I kinda give it up now.
My problem evertime I design an aircraft or helicopter and want it go faster by adding airship thrusters I end with the problem that pressign forward does accelerate the ship(heli, yet it cannot hold height then, (no matter how many upwards rotors I add) it will then always start to slightly sink
Now I Can surely make a thruster pointing slightly downwards so the vehicle keeps level when steering forward, but this suddenly stops the vehicles ability from flying forwards and downwards via pressing alt
that kinda really sucks as it does not allow a fast vehicle with proper 3 dimensional movement. So is there any way to achieve that?