Knights Of The Sky

Easy return to base:
After becoming heavily damaged, land and a field but do not turn off your engine.
Roll over the ground to a friendly base while avoiding the trenches.
Enemy planes can not shoot you while on the ground, but they will be in range of your guns.

Easy targets:
Press A after taking off to speed game time.
Your plane will be invincible to enemy guns.
Climb above the clouds and continue to gain altitude.
Eventually, all enemy aircraft will freeze in mid-air, making them easy targets.