Here are a few cheat codes I have. They need to be entered at the main menu.

All Planes and Missions: Hold LT + RT then press X, LB, RB, Y, Y, RB, LB, X

Vampire MK1: Hold LT + RT and press LB, LB, Y, Y, X, LB

(You need to have unlocked the Vampire for the above cheat code to work)

God Mode: Hold LT then press LB, LB, RB. Release LT and then hold RT while pressing RB, RB, LB