WASHINGTON (CNN) -- Flight restrictions for the plagued F-22 will start to be lifted after the Air Force said it had a plan to mitigate the oxygen issues that sparked questions about the jet fighter's safety.
Defense Secretary Leon Panetta approved the plan to begin lifting the restrictions after the Air Force reported it has identified the issues causing reduced oxygen problems that pilots were experiencing in the cockpit, Pentagon spokesman George Little said Tuesday.
Little said a valve in a pressure vest worn by the pilots to combat the effects of G-forces will have to be replaced, while pilots will receive an increased volume of air flowing to their masks by removing a filter that was installed to determine whether there were any contaminants present in the oxygen system.
But while oxygen contamination was ruled out, the Air Force is also looking at improving the oxygen delivery hose and related connections, according to Little.
In May, Panetta put a series of flight restrictions on the fleet of the world's most advanced and expensive fighter aircraft while the Air Force focused on the problem the plane has been suffering since 2010.
Panetta's order required that F-22 flights stay within range of landing areas the plane could use if pilots experienced an emergency with their oxygen systems.
Little also said Panetta ordered the deployment of a squadron of F-22s to Kadena Air Base in Japan, though those aircraft will be flying under reduced altitudes en route to the base. The Air Force will then look at starting longer-range flights for the rest of the fleet.