-Focus all your fire on any other helicopter that appears. To avoid the homing missiles that it fires, keep flying in small circles to keep them circling around you. Do not focus on the helicopter or the planes. Instead, just try to escape from the missiles while firing.
-When the enemy helicopter shoots homing missiles, fly in long horizontal ovals. The missiles will over steer. For example, when going to the left of the screen, immediately turn to the right, and vice versa.
-You can also try to shoot the enemy helicopter as fast as possible. If you dodge the missiles too much, the chopper will just send more missiles at you and you will miss chances to shoot all the planes.