Jim Mitchell always had the ability to fly. He loved it. He could zip down to the corner market in seconds, get across town in minutes, sometimes even save somebody. Mitchell's ability kept getting better and better, allowing him to go faster and pick up more weight. After an almost lethal encounter with a villain, he started carrying an armored shell with weapons built into it.
By the time he had been asked to join the team he had became the Flying Fortress.
CES