Hey CopyrightPhilly,
I think you need to seperate your commands. I think (not too sure, though) you can do this with an and:
while "_loops > _counter" do {_unit = _cargo select _counter and _unit action ["eject", _chopper] and _counter = _counter + 1 and ~1}
or you may have to use a comma:
while "_loops > _counter" do {_unit = _cargo select _counter, _unit action ["eject", _chopper], _counter = _counter + 1, ~1}
Just a suggestion, I may be totally wrong, I have never used the while do command before
-Student Pilot