Here is the full list of all 24 Air Conflicts: Secret Wars achievements worth 1,000 gamerscore.
Every mission completed
Chapter VII Completed
All planes unlocked in single player campaign
Chapter VI Completed
Chapter V Completed
Chapter IV Completed
Chapter III Completed
Enemy aircraft shot down in single player with rocket at great range
100 aircraft shot down in Campaign Game
Chapter II Completed
Chapter I Completed
100 ground units destroyed in Campaign Game
Place in top half in Deathmatch with at least 6 players
Place first in Deathmatch with at least 6 players
Kill 100 players in multiplayer
Play 50 multiplayer matches
Kill 5 players in multiplayer without dying
Kill 10 players in multiplayer without dying
Win 5 multiplayer matches with RAF team
Win 5 multiplayer matches with Red Air Force team
Win 5 multiplayer matches with Luftwaffe team
Win 5 multiplayer matches with any Great War Team
Perform long range Rocket Kill in Multiplayer
Perform extra long range Rocket Kill in Multiplayer