You did read the post by Cory B?
Give the chopper a name in its name field via the unit placement dialog.
Create a trigger close to it.
The condition that will activate the trigger:
typeOf (driver helochopter) != "SoldierWPilot" ...helochopter presumably represents the name of the chopper given in the first step. "SoldierWPilot" is the classname of the pilot model. So this line is checking if whoever gets in the chopper is a pilot or not.
Presuming the condition is true and the person getting in the pilots seat is not "SoldierWPilot", then the OnActivation line will run:
(driver helochopter) action ["Eject", helochopter] ... Which means he is automatically ejected.
If on the other hand the person getting into the pilots seat is "SoldierWPilot" then the trigger will not fire.....Hopefully
Unfortunately it doesn't seem to work.
Planck