The aircrash that killed entrepreneur Steve Fossett, famed for his daredevil aerial feats, probably was caused by downdrafts that exceeded the ability of his small plane to recover before slamming into a mountainside, federal safety officials said Thursday.

Fossett, 63, disappeared on Sept. 3, 2007, after taking off alone from a Nevada ranch owned by hotel magnate Barron Hilton for what was supposed to be a short pleasure flight. His Bellanca 8KCAB-180, a single-engine, two-seater known as the "Super Decathalon," crashed near Mammoth Lakes, Calif.

An extensive, high-profile search failed to turn up any clues to his fate. A year later, on Oct. 7, 2008, a hiker found some of Fossett's belongings. An aerial search located the wreckage about a half-mile away at an elevation of about 10,000 feet.

On the day of the accident, no emergency radio transmissions were received from Fossett, nor were any emergency locator transmitter signals received, the National Transportation Safety Board said in a report.

However, after the wreckage was discovered, a review of radar data from September 2007 revealed a "track" that ended about a mile northwest of the accident site, the board said.

Fossett, who made a fortune in the Chicago commodities market, gained worldwide fame for setting records in high-tech balloons, gliders, jets and boats. He was the first person to circle the world solo in a balloon.

Within two days of Fossett's disappearance, experienced pilots were speculating that even the master of aerial adventure could have fallen victim to the notorious winds on the Sierra's eastern front that are so powerful and tricky they can swirl an airplane like a leaf and even shear off a wing.

"There's been times when I've been flying in the wind and my blood turns cold," Adam Mayberry, a private pilot and former spokesman for the Reno-Tahoe International Airport, said at the time.

Wind gusts in the area can whip up without warning from any direction, with sudden downdrafts that can drag a plane clear to the ground. Passengers flying even on commercial airliners between Las Vegas and Reno know to keep their seat belts fastened for a ride that is never smooth.

Mark Twain wrote about the "Washoe Zephyr" — named for the Nevada county — in the book "Roughing It."

"But, seriously, a Washoe wind is by no means a trifling matter. It blows flimsy houses down, lifts shingle roofs occasionally, rolls up tin ones like sheet music, now and then blows a stagecoach over and spills the passengers," he wrote.

In 1999, three well-known glider pilots were killed in two separate accidents after taking off from the Minden airport north of Yerington.