The Gunney Attack Copter is an extremely nimble helicopter that comes armed with a minigun and a 57mm rocket pod (squared 2x3 pod?) for the driver and a heavy machine gun for a door gunner.
Although nimble and somewhat well-armed, its winch capacity and armor is extremely lacking, most armed vehicles are capable of destroying this helicopter.
It can be purchased from the Pirates' Shop and can be seen flying around the Pirates' Central Island Outpost and an unnamed island South of the Island where Lieutenant Falcón's Bunker is or was located.
Being a fast helicopter, the Gunney is best used for hit-and-run attacks or taking down infantry units with its minigun. Even an AI door gunner won't be able to use the MG to good effect unless the chopper is moving slowly or is relatively close, which risks the helicopter being shot down. The upside to the Gunney is that it is capable of out flying AA missiles, albeit with some skill.
The 6 rockets should be used very sparingly, they are enough to destroy three light tanks or 6 light vehicles (+ some possible collateral kills) if all rockets are direct hits. It is a bad idea to use the rockets against buildings since there are probably not even enough to inflict serious damage. A good tactic to use when destroying buildings is to winch a 500 gallon (or greater) fuel tank or an airstrike munition onto the target and then set it off with the minigun once the helicopter is at a safe distance.
When fighting this helicopter with anything weaker than tank shells, it is a good idea to aim for the cockpit to kill the pilot. It is impossible to kill an AI pilot with small arms fire unless the player is very close.