Blood tests on F-22 Raptor fighter pilots after they reported "hypoxia-like symptoms" during flight have turned up chemicals from oil fumes, burned antifreeze and propane. But if the Air Force believes that might be a cause of pilots' symptoms, it's not saying, reports the Air Force Times. Carbon monoxide also is suspect in the incidents, but it leaves the blood quickly. Many of the troubled flights originated at Joint Base Elmendorf-Richardson.
From the Air Force Times:
"There is a lot of nasty stuff getting pumped into the pilots' bloodstream through what they're breathing from that OBOGS [On-Board Oxygen Generation System]. That's fact," one former F-22 pilot said. "How bad it is, what type it is, exactly how much of it, how long - all these things have not been answered."
The blood tests were performed after each of the 14 incidents in which pilots reported various cognitive dysfunctions and other symptoms of hypoxia. One couldn't remember how to change radio frequencies. Another scraped trees on his final approach to the runway - and later could not recall the incident.
"These guys are getting tested for toxins and they've [gotten] toxins out of their bloodstreams," the source said. "One of the guys was expelling propane."
This source, along with the others, requested anonymity for fear of retribution.
The Raptor fleet was mostly grounded in May, months after Capt. Jeff Haney died in a so far unexplained crash north of Anchorage. The Air Force said it was investigating the F-22s' onboard oxygen supply system.
Sources said that in Haney's last few radio calls before his jet disappeared, he sounded drunk, a classic sign of hypoxia. Haney was known as a prodigiously skilled aviator who was in line to attend the elite Air Force Weapons School.
F-22 Raptor pilots have been training in simulators since May, but they will have to be retrained in the actual jets if the grounding extends beyond 210 days, a former pilot said.
Read more at the Air Force Times.