WASHINGTON (AP) - With growing hysteria over alleged UFO sightings in the 1950s, the Air Force repeatedly concocted false cover stories to hide the fact that their super-secret spy planes had been spotted, an intelligence study says.
Historian Gerald K. Haines writes that the Air Force, responding to alleged UFO sightings during the Cold War years, frequently provided explanations that were untrue to deflect attention away from the spy planes.
"Over half of all UFO reports from the late 1950s through the 1960s were accounted for by manned reconnaissance flights (namely the U-2) over the United States," Haines wrote in the spring issue of Studies of Intelligence, an unclassified CIA journal.
The article was found Saturday on the Internet.
Concern about the public finding out about the secret spy planes "led the Air Force to make misleading and deceptive statements to the public in order to allay public fears and to protect an extraordinarily sensitive national security project," Haines wrote.
"While perhaps justified, this deception added fuel to the later conspiracy theories and the coverup controversy..." regarding the existence of UFOs, he added.
Haines, a historian at the National Reconnaissance Office, based his article on a review of CIA documents from the late 1940s to 1990.
He described how the Air Force sought to deflect attention from the development of its high-altitude experimental aircraft, the U-2 and the SR-71.
The early U-2s were silver and reflected the sun's rays, especially at sunrise and sunset, and often appeared as fiery objects to people below, Haines said. The U-2s were later painted black.
Air Force investigators "aware of the secret U-2 flights tried to explain away such sightings by linking them to natural phenomena such as ice crystals and temperature inversions," Haines wrote.
By 1956, the Air Force internally had clear explanations for 96 percent of all UFO sightings, Haines wrote, referring to the experimental aircraft. "They were careful, however, not to reveal the true cause of the sighting to the public."
He also said the CIA, during the height of the Cold War, hid its involvement in studies into UFO sightings because the agency was concerned if word came out it would lead to a national hysteria that could be exploited by the Soviet Union.
The director of space policy at the Washington-based Federation of American Scientists, John E. Pike, said the study raises questions about other possible government coverups involving unidentified flying objects.
"The flying-saucer community is definitely onto something," in accusing the military of hiding something, Pike told The New York Times, which reported on the study in Sunday's edition.
Haines' study, "CIA's Role in the Study of UFOs, 1947-90," is available on the Internet at http://www.odci.gov/csi/studies/97unclas/