The Air Force is “convinced” there is a root cause to a possible oxygen system malfunction that caused the service to ground its F-22 Raptor fleet last summer, but it doesn’t know what it is, according to service officials.
“I am convinced there is a root cause,” Air Force Maj. Gen. Charles Lyon, director of operations, headquarters Air Combat Command, joint base Langley-Eustis, Va., told reporters yesterday during a Pentagon briefing. Lyon later said, “We haven’t found a root cause, but what I’m committed to is that we will not leave any stone unturned. We will use every discipline available every form of study and discipline out there to get at this problem, and that is what we continue to do.”
When asked if pilots were put under unnecessary risk due to not knowing the root cause of the problem, Lyon responded, “No.”
“Pilots are at risk every time we strap an airplane on,” said Air Force Gen. Noel Jones, director of operational capability requirements, deputy chief of staff for operations, plans and requirements. “We are in full belief that the steps that are in place by Air Combat Command (and) the recommendations that (retired) Gen. (Gregory) Martin’s board came up with have given us a very safe airplane while we work to ultimately determine what the root cause is. This airplane is safe and capable of flying.”
Yesterday’s briefing was held to release findings and suggestions from an Air Force Scientific Advisory Board ordered by Secretary Michael Donley last June on aircraft using On-Board Oxygen Generating Systems (OBOGS). Among the findings: the F-22’s OBOGS, backup oxygen system (BOS) and emergency oxygen system (EOS) were not classified as “safety critical items” and the fighter doesn’t have a mechanism for saving the plane should a pilot become temporarily impaired due to hypoxia-like symptoms or other incapacitating events.
Martin, the former Air Force Materiel Command chief who is now retired, chaired the SAB study.
Two recommendations the SAB made included: improving the ease of activating the EOS and providing positive indication to the pilot of successful activation and integrating pilot oxygen saturation status into a tiered warning capability with consideration for automatic BOS activation.
In May 2011, Air Combat Command leadership directed a fleet-wide stand-down of its 165 F-22s following reports that pilots were suffering hypoxia and compression sickness following training sorties. Hypoxia is inadequate oxygen in the blood supply. The fighters returned to service four months later.
The F-22’s OBOGS had been under investigation since an F-22 crashed in Alaska in November 2010. Until the fleet-wide grounding, flights had been restricted to an altitude of 25,000 feet or below for training missions (Defense Daily, May 9). Senior Air Force officials have since said the OBOGS was not at fault for the accident.
The Air Force’s 165 F-22s, developed by Lockheed Martin [LMT], are based in Virginia, New Mexico, Alaska and Hawaii.