Air Force pilots cite oxygen problems
Physiological episodes while flying T-6A aircraft unexplained
Pilots flying one of the Air Force’s principal training planes, the troubled T-6A Texan II, have reported 39 unexplained physiological episodes caused by a lack of oxygen since the fleet resumed operations early this year.
The number of incidents, averaging nearly eight a month from the end of February through June, is higher than the average last year, when the most reported in a single month was five.
The planes were briefly grounded after an exceptionally high number of incidents — 22 — were reported in January alone.
The Air Force training command in San Antonio said the T-6A, a single engine, two-seat turboprop craft, is safe to fly. The command said it has done more inspections, bought new testing equipment and increased the frequency of maintenance.
Pilots are getting extra training, learning more about physiological episodes and being armed with new procedures to help them respond to possible oxygen system malfunctions, the command said.
A chief complaint by T-6A instructor pilots is that even after months of investigation, the military still hasn’t found the root cause of problems with the On-
board Oxygen Generation System, called OBOGS. They say many pilots wonder if the plane is safe.
“When I explained it to my wife, it was all the wrong reasons,” said an instructor pilot who asked not to be identified, fearing retribution from commanders. “I’m fearful for second lieutenants that are flying a bad piece of machinery. I’m fearful for how this could be detrimental to my career with the airlines, and my wife is like, ‘You should be afraid for your life. You should be afraid that you’re going to crash an airplane and you’re going to die.’ ”
The oxygen delivery system also is used in a number of fighter jets and in a Navy training plane called the T-45 Goshawk. A raft of changes to bolster confidence in the Goshawk reduced physiological episodes to nine last year.
Cmdr. Scot Cregan, a spokesman for the Navy’s Physiological Episodes Action Team, said eight of the those nine incidents were classified as “minor,” with the other listed as “moderate low.” None of the episodes hindered the ability of aviators to land the aircraft safely, he said. Four of the nine occurred at Naval Air Station Kingsville.
The T-6A first flew at Joint Base San AntonioRandolph in 2000 and had enjoyed one of the lowest occurrences of physiological incidents over the past 10 years.
But a Randolph aviator suffered a physiological episode early this year so serious that a number of pilots there refused to fly. Their chief concern was hypoxia, a lack of oxygen that is potentially fatal with symptoms ranging from fear, anxiety and giddiness to complacency and loss of consciousness.
Hypoxia was suspected when a T-45 from Naval Air Station Kingsville went down Aug. 14, 2016, prompting an instructor pilot and student to bail out.
Pilots concerned about the military’s inability to fully understand OBOGS failures told the San Antonio Express-News that up to 11 aviators at Randolph’s 12th Flying Training Wing had refused early this summer to fly the aerobatic prop plane.
One strategy to combat the problem is to fly without the oxygen system, letting pilots breathe ambient cockpit air while flying modified missions at lower altitudes.
At Randolph, instructor pilots cannot fly the T-6A alone. Novices, however, have to fly solo as part of their training, a requirement that worries some instructors.
“It’s almost unthinkable that the most experienced guys are restricted from flying, but yet the junior, most novice dude can go up and fly it alone in a bad aircraft that we know makes people sick,” one of the Randolph instructor pilots said.
Unexplained mysteries
Developed for fighters in the early 1980s, OBOGS draws outside air from a plane’s engine. The air is cooled and passes through a device called a molecular sieve concentrator that uses a chemical process to produce concentrated oxygen.
A Congressional Research Service brief said OBOGS delivers 95 percent oxygen and 5 percent argon to pilots. The Navy says the air is cleaner than that in a typical office.
One of the mysteries in the OBOGS failures in two-seat training planes is that in some cases only one pilot has suffered an episode, even though OBOGS feeds the same air to both of them.
But some things are known. The Air Force confirmed that inspections have continued to show that the OBOGS shutoff valve, which funnels air from the engine into the system, failed at a rate much higher than anticipated.
The Air Force said the inspections showed that 85 percent of the shutoff valves inspected failed in the open position, allowing unrestricted air flow.
The Air Force is looking into new technology to help pilots monitor their life-support systems in hopes of preventing hypoxia and other physiological episodes. A feasibility study evaluating the inclusion of an automatic backup oxygen system in the T-6A will be completed this month.
In the meantime, 98 percent of the 444 T-6As are back in the air. All of the Navy’s Goshawks are flying.
No punitive action
Lt. Col. J.C. Gorman, who had just taken command of the 559th Flying Training squadron, said he canceled all of the T-6A missions on June 25 after meeting that morning with his pilots. Gorman said that some who had ruled out flying changed their minds after talking it over. The squadron returned to a regular schedule the following day, logging 40 to 45 sorties.
Gorman said pilots always have the option not to fly and that he wouldn’t take punitive action against those who decided not to, explaining, “I don’t need guys being afraid or unconfident in the airplane. In my mind, it’s my responsibility to address their concerns, and that’s what we did and what we continue to do.”
The unusual action came a few days after an instructor was incapacitated on June 21 by a physiological episode while flying the T-6. He was reported to have forgotten which was the lead aircraft in a formation and also had trouble remembering parts of the sortie the next day. Some officers in the squadron said the sickened pilot credited his student with landing the plane and saving his life.
The student was a qualified aviator learning to become a T-6A instructor pilot — not a novice.
“So the (instructor pilot) asked the student, ‘Where is lead?’ The student said, ‘Sir, we’re lead,’ ” one of instructor pilots said.
“He didn’t know where lead was,” another instructor pilot said, adding, “He had lost coherency to anything and everything at that point in time.”
Flying after an episode
Maj. Kinsley Jordan, a T-6A instructor at Vance AFB in Oklahoma, said he suffered a physiological episode during a routine student sortie.
Flying at an altitude of about 1,800 feet, an area typically buzzing with air traffic, Jordan noticed he was thinking sluggishly and was slow to track information from his instruments. Then came a strange, metallic taste in his mouth.
“That’s what really led me to talk with my student, saying, ‘Hey, are you feeling anything? Are you feeling OK?’ The student said, ‘Yeah, I’m feeling fine,’ ” recalled Jordan, who has 3,000 hours in the air, 1,500 of them in combat. “So as we were going through the final turn, that’s when I realized, something’s not right, something’s not right about this.”
He dropped his mask to get a breath of fresh air in the cockpit. The student, whom Jordan described as a slightly above-average novice with 25 hours in a T-6A, showed no symptoms and handled a touchand-go landing on his own.
They then declared an emergency and returned for a second landing, which Jordan made himself.
Jordan said the episode concerned him but not enough that he would refuse to fly the plane.
“It wasn’t necessarily a concern in the sense of ‘Oh, my gosh, I’m not going to go back into the air.’ It was a concern of, ‘I wonder what caused that?’ ” he said. “So it wasn’t anything that I went home and curled up in a ball and sat in my wife’s arms and said, ‘I never want to go back.’ That was not the case.”