Comment Code (Score 5, Informative) 558
Aside from any code with the purpose of fascilitating a "shutdown" of the plane, the code for the radar data processing is what the US is most concerned to keep a well guarded secret.
Also, 90% of the code for the F22 is written in Ada.
http://www.globalsecurity.org/military/systems/air craft/f-22-avionics.htm