Why was the Captain of Cathay Pacific flight 780 not able to shut down engine 1 and land with a more...
$begingroup$
In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots).
Why didn't they shut it off by turning the fuel pumps off? Is there a backup mechanism if the fuel valve fails like in this scenario?
safety jet-engine accident-investigation fuel-systems airbus-a330
New contributor
$endgroup$
add a comment |
$begingroup$
In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots).
Why didn't they shut it off by turning the fuel pumps off? Is there a backup mechanism if the fuel valve fails like in this scenario?
safety jet-engine accident-investigation fuel-systems airbus-a330
New contributor
$endgroup$
add a comment |
$begingroup$
In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots).
Why didn't they shut it off by turning the fuel pumps off? Is there a backup mechanism if the fuel valve fails like in this scenario?
safety jet-engine accident-investigation fuel-systems airbus-a330
New contributor
$endgroup$
In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots).
Why didn't they shut it off by turning the fuel pumps off? Is there a backup mechanism if the fuel valve fails like in this scenario?
safety jet-engine accident-investigation fuel-systems airbus-a330
safety jet-engine accident-investigation fuel-systems airbus-a330
New contributor
New contributor
edited 6 hours ago
psmears
25914
25914
New contributor
asked 10 hours ago
xMoooxMooo
262
262
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New contributor
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
You can find the full incident report here and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.
It was not until the aircraft [was] on the final descent for landing that
the Commander realised they could not reduce the thrust on the number
1 engine. The speed was not controllable and from that point, there
was no time for the crew to consider other strategy nor procedure to
cope with such emergency situation.
and more in the conclusion section...
t. At that stage, there was no time for the flight crew to consider other
strategy nor procedure to cope with such emergency situation. The
flight crew concentrated on flying the aircraft for a safe landing.
First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing may not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.
Considering that most airports have a bit (or a lot) of extra runway, EMAS systems and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
$endgroup$
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
|
show 1 more comment
$begingroup$
Engine #2 wasn't doing it's job either
Had the situation just been engine #1 stuck at high thrust, with engine 2 normally controllable, than what you describe would be a reasonable response to the situation. However, that was not the case with CX780 -- during approach, Engine #2 was stuck at 17% N1 (or rather below idle) and thus delivering effectively nil thrust.
As a result, the pilots dared not shut down engine #1 until they were safely stopped on the ground.
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
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active
oldest
votes
$begingroup$
You can find the full incident report here and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.
It was not until the aircraft [was] on the final descent for landing that
the Commander realised they could not reduce the thrust on the number
1 engine. The speed was not controllable and from that point, there
was no time for the crew to consider other strategy nor procedure to
cope with such emergency situation.
and more in the conclusion section...
t. At that stage, there was no time for the flight crew to consider other
strategy nor procedure to cope with such emergency situation. The
flight crew concentrated on flying the aircraft for a safe landing.
First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing may not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.
Considering that most airports have a bit (or a lot) of extra runway, EMAS systems and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
$endgroup$
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
|
show 1 more comment
$begingroup$
You can find the full incident report here and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.
It was not until the aircraft [was] on the final descent for landing that
the Commander realised they could not reduce the thrust on the number
1 engine. The speed was not controllable and from that point, there
was no time for the crew to consider other strategy nor procedure to
cope with such emergency situation.
and more in the conclusion section...
t. At that stage, there was no time for the flight crew to consider other
strategy nor procedure to cope with such emergency situation. The
flight crew concentrated on flying the aircraft for a safe landing.
First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing may not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.
Considering that most airports have a bit (or a lot) of extra runway, EMAS systems and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
$endgroup$
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
|
show 1 more comment
$begingroup$
You can find the full incident report here and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.
It was not until the aircraft [was] on the final descent for landing that
the Commander realised they could not reduce the thrust on the number
1 engine. The speed was not controllable and from that point, there
was no time for the crew to consider other strategy nor procedure to
cope with such emergency situation.
and more in the conclusion section...
t. At that stage, there was no time for the flight crew to consider other
strategy nor procedure to cope with such emergency situation. The
flight crew concentrated on flying the aircraft for a safe landing.
First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing may not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.
Considering that most airports have a bit (or a lot) of extra runway, EMAS systems and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
$endgroup$
You can find the full incident report here and this topic is touched upon briefly, but in short they had little to no time to entertain any other options but a full speed landing.
