Strong downdrafts that overpowered the climbing ability of Steve Fossett's airplane most likely caused the wealthy adventurer to crash in mountainous terrain west of Mammoth Lakes almost two years ago, federal accident investigators announced.
Fossett, 63, a record-setting balloonist and pilot, disappeared Sept. 3, 2007, after taking off for a pleasure flight from a ranch in Yerington, Nev.
His small single-engine plane failed to return, setting off a massive aerial search that lasted a month and covered 10,000 square miles.
Based on weather and wind conditions on the day of his disappearance, the National Transportation Safety Board concluded that Fossett probably encountered moderate turbulence with gusts up to 35 mph and downdrafts of at least 400 feet per minute, which forced him into the mountains, Los Angeles Times reports.
According to radar evidence, Fossett had begun flying at about 14,500 feet but then radar contact cut out. In addition to the overwhelming downdrafts, officials said that the high altitude of the terrain - the crash happened at an elevation of about 10,000 feet - combined with weather patterns to make the air less dense, thus reducing lift from the wings.
The winds of the Sierra are notoriously dangerous. Within days of his disappearance experts were speculating that he might have fallen victim to them, Guardian News informs .