The U.S. Air Force temporarily grounded more than two dozen A-10 Warthogs at an Arizona Air Force base late last year after multiple pilots reported hypoxia-like symptoms in flight, Aviation Week has learned.
Two pilots experienced physiological episodes (PEs) during flights out of Davis-Monthan AFB, Arizona, the week of Nov. 27, Air Force spokesman Capt. Josh Benedetti said Jan. 8. In both cases the backup oxygen system kicked in and the pilots landed safely, he said.
One of the aircraft was outfitted with the older liquid oxygen system (LOX) that equips the majority of A-10s, while the other was equipped with the Onboard Oxygen Generation System (Obogs) that is installed on the rest of the fleet, Benedetti said.
A third pilot experienced a problem with the Obogs while he was still on the ground, he noted.
Investigators quickly determined the LOX-equipped aircraft had a cabin pressure and oxygen regulator issue with the LOX system, and fixed the problem. But investigators could not immediately determine the root cause of the problem on the Obogs-equipped aircraft. (end of excerpt)
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