WASHINGTON (AP) — Federal safety officials say downdrafts probably caused the plane crash that killed entrepreneur Steve Fossett nearly two years ago.

The National Transportation Safety Board said Thursday that Fossett's plane struck mountainous terrain near Mammoth Lakes, Calif., following an encounter with downdrafts. Officials say the downdrafts exceeded the ability of his Bellanca 8KCAB-180 to recover through climbing.

Fossett disappeared in September 2007 after taking off from a Nevada ranch owned by hotel magnate Barron Hilton for what was supposed to be a short pleasure flight.

Fossett 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.