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I specifically remember watching a flight test doing an aggressive takeoff and having the voiceover say that aircraft (two engine) need to have enough power to

by andy99 1y ago

I specifically remember watching a flight test doing an aggressive takeoff and having the voiceover say that aircraft (two engine) need to have enough power to take off full with one engine. And so can take off very steeply empty with two engines. Would that not also be the case for these planes?

justsid 1y ago
Yes, planes are designed to be able to take off with a lost engine. Usually this will extend the roll a bit because the speeds are different for engine out operations. This isn't the first MD-11 with an engine out take off, 5 years ago a FedEx MD-11 took off with a failure in the left engine[1]. Slightly different case, obviously, but it's certainly something that is accounted for when designing planes. [1] https://www.avherald.com/h?article=4dfd50b9&opt=0%20 https://www.avherald.com/h?article=4dfd50b9&opt=0%20
- bobthepanda 1y ago
  That being said, depending on how you lose the engine it can really mess up the takeoff; AA191 was lost when an engine detached from the plane on takeoff and took out part of the wing and hydraulic system with it. https://en.wikipedia.org/wiki/American_Airlines_Flight_191 https://en.wikipedia.org/wiki/American_Airlines_Flight_191
  - anonymars 1y ago
    > when an engine detached from the plane on takeoff... https://imgur.com/a/NYlrLYO https://imgur.com/a/NYlrLYO https://cdn.discordapp.com/attachments/757091156717862935/1435446018098331648/Screenshot_2025-11-04_193907.png?ex=690bfec8&is=690aad48&hm=7a065142e6359edd8e41f00ed0bf70e18c1bdffef825d01ba209a16d893af4d7& https://cdn.discordapp.com/attachments/757091156717862935/14... Source: https://reddit.com/r/flying/comments/1ooms7t/ksdf_accident/nn5wrfh/ https://reddit.com/r/flying/comments/1ooms7t/ksdf_accident/n...
- rob74 1y ago
  Yes, the takeoff roll will be longer, the climb will be much more shallow, but it is possible to take off with one out of two engines (and obviously also with two out of three). Of course, after successful takeoff, the plane should turn around and land as soon as possible. In this case however, with the wing already on fire (the engine is below the wing, so flames coming out of it would be visible behind and under the wing, not in front), I'm afraid that even if they had managed to take off, the fuel tank would have exploded or burned through the wing before they would have had a chance to land. Actually, this looks similar to the 2000 Concorde crash...
appreciatorBus 1y ago
All planes are definitely capable of taking off safely even if they lose an engine at the worst time. Whatever happened here, I would be shocked if lack of thrust in the 2 remaining engines was a significant factor unless someone really screwed up the load calculations and they were overweight for conditions.
- dboreham 1y ago
  Lack of thrust in the "taken out by debris" sense seems to be the case here.
- lazide 1y ago
  Single engine planes (GA, and some military planes) don’t handle this condition well at all. In fact, for awhile (maybe still the case), the #1 killer of skydivers was single engine failure on takeoff from the jump plane (and similar aircraft failures), not accidents ‘while skydiving’.
  - appreciatorBus 1y ago
    yes true, I guess I was assuming we were talking about commercial airlines :)

by andy99 1y ago

justsid 1y ago

Yes, planes are designed to be able to take off with a lost engine. Usually this will extend the roll a bit because the speeds are different for engine out operations. This isn't the first MD-11 with an engine out take off, 5 years ago a FedEx MD-11 took off with a failure in the left engine[1]. Slightly different case, obviously, but it's certainly something that is accounted for when designing planes. [1] https://www.avherald.com/h?article=4dfd50b9&opt=0%20 https://www.avherald.com/h?article=4dfd50b9&opt=0%20

bobthepanda 1y ago
That being said, depending on how you lose the engine it can really mess up the takeoff; AA191 was lost when an engine detached from the plane on takeoff and took out part of the wing and hydraulic system with it. https://en.wikipedia.org/wiki/American_Airlines_Flight_191 https://en.wikipedia.org/wiki/American_Airlines_Flight_191
- anonymars 1y ago
  > when an engine detached from the plane on takeoff... https://imgur.com/a/NYlrLYO https://imgur.com/a/NYlrLYO https://cdn.discordapp.com/attachments/757091156717862935/1435446018098331648/Screenshot_2025-11-04_193907.png?ex=690bfec8&is=690aad48&hm=7a065142e6359edd8e41f00ed0bf70e18c1bdffef825d01ba209a16d893af4d7& https://cdn.discordapp.com/attachments/757091156717862935/14... Source: https://reddit.com/r/flying/comments/1ooms7t/ksdf_accident/nn5wrfh/ https://reddit.com/r/flying/comments/1ooms7t/ksdf_accident/n...
rob74 1y ago
Yes, the takeoff roll will be longer, the climb will be much more shallow, but it is possible to take off with one out of two engines (and obviously also with two out of three). Of course, after successful takeoff, the plane should turn around and land as soon as possible. In this case however, with the wing already on fire (the engine is below the wing, so flames coming out of it would be visible behind and under the wing, not in front), I'm afraid that even if they had managed to take off, the fuel tank would have exploded or burned through the wing before they would have had a chance to land. Actually, this looks similar to the 2000 Concorde crash...

appreciatorBus 1y ago

All planes are definitely capable of taking off safely even if they lose an engine at the worst time. Whatever happened here, I would be shocked if lack of thrust in the 2 remaining engines was a significant factor unless someone really screwed up the load calculations and they were overweight for conditions.

dboreham 1y ago
Lack of thrust in the "taken out by debris" sense seems to be the case here.
lazide 1y ago
Single engine planes (GA, and some military planes) don’t handle this condition well at all. In fact, for awhile (maybe still the case), the #1 killer of skydivers was single engine failure on takeoff from the jump plane (and similar aircraft failures), not accidents ‘while skydiving’.
- appreciatorBus 1y ago
  yes true, I guess I was assuming we were talking about commercial airlines :)