WASHINGTON Defense Secretary Leon Panetta approved plans to send a squadron of Lockheed Martin Corp F-22 fighter jets to Japan, a step toward lifting flight restrictions on the most advanced U.S. warplane after the Air Force ruled out that contaminants were causing some F-22 pilots to get dizzy at the controls.
Pentagon spokesman George Little announced the decision on Tuesday, noting that a detailed and lengthy Air Force analysis had concluded that symptoms of oxygen deprivation experienced by some F-22 pilots were caused by the amount of oxygen delivered to pilots, not the quality of the air.
He said the Air Force was initiating a series of actions aimed at removing current altitude and other restrictions on the F-22 over time, and would recommend resuming most long-duration flights after the F-22 squadron flew to Japan.
The Air Force stopped flying the F-22 completely for five months last year. It resumed flights in September, but in May the Pentagon imposed new restrictions on how far they could fly from airstrips and how high they could climb.
Concern about the aircraft flared again this year after two F-22 pilots told CBS's "60 Minutes" program they had stopped flying the fighter jet due to worries about safety.
Panetta "believes that pilot safety is paramount," Little said. "The gradual lifting of restrictions will enable the Air Force to resume normal F-22 operations over time while ensuring the safety of the incredible airmen who fly this critical aircraft."
Air Force Chief of Staff General Norton Schwartz said the squadron of F-22s traveling to the U.S. air base in Kadena, Japan would be accompanied by a refueling tanker, that would carry an F-22 pilot on board, who "can offer advice" in case any further incidents of oxygen deprivation, or hypoxia, developed en route.
He said the tankers would follow a flight plan that meant they were never more than an hour and a half from a landing point, and the accompanying tanker would carry enough fuel to allow the planes to reach their destination at a lower altitude
"We're confident that we have managed the risk associated with continuing operations in the F-22," Schwartz said, noting that modified equipment would be available in September, and it would be tested under the most demanding conditions.
"What we have is a phased approach to removing limitations," Schwartz said. "We have to go back to the Secretary of Defense and demonstrate the results of the improvements, the tests that we've performed, and get his head nod on each sequential."
He said the risk associated with continued operations would be minimized but not wholly eliminated until the equipment modifications were in place.
Asked why the F-22s were being sent to Japan now, Schwartz said, "There's an operational requirement and the birds are ready to go." He gave no further details.
Little said the Air Force would replace a valve in flight suits that had restricted breathing at high altitude and has increased the oxygen supply to pilots by removing a charcoal air filter aimed at trapping contaminants that was actually making it harder for pilots to breathe.
"After receiving assurances that these corrective measures would minimize hypoxia-like events in the F-22, (Defense Secretary Leon Panetta) approved the Air Force planned sequence of actions to remove flight restrictions over time. This process starts today," Little told reporters.
Senator Mark Warner, a Virginia Democrat, and Representative Adam Kinzinger, an Illinois Republican, said the news was promising, but most safety restrictions should remain in force.
They welcomed news that the Air Force had stopped using the charcoal breathing filters that prompted the two pilots to go public about their concerns, and urged the Air Force to rescind disciplinary actions that were still pending against them.
Air Force officials have said they will afford the pilots the same protections guaranteed to government whistleblowers.
Little said the Air Force would also complete other steps designed to make the planes safer, including installation of a back-up oxygen system.
He said altitude restrictions for F-22s could be lifted as early as the fall after a revamped high-altitude garment had been tested and other improvements and studies completed.
Alison Orne, a spokeswoman for Lockheed, welcomed the news, noting that the Air Force was taking the issue very seriously and doing all it could to ensure the safety of the pilots.
Asked why the issue was not discovered earlier, Schwartz said the F-22 was a unique airplane.
"You can pull G6 Gs at 50,000 feet. Tell me what other airplane ever can do that," he said, referring to the airplane's unique ability to defy gravitational forces and execute hairpin turns at high altitudes.
Schwartz said testing of the airplane did not reveal the shortcomings that were recently discovered, underscoring the need for deep and continuous testing.
(Reporting By Missy Ryan, David Alexander and Andrea Shalal-Esa; Editing by David Brunnstrom and Andrew Hay)