Fears for the missing adventurer Steve Fossett are growing tonight as rescuers continue to search in vain for his small plane that disappeared over mountainous desert on Monday.

His wife, Peggy, and his friends and relatives, were pinning their hopes on the grit and experience of the record-breaking aviator, the first man to circumnavigate the globe in a balloon.

Fossett, 63, took off from a private Nevada airstrip just after 9am on Monday in a single-engine plane with four hours’ fuel. He did not file a flight plan and was not wearing a parachute for his short scouting mission to find a dry lake bed for a future attempt on the land speed record.

The aerial rescue mission continued at first light today, with 14 aircraft from Nevada, Utah and California. They conducted grid searches over 7,500sq miles in southwest Nevada, terrain marked by rugged mountains, steep canyons and desert covered in sagebrush.

Unlike Tuesday, when searchers were buffeted by high winds that prevented them from flying close to the mountains, today was calm and clear. The aircraft were able to move close to the ground and the mountainsides. One of the additional search aircraft from Utah was equipped with a spectral imaging system that can differentiate a potential target from background clutter.

Fossett’s aircraft was equipped with food, water and a survival kit. Major Cynthia Ryan, of the Nevada Civil Air Patrol, said: “He’s a very savvy and methodical and determined pilot. I’d give him the highest odds.”

The Bellanca Citabria Super Decathlon aircraft also carried a locator that sends a satellite signal after a rough landing. No signal has been received.

Sir Richard Branson, a friend who sponsored Fossett’s 2005 aviation record — the first solo flight around the world without refuelling — said: “Obviously we’re worried by the fact that there’s been no emergency beacon going off.” He added: “He could be injured, which means the emergency services have just got to get to him as soon as possible.”

Weather conditions on Tuesday pointed to the potential dangers that Fossett might have flown into. One search pilot said the turbulence was so bad that his aircraft dropped 1,500ft in about three seconds. He said the downdrafts and gusts could push aircraft into the granite mountainsides without warning.

Fossett earned his fortune as a financial trader before becoming one of the world’s greatest adventurers. He has set 115 world records, including speed and distance records in balloons, planes, gliders and sailboats. He also swam the English Channel in 1985.

Sir Richard said it would be ironic if Fossett had been killed on such a routine flight after all the dangers he had overcome.

“If you look at the history of adventurers, it is so often the simple things,” he said. “Lawrence of Arabia went through everything and was then killed in a motorbike accident when he’d given up all his dangerous pursuits in Arabia. And that so often happens.”

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