I know diddly squat about SP missions and very little about AI, thats a coop thing
As for players, then probably the best way to have them eject from the chopper is to have a script run on the individual clients waiting for a boolean to become true
eg
use a trigger activated when the chopper flys into the area or have the trigger run a server side script
Whatever you decide, at some point you need to broadcast a boolean variable
eg for script
getout = true; Publicvariable "getout"
or if a trigger simply
On activation: getout= true
then have clientside script running something on the lines
_____________________________________________________________
@ getout
whatever commands you need to get them all out
I know it doesnt help much, it sounds very much like a coop thing you are doing and i have little knowledge on these type of maps