Fossett searchers coming up empty

MINDEN, Nevada (CNN) -- Flight teams are following up on leads but have found "nothing promising" in their fourth full day of hunting for billionaire adventurer Steve Fossett, a sheriff's official said Friday.

"Everyone here is hopeful," said Joe Sanford, undersheriff of Lyon County, Nevada, "but I've got to tell you that the family is subdued and they're having a tough time with this. Searchers so far have been frustrated.

"... Mr. Fossett is an accomplished pilot, and no one knows what happened or where he is," Sanford said at a news briefing.

The search now involves about 26 aircraft, including OH-58 Kiowa and UH-60 Black Hawk helicopters from the Nevada National Guard, said Guard Capt. April Conway. A C-130 from the Nevada National Guard that has thermal imaging equipment flew all night without results.

The Civil Air Patrol's Maj. Cynthia Ryan said 650 man-hours had been invested so far in searching an area that has grown to 17,000 square miles in Nevada and California.

Thursday night, Ryan had told reporters authorities had "four credible leads" in the search for Fossett. They apparently did not pan out.

"It's like if you took a 500-piece puzzle, threw four pieces out on the floor randomly and tried to make sense of them. It's a little hard to do," Ryan said Friday.

The search area stretches generally from Yerington, Nevada, close to where Fossett took off Monday morning, west to Lake Tahoe at the Nevada-California state line and south to Bishop, California. The land has been divided into 8.6-square-mile grids so nothing is missed. See a map of search zone »

Ryan flew in a plane piloted by CNN's Miles O'Brien on Wednesday and pointed to the steep canyons, rugged mountains and desert below.

She said the area is dotted with plane wreckage no one has yet removed, and abandoned cars and household goods. She called it "a junkyard."

Although the search is using high-tech means such as a spy satellite, searching the ground below for signs of Fossett's Bellanca Super Decathlon is simple: The pilot and co-pilot scan the terrain from their windows. Watch Ryan show how an air search is done »

"You can only truly see what amounts to the size of your fist as it goes by so you work your eyes along as we go by -- a fist at a time. And you have to let your eyes actually stop moving so that they have time to focus and register what you're actually seeing. After four hours of this, you're beat," Ryan said.

Most crash sites are about 30 yards wide, "and you can very easily miss them."

Ryan and the other searchers remain optimistic Fossett might be alive.

"He apparently didn't have any emergency supplies with him ... but his chances, if he wasn't severely injured, are quite good," she said. "We really think we can find him alive unless something really unfortunate happened."

Fossett took off at 9 a.m. Monday for what was to be a three-hour flight in the single-engine plane, with tail number N240R. Officials said it had four or five hours of fuel. He was searching for possible test sites for an attempt to break the world land-speed record.

He flew from the private air field on hotel magnate Barron Hilton's Flying M Ranch, 30 miles south of Yerington. The aircraft, with serial number 635-80, is registered to the Flying M Hunting Club Inc. in that city.

In 2006, Fossett broke the world's flight distance record by flying 26,000 miles in a single-engine, turbofan aircraft, making the trip in just over three days. He flew for 76 hours, 45 minutes from Cape Canaveral, Florida, to Bournemouth on the coast of southern England, where he was forced to land after the plane's electricity failed. He surpassed the record when he was over Shannon, Ireland. See Steve Fossett's record-setting achievements »

Fossett also was the first person to solo around the world in a balloon, and has broken numerous other flight, ballooning and sailing records.

Sir Richard Branson's Virgin Atlantic sponsored the GlobalFlyer that Fossett flew during the first nonstop, solo flight around the world without refueling in 2005.

On Wednesday Branson said he worried that rescuers had found no sign of his friend but expressed optimism that Fossett, whom he calls "a tough old boot," will surface soon.

"If he's landed and he's not too badly hurt, he's the one person in the world who will be mentally and physically equipped to get out of it," Branson said.

Fossett holds world records in airplane flight (14), ballooning (two), sailing (11), glider flight (six), airship flight (one) and cross-country skiing (one). He's set numerous others that have since been broken by other adventurers. E-mail to a friend

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