It was not until the aircraft [was] on the final descent for landing that
the Commander realised they could not reduce the thrust on the number
1 engine. The speed was not controllable and from that point, there
was no time for the crew to consider other strategy nor procedure to
cope with such emergency situation.
and more in the conclusion section...
t. At that stage, there was no time for the flight crew to consider other
strategy nor procedure to cope with such emergency situation. The
flight crew concentrated on flying the aircraft for a safe landing.
First off, the engine was throwing errors throughout the flight and they were talking to the maintenance team at other points. Ultimately, the proper steps were taken and everything was done by the book. They were prepared for an engine-out landing. When you have a runaway engine malfunction (or throttle stuck at full) shutting down prior to landing may not be the right decision if the running engine provides no immediate safety risk. If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again.
Considering that most airports have a bit (or a lot) of extra runway, EMAS systems and often land at the end of the runway, coming in overspeed and burning through your tires and brakes may be safer than cutting the engine and potentially falling short of the runway.
edited 5 hours ago
CJ Dennis
1073
1073
answered 10 hours ago
DaveDave
62.8k4112230
62.8k4112230
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
|
show 1 more comment
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
$begingroup$
Well I suppose you could establish glide distance to landing and cut fuel to the engine.
$endgroup$
– Joshua
7 hours ago
4
4
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
$begingroup$
Regarding the last paragraph... Any landing you can walk away from, and all that, huh?
$endgroup$
– T.J.L.
7 hours ago
2
2
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua - "If you shut down a problematic engine in flight you run the serious risk of not being able to get it started again." - What if you hit a sudden crosswind and have to abort the landing? I'd assume 'doing it by the book' never shuts down an engine that isn't e.g., on fire.
$endgroup$
– Mazura
4 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
$begingroup$
@Joshua … and if things are really screwed, you can't be 100% sure you are going to shut down either the engine you intended, or the correct one. We only know this was a "stuck valve because of contaminated fuel" with hindsight. The whole thing could have been caused by an electrical or computer problem, in which case the result of any control action is unknown until you try it and see what happens!
$endgroup$
– alephzero
3 hours ago
3
3
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
$begingroup$
@Joshua if you are on a 3 deg glideslope at reference speed with full flaps, if all the thrust is removed you are landing short in the housing development across the highway, unless you are already across the airport boundary, in which case you are landing in the approach lights or maybe if you're lucky you can stretch the glide to the runway and just land really hard.
$endgroup$
– John K
3 hours ago
|
show 1 more comment
$begingroup$
Engine #2 wasn't doing it's job either
Had the situation just been engine #1 stuck at high thrust, with engine 2 normally controllable, than what you describe would be a reasonable response to the situation. However, that was not the case with CX780 -- during approach, Engine #2 was stuck at 17% N1 (or rather below idle) and thus delivering effectively nil thrust.
As a result, the pilots dared not shut down engine #1 until they were safely stopped on the ground.
$endgroup$
add a comment |
$begingroup$
Engine #2 wasn't doing it's job either
Had the situation just been engine #1 stuck at high thrust, with engine 2 normally controllable, than what you describe would be a reasonable response to the situation. However, that was not the case with CX780 -- during approach, Engine #2 was stuck at 17% N1 (or rather below idle) and thus delivering effectively nil thrust.
As a result, the pilots dared not shut down engine #1 until they were safely stopped on the ground.
$endgroup$
add a comment |
$begingroup$
Engine #2 wasn't doing it's job either
Had the situation just been engine #1 stuck at high thrust, with engine 2 normally controllable, than what you describe would be a reasonable response to the situation. However, that was not the case with CX780 -- during approach, Engine #2 was stuck at 17% N1 (or rather below idle) and thus delivering effectively nil thrust.
As a result, the pilots dared not shut down engine #1 until they were safely stopped on the ground.
$endgroup$
Engine #2 wasn't doing it's job either
Had the situation just been engine #1 stuck at high thrust, with engine 2 normally controllable, than what you describe would be a reasonable response to the situation. However, that was not the case with CX780 -- during approach, Engine #2 was stuck at 17% N1 (or rather below idle) and thus delivering effectively nil thrust.
As a result, the pilots dared not shut down engine #1 until they were safely stopped on the ground.
answered 3 hours ago
UnrecognizedFallingObjectUnrecognizedFallingObject
8,21732278
8,21732278
add a comment |
add a comment |
xMooo is a new contributor. Be nice, and check out our Code of Conduct.
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