this would be very hard to do... it may be possible, because a parachutes engine must be turned on - otherwise it is collapsed and descends very very very rapidly - to turn the engine on you need some1 in the drivers seat, or just in the parachute basically. i am not sure how to do this - but one way...
_g1 = _this select 0
_parachute = createvehicle "parachute" [getpos g1 select 0, getpos g1 select 1, 50]
_jeep = createvehicle "jeep" [getpos _parachute select 0, getpos _parachute select 1, (getpos _parachute select 2)-1]
#loop
_jeep setpos [getpos _parachute select 0, getpos _parachute select 1, (getpos _parachute select 2)-1]
_howhigh = getpos _jeep select 2
?(howhigh =< 0.5):_jeep setdammage 0
?(howhigh =< 0.5):exit
~0.2
goto "loop"
so what this does, is firstly gets the positiopn of a gamelogic (that must be called to the script - when you execute it, put the name of the gamelogic in the [] - ie: [gamlogic] exec "para.sqs")
then, it makes sure your jeep stays 1 metre below the parachute at all times, and when the jeep is less than 50m cm off ground, it just ends the script...
btw - you have to rename script files .sqs for them to work - from johann's great tut
"remember:
.sq(m) = (m)ission
.sq(s) = (s)cript"
hope this helps...