Enter the password "GTGAUO". Now land your plane for a surprise. After that, hit b+c at the same time and it will take you to a screen at the top of that page. Some words will be highlighted bring the green highlight down to where it says unlimited ammo. There are a few more cheats also make it so you see a little x beside it and you will have those cheats.
Cheat mode
Press B + C during game play. A menu with unlimited firepower, invincibility, automatic targeting, and other options will be displayed.
Harder Game
For a real challenge, at the password screen, enter the password "GPRJCM". You'll face an aerial onslaught of F-22's, KC-135's and MIGs.
Level passwords
Mission
USA
Iraq
Korea
Russia
Aces
1
0HG021
C6G022
7E002E
HJ0024
LJG02V
2
0PG06D
CEG06L
7M006Q
HR412H
LNG067
3
0TG0E0
CIG0A4
7Q01AA
I701QI
LRGOAN
4
11G0I2
CM60EC
8201QS
IB02EI
LVG0EU
5
15G0MA
CUGO1O
8601U4
IF02U6
M3G010
6
19G0UM
D2G0U2
8A022D
8A022D
M7G0UG
7
1DG163
D6O1EV
8I0TE8
8I02E8
MBG16T
Veteran aces
Enter MGGIGJ as a password at the password screen.
Cheat Menu...