbable, actual photos of the shards: https://roma.corriere.it/foto-gallery/cronaca/19_agosto_10/aereo-perde-pezzi-motore-che-precipitano-fiumicino-9d6e7edc-bb92-11e9-9f76-c4a17a124b8d.shtml https://roma.corriere.it/foto-gallery/cronaca/19_agosto_10/a...? they don't seem melted, rather broken/fractured.
salawat 7y ago
>Significant but not catastrophic Keep in mind, "catastrophic" is a loaded word in aviation safety parlance. It specifically means that failure of a system or component threatens total unrecoverable loss of the aircraft; and is the point where redundancy and fail-safe become required by law in order to certify. The regulation specifies no single point of failure should result in catastrophic loss. Any failure is news worthy, but this poster is on point. Chernobyl meme opportunity aside.
t0mas88 7y ago
I meant catastrophic in the way it is commonly used for aircraft failures: engine disintegrated and not repairable. Same term is used for a shattered turbine disc. It destroys the engine and is not contained so there is a risk to other components.

by krona 7y ago

drdrey 7y ago

> significant but not catastrophic So... not great but not horrifying?

rimliu 7y ago
Not great, not terrible.

droithomme 7y ago

Insane comment!

jacquesm 7y ago

This ended well, fortunately. But that must have been pretty scary. A 787 that is out one engine will put extra load on the remaining engine, if that one has gone through a similar life as the one that just dropped bits all over the place I'd not wager on the remaining one being as safe as when it was last inspected. That's a lot of eggs in one basket. And they don't glide particularly well either, though there are some interesting stories around passenger aircraft and glide landings: https://en.wikipedia.org/wiki/Gimli_Glider https://en.wikipedia.org/wiki/Gimli_Glider But that one had a good 9000 meters more height to work with and it wasn't over densely populated area either.

dmitrygr 7y ago
> And they don't glide particularly well either Nonsense! Modern airlines glide exceptionally well. For example a 787 has a glide ratio of over 20:1 ! http://www.lissys.demon.co.uk/samp1/ http://www.lissys.demon.co.uk/samp1/ https://seekingalpha.com/article/2494925-boeing-the-airbus-a330neo-a-real-competitor-for-the-boeing-787-part-3 https://seekingalpha.com/article/2494925-boeing-the-airbus-a...
- jacquesm 7y ago
  20:1 from 3000 meters gives you 60 km to line up and land, that's not as bad as a shuttle but not nearly as good as an actual glider. Personally I'd love to be on the ground in that situation. You can't just land a 787 on a bit of farmland. BTW if you have to deadstick a commercial plane then the 787 is probably the best, it has the best glide ratio of all commercial planes in service today. But I'd hate for that to be put to the test.
  - dmitrygr 7y ago
    That is a nonsensical comparison. Shuttle's glide ratio was 4.5:1 - barely better than a brick
    - jacquesm 7y ago
      Clearly the Shuttle's glide ratio was exceptionally bad, which is exactly why I used it for comparison. It still flies, after all.
    - dragonwriter 7y ago
      > Shuttle's glide ratio was 4.5:1 - barely better than a brick A brick has a glide ratio somewhere worse than 1:10; the shuttle (at subsonic speeds) is closer to a sailplane (~40:1, or ~9× better than the shuttle) than a brick (more than 50× worse).
      - lucisferre 7y ago
        I'd like to see the footage of the brick tests.
        MertsA 7y ago
        https://www.youtube.com/watch?v=C-9fEoeNc3I https://www.youtube.com/watch?v=C-9fEoeNc3I
    - Terr_ 7y ago
inferiorhuman 7y ago
A 787 that is out one engine will put extra load on the remaining engine, if that one has gone through a similar life as the one that just dropped bits all over the place I'd not wager on the remaining one being as safe as when it was last inspected. That's a lot of eggs in one basket. That's why there are restrictions on which RR engines can be put in a 787 as well as a reduction in the ETOPS certification. There've been a few revisions to the Trent, and putting two of the more "unfixed" ones on one airframe is verboten.
- hammock 7y ago
  That's a nice solution now that we know the engines need fixing. What about when they were first released? Are planes required to have one old-reliable engine?
  - kijin 7y ago
    That's what testing is for, although I'm not sure how much I'd like to trust Boeing and FAA with testing these days.
  - inferiorhuman 7y ago
    What about when they were first released? If memory serves Rolls placed the blame on the initial problems with the Trent 1000 on air quality in SE Asia (high sulfur content specifically). Which is to say, I don't get the impression that certification was done sloppily. Are planes required to have one old-reliable engine? Reliability is (theoretically) improved. From following threads on a.net and pprune it seems like Norwegian actually demanded new engines instead of repaired older ones. Personally, I'm of the mindset that engines are fantastically safe these days. Piston engines were notoriously unreliable, and even older jet engines were deemed unreliable enough to require more than two for oversea crossings. Look back to when the L-1011 was introduced. It was late due to problems with the Rolls Royce RB-211 (predecessor to the Trent family). Even after the L-1011 began service in-flight shutdowns were pretty common. What we're seeing with the 787 is seemingly less frequent and has provoked a stronger reaction. Of course GE (CFM) isn't immune to problems either and if you look back over their history they've had a few nasty problems including that fairly recent Southwest flight with a passenger fatality.

PhasmaFelis 7y ago

I'm honestly curious how part of the turbine melting and falling off in flight can be other than catastrophic.

lb1lf 7y ago
-Not an aeronautical engineer, but I know that a lot of thought goes into ensuring that pretty much no matter what happens to the engine, debris flying from it is not going to damage the structural integrity of the wing or fuselage. With redundant hydraulic/fuel/oil systems as well, much can happen to the engine without turning the airplane into a brick with passengers in it. That being said, I am glad I am not on the Trent 1000 design team.

isostatic 7y ago

> Significant but not catastrophic Depends where they land. Rain on a crowded playground and that's catastrophic for many reasons.

jaclaz 7y ago

"melted off" sounds a bit improbable, actual photos of the shards: https://roma.corriere.it/foto-gallery/cronaca/19_agosto_10/aereo-perde-pezzi-motore-che-precipitano-fiumicino-9d6e7edc-bb92-11e9-9f76-c4a17a124b8d.shtml https://roma.corriere.it/foto-gallery/cronaca/19_agosto_10/a...? they don't seem melted, rather broken/fractured.

salawat 7y ago

>Significant but not catastrophic Keep in mind, "catastrophic" is a loaded word in aviation safety parlance. It specifically means that failure of a system or component threatens total unrecoverable loss of the aircraft; and is the point where redundancy and fail-safe become required by law in order to certify. The regulation specifies no single point of failure should result in catastrophic loss. Any failure is news worthy, but this poster is on point. Chernobyl meme opportunity aside.

t0mas88 7y ago

I meant catastrophic in the way it is commonly used for aircraft failures: engine disintegrated and not repairable. Same term is used for a shattered turbine disc. It destroys the engine and is not contained so there is a risk to other components.