First (and this you probably already do) when shot down jump.
When hanging in the chute you will see a camera in the upper right corner.
Press the camera and you will get a crosshair and a fire button.
If you reach the ground without getting killed in the chute, you choose walk.
Look around you and you will find a tank. Walk to the tank and you will automatically enter it.
Good luck.
Ohh about the extre bombs... its only the morafs who can get bulletproof planes and extra bombs, but no more then 5 bombs at a time or the plane will be to heavy to lift off.
Edit:
Dang you Parrot, you write to fast