Updated at 2:15 p.m. ET
(CBS/AP) HONOLULU - The Hawaii Air National Guard said Tuesday one of its pilots briefly experienced an oxygen deficit while flying an F-22 stealth fighter last week.
The pilot was heading back to Joint Base Pearl Harbor-Hickam from a routine training sortie when sensors indicated he wasn't getting as much oxygen as he should, said Lt. Col. Charles Anthony, a spokesman for the Hawaii Guard.
The pilot also felt dizzy. He activated the emergency oxygen system until his symptoms abated and the plane's oxygen generating system returned to normal.
The pilot landed safely after Friday's incident, the first time a Hawaii F-22 pilot has experienced hypoxia, or oxygen deprivation, Anthony said.
In May, Defense Secretary Leon Panetta ordered that F-22 flights remain "within proximity of potential landing locations" so that pilots can land quickly in the event they experience an oxygen-deficit problem after CBS' "60 Minutes" aired interviews with F-22 pilots who complained about the oxygen problem.
(Below, watch the full "60 Minutes" report)
Maj. Gen. Charles Lyon, who is managing the Air Force's effort to resolve the mysterious problem, told The Associated Press in an interview last month that it is likely that the pilots' symptoms are caused by previously unknown restrictions on their breathing.
Lyon said the root of the problem may turn out to be linked to two issues:
- Improper functioning of the pilots' pressure, or G-force, vest. Lyon said that, unknown to the pilots, the vest's bladder has been filling with air at times when it should not. That has made it harder for the pilots to breath. In mid-June, the Air Force stopped using the vests and was going to modify them before returning them to use in the F-22, Lyon said. In the meantime the Air Force lowered the maximum altitude the F-22 will fly, since the vests are intended to protect pilots' lungs in the event of a sudden loss of cockpit air pressure at high altitudes.
- The hose and hose connectors that are part of the pilot's oxygen delivery system have been leaking slightly, further restricting the amount of oxygen getting to the pilot's lungs.
A medical exam cleared the Hawaii pilot for duty. All 14 of the Hawaii National Guard's F-22 planes are operational, Anthony said.
The F-22 is the Air Force's most-prized stealth fighter. It was built to evade radar and is capable of flying at faster-than-sound speeds without using afterburners.
Five other bases are home to F-22s: Joint Base Elmendorf-Richardson, Alaska; Joint Base Langley-Eustis, Va.; Nellis Air Force Base, Nev.; Holloman Air Force Base, N.M.; and Tyndall Air Force Base, Fla.