“I have fear,” he said. “Without a doubt. It does scare me. Honestly, if it didn’t, it would be time to stop doing it. When you’re nonchalant, then accidents happen. I use the fear and paranoia to allow myself to take control.”

In recent years, a group of roughly half a dozen have had similar ambitions to fly from planes without the aid of a parachute.

Connery, however, was a relative unknown to those practitioners, the more renowned wing-suit diver Jeb Corliss said. Six years ago, Corliss embarked on his own plan to try to fly without the aid of a parachute. He said Wednesday that he was still trying to raise funds. In February, speculation spread among stunt divers about Connery’s attempt.

“We had never heard of this guy,” Corliss said. “We thought it was crazy.”

For weeks, Connery’s plans were plagued by forecasts for inclement weather in Britain, keeping him and sky divers in suspense over whether he would make a serious attempt.

Watching a video of Connery’s flight online Wednesday afternoon, Corliss said he was surprised that Connery approached the cardboard-box runway headfirst, increasing his risk of neck injury, as opposed to with his back. (Connery said he wore a helmet and neck brace for his flight.)