Auto Gyro
Successfully complete all levels in sky canvas mode with more than 90 points to unlock the Auto Gyro.

Corsair
Accumulate enough acrobatic points in adventure mode to have ten of your mission grades marked with circles to unlock the Corsair.

Gold UFO
Successfully complete all levels in target mode with a gold rank to unlock the Gold UFO.

Me-262
Successfully complete adventure mode to unlock the Me-262.

Silver UFO
Successfully complete all levels in the adventure mode with an A rank to unlock the Silver UFO.

Stealth Fighter
Successfully complete all levels in adventure mode with a total time of 10 minutes or less to unlock the Stealth Fighter.

Pontoons
Successfully complete the Stormy Seas level in adventure mode by landing on an aircraft carrier. The pontoons will allow your aircraft to land on the water.

Custom parts
Successfully complete all adventure mode levels with at least a B rank to unlock custom parts.

Swordfish third wing
Land at the Mid-Air Rendezvous alternate landing strip in adventure mode to find a wing that can be attached to the Swordfish to convert it into a triplane.

Note: Unlock the Special Radar in target mode to make it easier to find the landing strip.

Shinden Part Locations: [Submitted by:Ross Wenman]
The four shinden parts are hidden throughout adventure mode on alternate landing strips although you can get the parts on free flight.
Note: Unlock the special Radar in target mode to make it easier to find the landing strips.

Right wing:
The Adventure Begins level alternate landing strip.

Left Wing:
The Labyrinth alternate landing strip.

Fuselage:
The Towers Of Terror alternate landing strip.

Jet Engine: [Submitted by:Ross Wenman]
The Great Divide alternate landing strip.