Here, try this:
_i =0
#loop
_i = _i + 1
_camera camSetTarget YourHeli
_camera camSetRelPos [0, -5, 0]
; -> This sets the camera relative to your chopper (x, y, z).
_camera camSetFOV 0.624
_camera camCommit 0
~0.01
?(_i<= 200): goto "loop"
This assumes you have a camera created already. Play around with the x,y,z adjustments to get the right shot.
Change the max _i value to keep the shot for a longer period of time.
This small piece of code assumes the chopper doesn't change direction too much, preferably keep a straight line.
Gl!