Comment by hugh-avherald
16 hours ago
V1 is the decision speed with respect to a single engine failure in a multi-engine aircraft. It's the speed below rotation speed at which the decision to abort safely can no longer be made.
Captains can make the decision to abort the takeoff in the case of absolute power loss or for 'failure to fly' (where the aircraft is clearly not going to fly, e.g. the elevator/pitch controls aren't responding). But the training is adamant: if you're uncertain what has happened after V1 you try to fly the plane away from the runway.
> abort safely
That's what I'm getting at. I want to abort unsafely. Imagine 400 meters of grass field after the end of the runway, and a water body. I'm asking wether such factors are accounted for, or if plane on ground beyond runway does-not-compute.
> I want to abort unsafely
I expect pilots are trained explicitly not to do that.
If you can't abort safely, than it follows that the safer course of action is to try to fly. I'm sure there are exceptions to that, but a pilot has barely seconds in which to decide if any of those exceptions apply, so they're not going to abandon procedure unless the situation is clear.
You should never plan to use your safety margin!
That "extra" 400m of grass? That's for all the other things that can still go wrong even when you follow procedure. e.g., you're below V1 so you abort takeoff, close throttles and hit the brakes. You should be able to safely stop on the runway.
But now your brakes fail because maybe the reason you had to abort was a fire that also managed to burn through your brake lines, or it started to rain just as you were taking off, or...
Now that's where the 400m of safety margin comes in to save your ass (hopefully). It's "extra", you don't plan on using it.