Nevada ? With winter closing in, efforts to find aviator Steve Fossett have dwindled – along with hopes that his proven ability to cheat death enabled him to survive a plane crash in the rugged desert of northern Nevada.

More than a month after he left for a short flight, no one has found any trace of him, and authorities have suspended the search, although some private efforts financed by Fossett’s friends and family continue.

“My gut feeling is that he didn’t survive the impact. It’s so unlikely,” said Maj. Cynthia Ryan of the Nevada Civil Air Patrol. She said if Fossett were alive but too injured to walk, he would have tried to signal searchers in some manner.

“He’s not the kind of guy to just sit and wait for help to show up,” Ryan added.

Lyon County Sheriff Allen Veil said Fossett’s disappearance remains under investigation as a missing-person case, and authorities are not prepared to presume the aviator is dead.

“We will try to come to a conclusion, but we’re not there yet,” Veil said.

Fossett, 63, had previously survived a nearly 30,000-foot plunge in a crippled balloon, a dangerous swim through the frigid English Channel and hours stranded in shark-infested seas.