Several leads but no results in Fossett search

RENO, Nevada, Sep 8 (Reuters) Air crews searched a 10,000 sq mile (26,000 sq km) area of the Nevada and California desert for a fifth day yesterday but still had no clue on the whereabouts of missing US adventurer Steve Fossett.

Two aircraft equipped with infrared technology flew throughout Thursday night looking for the 63-year-old millionaire and aviation record-setter whose plane disappeared on Monday as he was scouting sites for a planned attempt to set a land speed record.

Authorities told reporters they had followed up several leads and apparent sightings over the past few days but had turned up nothing promising.

Wreckage was spotted in the Black Rock Desert north of Reno on Thursday but it turned out to be a 43-year old crash site.

Maj Cynthia Ryan of the Nevada Civil Air Patrol said 90 per cent of Nevada is restricted military airspace and that radar would detect the slightest incursion into that area.

Authorities are instead focusing their search on a 10,000 sq mile (26,000 sq km) area -- equivalent to the state of Maryland -- outside the military airspace.

Ryan said the suspected crash could remain undetected for months, noting that many previous wrecks have only been discovered by hikers in the barren and mountainous terrain.

''In the spring, when the snow has melted, sometimes they find them then. But we have every intention of working this search until we come to a conclusion where we know what happened and we can come to some sort of closure for family and friends,'' Ryan told reporters.

Authorities on Thursday added ground patrols to the search and sent boats to check out Nevada's Walker Lake in addition to the 12 or more planes searching the terrain.

Some are equipped with imaging technology that quickly distinguishes man-made objects, including aircraft wreckage, from natural objects.

But no sign has been seen of Fossett's small single-engine plane, nor any indication of what might have happened to him.

Searchers said they had been unable to confirm with Fossett's family that the adventurer was wearing a sophisticated watch that is designed to let pilots signal their location in an emergency.

Fossett, who has a record of getting out of tough situations, became the first person to fly a balloon solo around the world in 2002 and made a record-setting solo nonstop airplane flight around the world in 2005.

He also climbed more than 400 mountain peaks, swam the English Channel, raced in the Le Mans auto race and competed in Alaska's Iditarod Trail Sled Dog Race.

REUTERS PBB RN0609