Pilots fear strong winds may have downed Fossett's plane

A squadron of 10 aircraft and helicopters spent a fourth day yesterday searching for the missing millionaire adventurer Steve Fossett, whose small plane disappeared over Nevada's high desert.

The pilots flew under clear skies, the best conditions for trying to spot Fossett's single-engine aircraft.

Fossett disappeared on Monday after taking off from a private airstrip to scout sites for an attempt at a land-speed record in a rocket-propelled car.

National Guard C-130s and helicopters with thermal imaging equipment searched the peaks and sagebrush desert of north-west Nevada on Wednesday but failed to find anything new, Major Cynthia Ryan of Nevada Civil Air Patrol said yesterday.

The search across more than 1,700 square miles (4,400 sq km) has covered only a fraction of the territory that could be hiding the plane. Major Ryan said the total search area was 10,000 square miles and the search could take another week.

Fossett's friends and search leaders remain confident the world-famous adventurer is alive. They point to his experience climbing some of the world's best-known peaks, including the Matterhorn in Switzerland. "If anyone has to be lost out there, this man has the skills to survive," Major Ryan said on Wednesday. "With water, he could live out there for two weeks."

Fossett's plane, a Bellanca Citabria Super Decathlon, carried water and food, but there were troubling signs. The missing plane's locator device had not sent a signal, there had been no communication from the plane's radio, and an emergency wristwatch Fossett wore to signal his location had not been activated. Major Ryan said the terrain could make communication difficult and the emergency devices might not be able to send out a signal properly if Fossett was deep in a canyon.

Some veteran pilots speculated he may have fallen victim to the treacherous Sierra Nevada winds that squeeze through the narrow canyons. "There's been times when I've been flying in the wind and my blood turns cold," said Adam Mayberry, a private pilot and former spokesman for the Reno-Tahoe airport.

On Wednesday, searchers spotted a downed aircraft that they believed was Fossett's but it turned out to be one of dozens of old planes that litter the canyons.

Professor Ray Arvidson, chairman of the Earth and Planetary Sciences Department at Washington University in St Louis, worked at the ground operations centre for three of Fossett's balloon flights. "I'm worried," ProfessorArvidson said, "but this guy is a survivor."