The Tactical Air and Land Subcommittee met today for a hearing on F-22 pilot physiological issues. Chairman Roscoe Bartlett (R-MD) made the following statement available as prepared for delivery:
"The subcommittee meets today to receive testimony on F-22 pilot physiological issues which have resulted in reported hypoxia-like events by F-22 pilots over a period of several years.
"From 2003 to April 2008, there were six F-22 physiological incidents, but between April 2008 and January 2011 that number had doubled to 12. As a result of this, the Air Force's Commander of Air Combat Command restricted the F-22's maximum flight altitude to 25,000 feet and directed a safety investigation board to review the F-22's oxygen system.
"In May 2011, the Secretary of the Air Force directed the scientific advisory board to gather information and make recommendations to address deficiencies in the F-22 life support system.
"From May to September of last year, the F-22 fleet stood down as a result of an upward trend in reports of physiological incidents.
"The scientific advisory board completed its work in January of this year but did not determine a cause of the F-22 pilot physiological problems. However, the board did make findings and recommendations, and concluded that either the supply or the quality of the oxygen is contributing to F-22 pilots' hypoxia-like symptoms.
"Air Combat Command established a Life Support System Task Force which continued to examine both the issues of supply and quality of oxygen in the F-22.
"On April 23, 2012, the National Aeronautics and Space Administration (NASA) accepted a request from Air Combat Command to form an independent investigative team to review Air Combat Command's investigative process, on-going root cause analysis, and the F-22 Life Support System, as a whole, to determine potential vulnerabilities to the pilot.
"On July 24th, the Department of Defense announced that Air Combat Command had determined that the root cause of the F-22 pilot physiological issues is the supply of oxygen delivered to the pilots, not the quality of oxygen delivered to the pilots.
"To correct the supply issue and reduce the incidence of hypoxia-related events, the Air Force is making two changes to the aircraft's cockpit life support system.
"First, the Air Force has increased the volume of air flowing to pilots by removing a filter that was installed as part of the investigation to determine whether there were any contaminants present in the oxygen system.
"Second, the Air Force will replace a valve in the upper pressure garment worn by pilots during high-altitude missions. The upper pressure garment is designed to provide counter pressure to assist pilot breathing and to help counteract the effects of g forces. The garment valve was causing the vest to inflate--and remain partially inflated--under conditions where it was not designed to do so, thereby causing breathing problems for some pilots.
"Oxygen contamination was ruled out as a potential cause.
The Air Force is also exploring ways to improve the oxygen delivery hose and its physical connections.
In the interim, the F-22 is under a temporary altitude limit of 44,000 feet.
"Since the F-22 returned to flying status in September of 2011, there have been 11 hypoxia incidents where the case was initially reported as a cause unknown. The Air Force continues to investigate those cases, and as of late July, less than half of those were still unresolved.
"There have been no "cause unknown" hypoxia incidents in the F-22 since March 8, 2012.
"From fiscal year 2002 to May 2011 the Air Force reports an incidence rate of 13 hypoxia events per 100,000 hours compared to 7.5 in the F-16, 1.8 in the F-15E and 6.6 in the F-18E, F, and G over roughly the same period.
"I know from personal experience as a scientist working these issues before I came to Congress that the Air Force faced a difficult problem in determining the root cause of these F-22 pilot hypoxia-like events because in either the case of insufficient oxygen quantity or poor oxygen quality, the symptoms to the pilot are largely the same. Hypoxia, or lack of oxygen, produces the same symptoms in humans that would result from toxic exposure, or hypocapnia, also known as hyperventilation.
"A significant amount of effort has gone into solving the F-22 physiological issues, but much more needs to be done. Recommendations of the Air Force Scientific Advisory Board's Oxygen Generation Study Group need to be implemented. The Air Force Air Combat Command's Life Support Systems Task Force needs to complete its report and provide its final recommendations. Additionally, NASA's Engineering and Safety Center needs to complete its final report and provide its recommendations. The Committee expects the Air Force to keep Congress up to date on the status of all of these reports and recommendations.
"To address the F-22 physiological issues, we've asked the three key leaders involved with this project to testify today.
Retired Air Force General Gregory S. Martin, chairman of the Air Force Scientific Advisory Board Quicklook Study on Aircraft Oxygen Generation. General Martin, welcome back.
Major General Charles W. Lyon, Director of Operations for the Air Combat Command. General Lyon leads the F-22 Life Support System Task Force.
Finally, Mr. Clinton H. Cragg, Principal Engineer at NASA's Engineering and Safety Center. Mr. Cragg leads NASA's independent investigative team which has reviewed Air Combat Command's F-22 processes and analysis.
"Gentlemen, we thank you all for your service to our Country."