Maybe this example mission will help.
You may have to play it a few times ( its only a minute long ) to see where my issues are. For instance sometimes the helo will blow up on a tree before the final height trigger activates so the crew and burning game logic will not teleport at all.
I think because the helo blows up before it reaches the trigger height so the helo no longer exists.
The idea is that the player can witness some tail rotor failure then go see if any crew survived. The eventual idea is to use a distance trig at the "wreck" game logic to give the player a new objective.
Or have some documents on one of the crew that activates a trigger when they are picked up. That's another issue though that I can learn how to do next.
http://www.sendspace.com/file/4y2gy3