After completing all of the missions in Broker (first island) and move on into Bohan, go to the Helicopter tours which is in the southern part of the island on a platform facing Broker. Hijack one of the choppers and take it to your apartment, try to land it on the parking area and if you do, save the game inside your apartment and you will now have a Helicopter for you to mess around with. Useful to get away from cops or to pick up friends or girlfriends quicker, only problem is landing.