Reach the indicated level to unlock the correspondinng weapons pack:

  Adaptive I Weapon Pack for F-4G Advanced Wild Weasel: Level 13 
  Air Domination I Weapon Pack for Mig-21 Fishbed: Level 11 
  Anti-Air Support Weapon Pack for EA-6B Prowler: Level 13 
  Anti-Air Support Weapon Pack for FA-18 RC: Level 12 
  Anti-Ground Superiority Weapon Pack for F-4G Advanced Wild Weasel: Level 12 
  Close Air Support I Weapon Pack for Mig-21 Fishbed: Level 10 
  Close Air Support Weapon Pack for EF-111A Raven: Level 13 
  Ground Assault I Weapon Pack for AV-8B Harrier: Level 13 
  Ground Assault II Weapon Pack for Su-25 Frogfoot: Level 11 
  Ground Suppression Weapon Pack for EF-111A Raven: Level 12 
  Level Bombing Weapon Pack for FA-18 RC: Level 13 
  Light Assault Weapon Pack for A-7B Corsair II: Level 10 
  Light Assault Weapon Pack for Su-25 Frogfoot: Level 10 
  Long Range Interception I Weapon Pack for Mig-25 Foxbat: Level 10 
  Multi-Role II Weapon Pack for Mig-25 Foxbat: Level 11 
  Multi-Role OO Weapon Pack for AV-8B Harrier: Level 12 
  Support Weapons Pack for EF-111A Raven: Level 4