Helicopter and plane cheats
BUZZOFF spawns the Buzzard, a small attack helicopter with missiles and guns. It's the most useful vehicle cheat in the game because it takes off from anywhere.
BARNSTORM (stunt plane) and FLYSPRAY (Duster crop plane) need room to take off, so spawn them on a long straight road or at the airport.
How to enter a GTA 5 cheat
PC: in Story Mode press ~ (left of 1), type the code and press Enter. PS and Xbox (and PC): open the in-game phone, go to Contacts → Keypad and dial the 1-999 number. Cheats don't work in GTA Online and switch off achievements and trophies until you reload a save.