You could do something like
(obviously adjust it to be called from a radio call)
player addAction ["Call in airdrop", "
openMap [true, false];
onMapSingleClick '
_height = 100;
_chute = ""B_Parachute_02_F"" createVehicle _pos;
_chute setPos [_pos select 0, _pos select 1, _height];
_vehicle = ""B_MRAP_01_F"" createVehicle _pos;
_vehicle attachto [_chute, [0, 0, 0]];
openMap false;
';
"];
Can't seem to get the chute to delete when the vehicle is close to the ground for some reason (somebody please complete that for me if you have the knowledge). Tried isTouchingGround and height < 5 but it's eluding my unfortunately due to repeated errors. I've given up on trying to make it work 100% but at least it gets the idea flowing.
Some notes are that it MUST be the vehicle attached to the chute and not the other way it around because otherwise the vehicle seems to just fall without the chute doing anything. Since the vehicle is attachTo'ed to the chute, it falls through the ground and gets damage on landing and that is why you need to delete the chute immediately at low altitude.