The U.S. Air Force has officially ended the Civil Air Patrol's search for explorer Steve Fossett, more than three weeks after he went missing during a single-engine plane flight, the Civil Air Patrol said.
"We consider it suspended," the patrol's acting national commander, Brig. Gen. Amy S. Courter, told ABCNEWS.com today. "If new leads come in, we would consider additional [action] — whether it's interviewing or flying — to support it."
Fossett disappeared Sept. 4 after failing to return to a private airstrip near Yerington, Nev. In the ensuing weeks, searchers used radar and planes to cover a 20,000-square-mile stretch of the desert surrounding the airstrip.
Fossett's trail grew cold after two weeks of searching, but new evidence released last week by the Air Force, including high-tech radar trails, reignited hope that the aviator might be discovered. The search, which had been scaled back by the Air Force the week before, resumed over the weekend.
No trace of Fossett was found.
Despite the patrol's seemingly fastidious analysis of radar and digital images of the desert area surrounding the airstrip, Courter said that she believes there is a possibility new evidence could come to light.
"The radar data has been looked at many, many times," she said. "Having said that, as you may know there are many people around the world that are also looking at information, that are looking at photography and there are chances they may find leads."
During the search, the Civil Air Patrol flew 629 flights, during which searchers used both the naked eye and digital imaging called ARCHER, Airborne Real-Time Cueing Hyperspectral Enhanced Reconnaissance, to record photos of the terrain below. The images were then brought back to the base and analyzed by computers.
ARCHER detects spectral images of objects that it's searching for, in this case, for example, a plane wing. It can also detect anomalies in the rocky terrain or things that don't belong, Courter said.
In addition to the air patrol, experts from the Federal Aviation Administration, the Air Force, Navy and the National Transportation Safety Board helped with the search.
Throughout the search, experts also looked for Fossett's radar track, a clue that experts believe would have led them to the explorer.
"Tracks often come in broken pieces because the radar sites see an aircraft for a short period and then the track vanishes below radar coverage or behind a mountain," said U.S. Air Force radar analysis expert Lt. Guy Loughridge in a statement. "If Fossett's plane flew below mountains at low altitudes, no amount of analytical effort or technology will detect his radar track. We cannot analyze what is not visible."
According to Courter, the lack of radar tracking (Fossett may have literally flown below the radar), not having an emergency transmitter and the sheer amount of the terrain searched contributed to the difficulty in finding Fossett or his plane.
"It's disappointing for us and we're saddened by the potential loss," Courter said. "We continue to wait for leads and hope that some turn up."