The Air Force yesterday blamed a faulty pressurization “schedule” in the F-22 for hypoxia-like symptoms its pilots were suffering.
The faulty pressurization schedule caused a pressurized vest to inflate, restricting proper breathing in pilots, Air Combat Command Director of Operations Air Force Maj. Gen. Charles Lyon told reporters at the Pentagon. The pressurized vest is designed to protect pilots’ lungs in case of rapid decompression.
“What we found is the pressurization schedule of the F-22 inflates this prematurely. So we’ve removed this (and) pilots are not flying with this garment today,” Lyon said. “We took it off in early June while we (did) the testing and made the fix.”
Lyon said a faulty valve connected to the pressurized vest was also to blame for the breathing irregularities.
“What we discovered in the F-22 is that valve is opening under normal conditions in an F-22 when it should not,” Lyon said. “So this vest is always inflated on an F-22 pilot and it should not be inflated until they start to pull (G-forces).”
Lyon said the hypoxia-like symptoms were really the simple inability of pilots to breathe properly. Hypoxia is inadequate oxygen in the blood supply.
“If you hyperventilate, you are no longer doing efficient breathing and one of the first symptoms you get from hyperventilation is a lightheadedness or dizziness,” Lyon said.
Outgoing Air Force Chief of Staff Gen. Norton Schwartz said July 24 the service confirmed a combination of hardware-related items created breathing problems for pilots. Schwartz said the Air Force has a “deliberate plan” underway to modify and test that equipment under the most demanding conditions and the plan will “hit the field” in September (Defense Daily, July 25).
Defense Secretary Leon Panetta is satisfied the Air Force has identified the cause of the F-22’s hypoxia-like symptoms and will gradually lift F-22 flight restrictions enacted in May, Pentagon spokesman George Little said on July 24. The Pentagon last week sent F-22s to Japan via the northern Pacific transit route and restricted the altitude levels of pilots for safety’s sake and had a F-22 pilot follow in an aerial refueling tanker to offer advice.
The F-22 is developed by Lockheed Martin [LMT].