May 10 (Bloomberg) -- A Honeywell Inc. system for providing oxygen to F-22 pilots is being investigated as a possible source for malfunctions that prompted the Air Force to ground its premier fighter jet after reports of five incidents since late April, according to officials.
“The inquiry is not solely focused” on Honeywell’s on-board oxygen generating system, Air Combat Command spokeswoman Captain Jennifer Ferrau said in an e-mail. “However, that is one area investigators will look at.”
Honeywell Aerospace spokesman Bill Reavis said “the company will provide appropriate technical and program support in the evaluation of this matter.”
The Air Combat Command on May 3 temporarily halted flights of the F-22 “until further notice,” according to an e-mailed statement from the command, based at Langley Air Force Base, Virginia. The Air Force has taken delivery of 160 of the stealth F-22 jets.
“The stand-down is a prudent measure following recent reports of potential oxygen system malfunctions” and gives Air Force officials time to investigate the system, the command said. The F-22 Raptor is the U.S. military’s most advanced fighter.
The grounding order was spurred by a five instances since late April of F-22 “physiological-hypoxia-like” events that may be indications of potential malfunctions, the Air Force said.
One incident involved a pilot assigned to the 302nd Fighter Squadron in Alaska who “scraped the underside of the aircraft on trees during a landing approach,” an e-mail to congressional defense committees said. “The pilot does not recall the incident and is being treated for physiological symptoms.”
Prior to the five recent F-22 events, nine incidents were reported between June 2008 and February, the Air Force said.
Those nine incidents trigged a safety board investigation of the Honeywell system. The five additional incidents in quick succession triggered the F-22 grounding, however, Ferrau said.
“We are still in the early stages of investigating the reports” and “working to pinpoint the exact nature of the problem.”
A parallel investigation is reviewing the F-35 Joint Strike Fighter’s oxygen system, also made by Morris Township, New Jersey-based Honeywell, she said. The Pentagon plans to buy more than 2,400 F-35s, made by Lockheed Martin Corp., of Bethesda, Maryland.
‘Very Different’ Systems
The two systems “are very different,” the military’s F-35 spokesman, Joe DellaVedova, said in an e-mail. “The program has leveraged the lessons learned from F-22 development to enhance the F-35 across all subsystems, including oxygen system,” he said. “The F-35 program was immediately made aware of last week’s F-22 incidents,” he said.
“At this time, the program office does not see any commonality in the potential causal factors the F-22 program is investigating,” he said.
Lockheed Martin spokeswoman Laurie Quincy said in an e-mail that the F-22 and F-35 oxygen systems have “unique differences” but “as a precaution the F-35 team is reviewing” the Raptor system “design and performance to gain additional insight to improve the F-35 system if required.”
DellaVedova said F-35 program officials continuously monitor “issues present in other aircraft” while “assessing applicability to our current design.”
‘Monitoring Future Findings’
“The F-35 program has both contractor and government engineers supporting the investigation,” he said. “The F-35 will continue to play an active role monitoring future findings and applying them to the F-35 system as appropriate.”
The estimated cost of the F-22 is about $411 million per jet in inflation-adjusted dollars that amortize research, development, production, maintenance and construction of support facilities. That’s about triple the $139 million-per-plane equivalent estimated cost as the program proceeded into full development in 1991, the U.S. Government Accountability Office said in its latest annual report on weapons systems.
F-22 jets are based in Virginia, New Mexico, California, Florida, Alaska and Hawaii.
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