LOS ANGELES (AFP) — The search for missing adventurer Steve Fossett entered a sixth day on Saturday with searchers still no closer to unraveling the mystery of the millionaire aviator's fate.
A first wave of aircraft took off from Minden Air Base in northwestern Nevada around 8:00 am (1500 GMT).
Later Saturday a total of 45 planes and helicopters, including around a dozen of volunteer pilots in private aircraft, were patrolling the region, rescue officials said.
"Anything reasonable that we can add is probably going to make a difference, but we won't know that until we find our target," Civil Air Patrol Major Cynthia Ryan told reporters on Saturday.
Fossett, the 63-year-old veteran of numerous world record-breaking plane and balloon flights, has not been heard from since Monday, when he failed to return after taking off from a private airstrip 80 miles (130 km) southeast of Reno, Nevada on a solo flight.
Fossett's failure to file a flight plan has left rescuers scouring a vast 10,000 square mile (25,900 kilometer) expanse of rugged mountain and desert wilderness with no firm idea of where the aviator's plane may be.
"We've said it's like looking for a needle in a haystack and that's exactly what it's like," said Nevada State Police spokesman Chuck Allen.
Underscoring the vastness of the area being searched, officials said spotter planes have so far found wreckage from six previously unrecorded crash sites.
Meanwhile, Ryan praised the contribution of volunteer pilots involved in the search. "They did some of their own work based on what Mr Fossett's habits were. They've done an amazing job in the area that they have searched."
Lyon County under sheriff Joe Sanford told reporters on Friday that members of Fossett's family were struggling to maintain their optimism.
"Everyone here is hopeful, but I've got to tell you that they're having a tough time with this," Sanford said.
Fossett has survived numerous near-misses and harrowing crash landings over the years, including a 29,000-foot (9,000-meter) plummet into the Coral Sea off Australia because of a storm-shredded balloon.
Rescuers do not believe Fossett had packed food and water aboard his plane because he had only planned a three-hour flight.
Fossett's single-engine Bellanca aircraft was equipped with an electronic tracking device designed to be triggered in the event of a rough landing, but it has not been activated.
Fossett made the first solo nonstop, non-refueled circumnavigation of the world in 67 hours in the Virgin Atlantic GlobalFlyer. In 2002, he was the first person to fly solo around the world in a balloon.