Ace Combat: The Belkan War Cheats

In mission 3 shoot down the Rot squadron.

Beat campaign mode on any difficulty with all three different ace styles.

Unlocking the Supreme Aces and regular Ace medals are different. To unlock the stadard ace medal, you must clear the game with the arrow in that ace zone. To unlock the Supreme Ace mdeal, you must be as far into the zone as possible

Complete the game once with any difficulty to unlock the F-22A. Complete the game twice with any difficulty but with a different ace style to unlock the X-02.
Obtain all supreme ace medals to unlock the ADF-01.
You will still need to buy those planes after being unlocked.

Normally, you have to beat the game twice to unlock this plane but if you have Ace Combat 4 data, it is much easier.

With AC5 save file in the same memory card, to get a Falken for purchase, just beat the game in all 3 Ace Styles in any difficulty. It's a lot easier than the normal way (obtain 3 Supreme Medals).
Note that the save file must have the same language (AC5 JP save file only works for AC Zero JP)

Obtain S ranks in all 55 missions on ace difficulty to unlock a new hangar, decorated with Ustio and Galm team flags.

Complete campaign mode on any difficulty as a Knight, Soldier, and Mercenary to unlock that respective paint scheme

In this mode, you may play any previously completed missions. You will still receive credits and can improve your rank for the mission, but your Ace Style will not change.

Defeat all major (mission-required) enemy Ace Squadrons.

Clear the single player Campaign once on any difficulty and with any Ace Style to unlock the Scene Viewer and Music Player in the Ace Style>Gallery.

Complete campaign mode on certain difficulties to unlock SP colour schemes