In Ace Combat: Assault Horizon for the PS3 and Xbox 360, there are quite a few call signs you can unlock by completing various tasks.
Here are the call signs you can unlock, and what you have to do to unlock them.
Antares – Earn 1,000,000 points
Aquila – Get one Survivor reward by staying alive the longest amount of time in a round
Burner – Win twenty Capital Conquest matches
Cougar – Shoot down over 100 enemy players online
Dragon – Win ten Capital Conquest matches
Falco – Get one Ace Striker reward by getting the most ground kills in a round
Galm – Get five Ace Pilot rewards by getting the most air kills in a round
Garuda – Complete Campaign Mode
Ghost – Shoot down over 100 enemy players online using an attack helicopter
Gryphus – Get five Hero rewards by performing the best in a round
Mobius – Get one Hero reward by performing the best in a round
Mohawk – Earn 100,000 points
Phoenix – Place first in a Deathmatch
Racer – Use DFM Support more than fifty times in multiplayer
Renegade – Earn 300,000 points
Scarface – Get one Ace Pilot reward by getting the most air kills in a round
Stingray – Win ten Domination matches
Strigon – Get five Survivor rewards by staying alive the longest amount of time in a round
Sweeper – Shoot down over 50 enemy players online using an attack helicopter
Viking – Earn 20,000 points
Wardog – Get five Ace Striker rewards by getting the most ground kills in a round
Wildcat – Shoot down over 50 enemy players online