Lockheed Martin remains mum about whether an oxygen system flaw on its F-22 fighter might also plague its sibling, the F-35, but defense analysts say there are reasons to worry.
After a dozen incidents of F-22 pilots losing consciousness mid-flight, Defense Secretary Leon Panetta placed restrictions last week on the Air Force's Raptor fleet amid safety concerns. Panetta has restricted the distances the advanced jets can fly and ordered a fleet-wide installation of an automatic backup oxygen system.
While defense insiders say those restrictions aren't that confining, military experts say similar problems might hit the F-35 fighter, also made by Lockheed.
Richard Aboulafia, a tactical aviation expert at the Teal Group, says "it sounds like there is commonality between them," referring to the F-22 and F-35 fighters.
"This would imply that any lessons learned from testing the F-22 [oxygen] system should be migrated over to the F-35 as quickly as possible," Aboulafia says.
Whether Lockheed Martin and Pentagon officials already are taking such steps is unclear. Lockheed officials did not respond to multiple requests for comment. Defense trade publications have reported the fighters' oxygen systems, made by a subcontractor, are indeed similar, but not carbon copies.
Loren Thompson, a defense analyst at the Lexington Institute and an industry consultant says the F-22 oxygen system flaw likely will not show up across the F-35 fleet.
"The F-35 is not aircraft, but three built for three services and three distinct missions," Thompson says. "That means if there are some carry over issues for the Air Force version of the F-35, it might not carry over to the Navy and Marine variants," he says.
Further, Aboulafia says the super-fast F-22 might be more prone to the oxygen issue than its slower sibling.
"The F-22 system might be more vulnerable to the aircraft's faster speeds and higher altitude capability," Aboulafia says.
The Pentagon's F-22 restrictions, experts say, would not keep it from being deployed if it was needed for a major operation.
For instance, Panetta did not indefinitely ground the entire fleet of 188 F-22 Raptors. He also did not end the deployment of a squadron of F-22s to Al Dhafra Air Base in the United Arab Emirates, near the Iranian border.
Pentagon spokesman Navy Capt. John Kirby said last week the flight-distance restriction is "situational," saying: "I don't believe there's a nautical-mile limit here, it's just about an appropriate level of proximity to [landing] strips."
Despite some chatter in defense circles that the F-22 fleet might be permanently doomed, several longtime military hardware analysts say the Raptor restrictions will likely be lifted soon and the issue will quickly be forgotten.
"The automated system will be installed and this issue should go away in the next two years or so," Thompson says. "But how this path will be traversed, I'm not sure."
John T. Bennett covers national security and foreign policy for U.S. News & World Report. You can contact him at email@example.com or follow him on Twitter.