MINDEN, Nev. -- Rescuers said Wednesday they hoped millionaire adventurer Steve Fossett's nerves of steel will help him as they searched 600 square miles of rawboned Nevada wilderness for his missing plane.

Welcoming calm, cloudy skies, a spokesman for the rescue effort said crews from the Nevada Air National Guard, Civil Air Patrol and Fallon Naval Air Station were back in the air under much better conditions than those brought about by Tuesday's high winds.

But without a flight plan from which to work -- Fossett didn't file one -- the search covers a vast area of desert mountains.

"He was going to make a short flight, near the area of the ranch, take a look at a couple of things and come back," Civil Air Patrol Maj. Cynthia Ryan said at a news conference. "He wasn't planning any expedition or adventure at this point, so it's not uncommon for pilots to not file a flight plan under those circumstances."

Fossett's plane, a Bellanca Citabria Super Decathlon, carried a locator that sends a satellite signal after a rough landing, but officials said they had picked up no locator signals from the plane or radio communication.

Fossett took off alone Monday morning from an airstrip about 70 miles southeast of Reno, Nev. A friend reported him missing when he didn't return at a scheduled time.

Sir Richard Branson, the British billionaire who has helped finance many of Fossett's adventures, said the 63-year-old millionaire was searching for places for an upcoming attempt to break the land speed record in a car.

"This man has a wonderful history of being able to walk out on his own; he's done it more than once," Ryan said of Fossett. "Boy, I'll tell you, if anyone has to be lost out there, this guy has the skills to survive."

Fossett's Records

In 2002, Fossett became the first person to fly around the world alone in a balloon, after five previous attempts.

In March 2005, he became the first person to fly a plane solo around the world without refueling.

He and a co-pilot also claim to have set a world glider altitude record of 50,671 feet during a flight in August 2006 over the Andes Mountains.

Fossett has climbed some of the world's tallest peaks, including the Matterhorn in Switzerland and Mount Kilimanjaro in Tanzania. He also swam the English Channel in 1985, placed 47th in the Iditarod dog sled race in 1992 and participated in the 24 Hours of Le Mans car race in 1996.

In 1995, Fossett became the first person to fly solo across the Pacific Ocean in a balloon, landing in Leader, Saskatchewan, Canada.

He was inducted into the National Aviation Hall of Fame in July.

Fossett and his wife have a home in Beaver Creek, Colo.

About Civil Air Patrol

The Civil Air Patrol, which is playing a key role in the search for Fossett, is an auxiliary of the U.S. Air Force. Its Web site says is has 56,000 members, including 27,000 ages 12-21. The patrol divides its responsibilities into eight geographic regions, with 52 wings and 1,700 units in all. Its headquarters are at Maxwell Air Force Base, Ala. Its 535 single-engine, piston aircraft fleet is the world's largest. It also can call up 1,000 emergency services vehicles, the Web site says.

The organization says it performs 95 percent of nation’s inland search and rescue operations and saves an average of 11 lives every year. It also takes part in disaster relief, reconnaissance for the Department of Homeland Security, transportation of time-sensitive medical materials and assistance in counter-narcotic missions.