Thanks for the reply, I found out that I just had a wrong name for something in the trigger. So both the original and the correction work.
BTW, I now have a cool trigger to have a light next to a service point turn off when planes or helicopters come close, turn it on during the repair, and back off again when they start to leave. Had to use isEngineOn instead of the getpos height. It looks like this:
Condition:
((("Plane" countType thislist > 0) || ("Helicopter" countType thislist > 0))) && (isEngineOn (thislist select 0))
On Act:
tlight1 action ["lightOff", tug1];
On Dea:
tlight1 action ["lightOn", tug1];
tlight1 is the game logic orginally used to turn the lights on in the empty tug.
tug1 is the tug.