Top Gun: Combat Zones
On all levels that contain multiple aircraft bogies, the best way to take them out is to fly low to the ground and swoop up to take one out at a time.
Flying close to the ground causes the anti-aircraft guns to overshoot your plane. They cannot fire below a certain point.
All Levels & Planes:
At the player name screen, enter SHPONGLE
Thanks to Revolution readers The Gooseman and Jim!