To unlock the planes below, fulfill the objectives listed:

A-10 - Do all ground training objectives in Training Mode.
Blue Impulse T2 Trainer - On the bay map, grab the Blue Impulse logo under the bridge during Free Flight Mode.
Blue Impulse F-86 Fighter - On the island map, grab the Blue Impulse logo during Free Flight Mode.
C1 - Beat maneuver objectives at Aero Meet.
F-86 Fighter - Log one hour of playing time in Training Mode.
F-104J fighter - Reach Mach 2.0.
F-105 Drone - Fly 50,000 feet in Training Mode.
F-14B Test Bed - Beat Reconnaissance Mission 2.
F-15 Aggressor 1 - Log 50 kills.
F-15 Aggressor 2 - Log 100 kills.
F-15C - Finish ACM objectives at Aero Meet.
F-15J - Finish 10 scrambles.
F-2B - Finish 50 scrambles.
Oh-6 - Finish helicopter training.
Su-27 Fighter - Beat Reconnaissance Mission 3.