Sam Wilson, stricken by the grief of loosing his parents, changed from a selfless humanitarian to “Snap” Wilson a self-serving racketeer. While en route for a mob assignment in Rio his plane crashes and he’s captured by the Red Skull. The Skull uses the Cosmic Cube to change Wilson back to the community volunteer he once was. Red Skull wanted to use Sam against Captain America, who was also trapped on the island. Skull figured Sam’s idealism and heroism would appeal to Cap and would take him in as his partner. Then Skull would use Sam against Cap.
Sam Wilson had always had a remarkable talent for handling birds, especially his hunting falcon, Redwing. Red Skull used the Comic Cube to give Redwing and Sam a permanent mental link. With Cap’s assistance and training Wilson assumed the costumed identity of Falcon.
Falcon was solely a rooftop swinger Until the Black Panther provided him with Wakandian technology that enabled him to fly.