Viper 5 is a minor character in the Ace Combat series, though he has appeared in AC04 & AC5.
Ace Combat 04Edit
In AC04, he is a pilot for the Independent States Allied Forces. He is addressed many times over the radio and flew with Mobius One many times as well. His flown plane is unknown, because during the course of the game, friendly aircraft will change.
Ace Combat 5Edit
Six years later, in AC5, he was a pilot for the OADF. He is only noticed in mission 16, when someone addresses him as Viper 5. His role in the battle or his piloted plane was unknown as well.