If you really do mean the general area, then use a switch trigger.
size: as you like, covering the general area of the waypoint
activation: chopper present (hit F2 and drag a line from the chopper to the trigger)
type: switch
synchro the trigger to the waypoint .... when the chopper activates the trigger it will be switched to the next waypoint.
If you're just worred about the flare that the heli sometimes does at a waypoint, apparently using flyinheight helps ... put it in the on activation field of the waypoint
chopper1 flyinheight 75
or whatever