Re-arm and Refuel
To re-arm and refuel, press Ctrl-R while playing.
Glitch - Player Invisibility Unverified. To be invisible to your enemies you first need to select the 'Free Flight' mission. Once able to fly, crash into the first building you see (it doesn't matter which). As soon as you crash, end the mission.
The 'Free Flight' mission is a simulation, so you don't die. The game will register your chopper as dead in the next mission you attempt, and enemies will not fire on you. You'll need to do this every time you attempt a new mission.
Never Die
If your aircraft is heavily damaged and your sure it's not going to make
it, don't worry about it. Just exit the game NOT THE MISSION. Then just go
back into the game. When you exited it saved your pilot. You won't get the
points for the mission you were on, but it's better than having a dead
character.
