1. open the editor
2. create a squad (player = squad leader)
3. create a chopper nearby the squad f.e. Mohawk or MH-9 (they have steerable
parachutes in their inventory by default)
4. preview the mission
5. choose one squad member with pressing the F2...F12 keys
6. choose the action command with pressing the 6 key and you will find following
entry "Open Steerable Parachute"