By Sandra Basu
WASHINGTON — Pilots will be able to breathe easier as a result of changes to the oxygen systems in the F-22 aircraft, Air Force officials recently assured a House committee. The F-22 fleet has been under intense scrutiny after some pilots flying the aircraft mysteriously experienced an unexplained loss of oxygen, causing hypoxia-like symptoms.
Upcoming fixes include the development of a modified Combat Edge upper pressure garment valve that will help “ensure adequate oxygen flow to the pilot.” In addition, an automatic backup oxygen system will be added that “will provide additional protection to F-22 pilots” while flying at a high altitude, according to Maj. Gen. Charles Lyon, director of operations for the Air Combat Command.
“The measures taken by the Air Force, in my opinion, will reduce the [physiological] incident rate significantly and, over time, bring the F-22 incident rates in line with comparable high-performance fighter aircraft,” Lyon said at the congressional hearing.
In written testimony, he further explained that “medical professionals will continue to study the 21st century high-altitude/high-G flight environment and will continue to work with engineers, acquisition officers and the test community to develop enhancements to aircrew flight equipment and oxygen delivery systems.”
Valve Inflates Too Early
In August, the Air Force announced that an internal investigation found that the breathing issues occurred because the valve on the Combat Edge upper pressure garment worn by pilots inflated too early, potentially causing hyperventilation. The Air Force had already removed the upper pressure garments from F-22s in June.
The investigation’s conclusions came after a series of incidents that had shaken confidence in the safety of the F-22s. Beginning in 2008, the F-22 aircraft began to experience a significantly higher rate of hypoxia-like incidents with unknown causes, and concern was heightened in November 2010 after Capt. Jeff Haney died during a training mission at Joint Base Elmendorf-Richardson near Anchorage, Alaska, while flying an F-22.
In May 2011, the Air Force made the decision to stand down the fleet while investigating the problem. It resumed flying status five months later after implementing recommendations to improve safety such as modifying pilots’ life-support equipment and instructing them to immediately end the mission and return at the first sign of any physiological event.
This past spring, the topic got even more public exposure when two Air Force pilots spoke to CBS’ 60 Minutes without military permission about the breathing problems they encountered when flying the F-22.
In May, Secretary of Defense Leon Panetta briefly placed limitations on the Air Force F-22 flights and announced that installation of an automatic backup oxygen system in all F-22 fighters would be expedited.
At a press conference in August announcing results of the investigation, Lyon said, “We combined the medical disciplines of flight medicine, toxicology, physiology, human factors and occupational health with our operators, engineers, logisticians and maintainers to reach our determination.”
He told the House committee this fall that there have been no unexplained physiological incidents among F-22 pilots since March and insisted that “the F-22 cockpit and surrounding work space is a safe, effective place to operate.”
Questions About Pilot Safety
Members of the committee still had questions about pilot safety, however. Rep. Silvestre Reyes (D-TX) asked if pilots with symptoms in danger of any long-term health effects from flying the F-22s.
Air Force Gen. Gregory Martin (ret.), who led an Air Force study on the problem, said there are no indications these pilots will suffer from long-term effects, but his group recommended that the Air Force develop an F-22 pilots’ medical registry, which the Air Force will establish.
Lyon also tried to reassure the committee that some symptoms, such as the so-called Raptor cough experienced by some F-22 pilots, clears up within minutes or hours after flying.
“We have had a small number of pilots who have had incidents that have had lingering effects that have gone out to 48 to 72 hours, but, within 72 hours with treatment by our aerospace medical professionals, those effects go away,” he said. “All of our pilots, all of our ground crew who have had incidents — physiological incidents — have been returned to duty and have been fit for flight duty.”
Not everyone at the hearing was convinced that the Air Force had fully determined what is causing the physiological incidents. Rep. Jackie Speier (D-CA) told Air Force officials without elaborating that she was “deeply concerned” and did not have confidence that they had “come up with the answer yet.”
Speier also pointed to media reports that have accused the Air Force of knowing that problems existed but declining to implement a suggested fix to the oxygen system in 2005.
Lyon said changes were made but acknowledged that the Air Force did not implement a specific recommendation to the oxygen system made in a 2005 report. Lyon said fewer pilots flew F-22s then and not as much was known about the symptoms. “The term ‘Raptor cough’ did not even exist at that time,” he noted.
As more F-22s have been flown, the Air Force has “gained a bigger understanding of what is going on” and is looking at making broader changes to address the F-22s oxygen system, he said.