MustangMan5's Note: I'm not sure if the title of the game is referring to the name of the aircraft, because the F22 isn't called the lightning, but is called the F22 Raptor.

Invincibility
While playing, press Ctrl-Alt-Shift-Home. A small green X will appear in the lower left-hand corner if you did it right.

Reload Ammo and Fuel
To reload your ammo and fuel, press Ctrl-Alt-Shift-Insert.

Stay off Enemy Radar
To avoid the enemy's radar, fly below 500 feet or above 50,000 feet.
MustangMan5's Note: I'm not too sure if this is true in the game or not, but that should only work on ground radar, and shouldn't have any effect on enemy aircraft radar. Try it anyways, maybe the creators of the game left out that detail, and this trick would work in both situations.