The U.S. Air Force says it is it has identified the cause of potentially deadly oxygen deprivation problems experienced by pilots flying the F-22 Raptor fighter jet for years.
A faulty valve in pressure suits worn by pilots at high altitudes caused more than a dozen pilots since 2008 to experience dizziness, disorientation, and even blackouts, Pentagon spokesperson George Little told reporters today.
"I think we have very high confidence that we've identified the issues," Little said, according to an ABC News account of the news conference, before announcing the suspension of flight restrictions put in place on the $79 billion fleet in May.
"The valve was causing the vest to inflate and remain inflated under conditions where it was not designed to do so, thereby causing breathing problems for some pilots," Little said.
To correct the problem, the Air Force plans to replace the valve on the vest and increase the volume of oxygen flowing to pilots by removing a filter installed to determine whether oxygen contamination was the cause of the hypoxia symptoms.
"There was no oxygen contamination," he said, adding that no unexplained hypoxia symptoms have been recorded since March.
The Air Force ordered pilots to stop wearing the pressure vests in June over suspicions that the vests might have been responsible for the oxygen issues.
A month earlier, Defense Secretary Leon Panetta also ordered pilots of the Lockheed-made jets, which have never flown in combat, to fly at low altitudes and within close range of a landing strip.
Two Raptor pilots told CBS News magazine "60 Minutes" in May about their experiences with oxygen deprivation while flying the jet. The video of that interview is embedded below: