From above, landscape reveals little in search for aviator Steve Fossett

MINDEN - High above a landscape of canyons and shadows, veteran pilot Jim Herd sees a tiny flash on a mountainside. A mirror? A piece of wreckage?

A closer look reveals a prospector's small mine, the reflection most likely coming from metal fencing or some broken glass.

It was just another false alarm during a week of mysteries and dashed hopes in the search for millionaire adventurer Steve Fossett.

The other-worldly terrain of northwestern Nevada has bedeviled the many search crews who have been hunting around the clock since the 63-year-old aviator disappeared on Monday after setting out in a single-engine plane.

Flying over the mountains, flats, canyons and gullies - a land of tricky shapes and shifting light - it is easy to see how Fossett's plane has eluded them.

"When you stare down at the desert long enough, you'll know it when you see something that doesn't look normal," said Herd, guiding his Beechcraft Bonanza toward a barren ridge, its gentle folds looking like a rumpled blanket from 2,000 feet overhead. "But you can be fooled. Even a broken beer bottle will sparkle when the light is just right."

The skies over the search area - more than 10,000 square miles, or an expanse the size of Massachusetts - have swarmed with aircraft since Fossett was reported missing on a flight to scout out desert locations for his latest adventure, an attempt to set a land-speed record in a jet-propelled car.

On Friday, 26 planes and helicopters took off from the search headquarters at the Minden airport. Most of the planes are small aircraft flown by members of the Nevada, California and Utah Civil Air Patrols and contain a pilot and two spotters.

The continuous scanning of the ground can be monotonous and draining. The crews are bounced by turbulence and strain to see even the smallest detail that might seem out of place in an austere landscape that seems to stretch forever.

"You have to keep from getting real fatigued and losing your concentration out there," said Randy McLain, a Nevada Civil Air Patrol officer.

Despite the absence of clues, searchers remain hopeful, knowing that Fossett has a Houdini-like history of escaping from seemingly impossible jams. He has held 116 speed or distance records on land, air and water, including being the first to circle the globe alone in a balloon.

In the Beechcraft, pilot Herd retraces part of the route Fossett initially took when he set out from hotel magnate Barron Hilton's Flying M ranch about 80 miles southeast of Reno.

Fossett headed south in his single-engine Bellanca Citabria Super Decathlon. He most likely would have threaded 8,000-foot-high Lucky Boy Pass, the safest route in that mountainous section.

Once he cleared the pass, Fossett could have flown in any direction. If he turned east over Walker Lake, where sonar is being used to see if his plane is lying on the bottom, Fossett would have flown around wind-swept Mount Grant, which at 11,245 feet dominates the horizon. The many deep canyons and crevices on its flanks also are being examined.

"There are a lot of ravines that are hard to search ... a lot of nooks and crannies we have to look at," said Nevada Civil Air Patrol Maj. Cynthia Ryan.

Many of the mountains are covered by pinon pines. They are no taller than 15 or 20 feet, but that is enough for a small plane to slide under and become nearly invisible from above.

Nevada Highway Patrol trooper Chuck Allen said Friday authorities believe Fossett had only one bottle of water aboard his small plane. Search officials said earlier in the week that it contained food and enough water to last two weeks.

Earlier this week, searchers became excited when they spotted a plane wreck from the air. But a helicopter crew reached the site and determined it was a plane that went down decades ago.

On Friday, rescue crews were dispatched to another downed plane that was spotted on a hillside about 45 miles southeast of Reno near Fort Churchill State Park. Lyon County Undersheriff Joe Sanford told reporters it was an older crash site and the plane was not Fossett's.

From the air, hope can quickly give way to disappointment.

Is that a patch of scorched earth, or just a band of colored rock? An object that appears promising from a distance turns out to be nothing more than a storage shed.