Here are a few parts that I think would make this game even more amazing:

Bomb bay fuselage part
Tank tracks
Propellers with high torque and quickly variable thrust/speed (like those on a multirotor)
Electric motors, propellers, etc. — and solar panels, batteries
Cockpit instruments, such as artificial horizon, speedometer, etc.
Controllable autopilot (ex. go east at 5,000 ft, then north at 6,000 ft.)

Thanks for reading.