First of all thanks for your answer again! Unfortunately it does not quit seem to work. I think tha problem is, that
FVector forwardVector = GetActorForwardVector();-
FVector upVector = GetActorUpVector();
is not actually the velocity. Its just the vector pointing up and forward from the actor I think. So what I did in my original code was just apply the force on to that vector so the plane would move in the direction of that Vector. For example GetActorUpVector is just the direction I applied the force to. What I wanted to do was apply a force to the actor up vector based on the planes speed. My Airplane has physics enabled and I do have a key that generates a forward thrust as you said. But the mechanics should be similar to a real plane so even when there is no thrust and the airplane falls straight down I should be able to stop the plane from free falling and get it into some sort of gliding behavior by pointing the nose in the direction it falls. Now GetActorVelocity did work kind of, but It ignored the current rotation of the airplane. For example the plane might be upsidedown or something, but as long as it had velocity in the global x direction a force would be applied to the ActorUpVector. But the thing is that I basically need to know the velocity form the perspective of the airplane itself. Maybe in other words: How much wind is hitting straight on the planes nose (I know that’s not what velocity is but maybe that gives an idea :D) Another example: The plane is completely horizontal and just sits in midair but falls down (because physics are enabled) when I press start/beginplay. Now ideally if I don’t press anything and leave the plane falling down nothing should happen and no force should be applied because from the planes perspective there is no velocity in the nose direction of the plane( local x-axis). I hope this makes sense and I hope my logic is not flawed :D! Again thanks for your help !