Why Did They Continue to Fly F22 Raptor When It Was Causing Hypoxia
Oxygen Problems on F-22 Elude the Air Force's Fixes
JOINT BASE LANGLEY-EUSTIS, Va. — Capt. Jeff Haney was at 51,000 feet on a night flight above Alaska in November 2010 when the oxygen system in his F-22 Raptor fighter jet shut down, restricting his ability to breathe as he plummeted faster than the speed of sound into the tundra below. His plane burned a crater into the ice, froze 40 feet beneath the surface and was not fully recovered until the spring thaw.
Captain Haney's death unnerved the elite community of F-22 pilots, as did a series of episodes over the next 18 months in which an alarming number of them experienced symptoms of hypoxia, or oxygen deprivation. The Air Force grounded the Raptor, the jewel of its fleet, but could not find anything wrong, so it put the jet back in the air — only to have the episodes increase. In May, two seasoned pilots took the extraordinary step of telling CBS News's "60 Minutes" that they refused to fly the plane.
Last month, a breakthrough seemed to come at last. Investigators believed that a malfunctioning pressure vest was restricting pilots' breathing and that narrow oxygen hoses were leaking and not delivering enough air. Pilots began flying without the vest, and, buoyed by three months without an episode, Air Force officials told the news media that they might be close to a solution.
But last week, as Air Force officials escorted a reporter and a photographer to the Langley flight line to watch F-22s roaring on and off the runway for an ostensible good-news story, it happened again. A pilot pulled his emergency oxygen handle sometime after landing because of what the Air Force characterized as "discomfort" from intermittent air flow into the pilot's mask during flight. The Air Force is investigating but so far has said little.
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Senator Mark Warner, for one, is outraged by the episode. "I've been pressing them about the explanation for this, and we still don't have an answer," he said in an interview on Friday. "We don't even have the full details yet."
Mr. Warner, a Virginia Democrat who has taken up the cause of the two pilots who spoke to "60 Minutes" because they are constituents who fly out of Langley, said he was equally frustrated that the Air Force was only now coming to the conclusion that there might be a problem with the jet's oxygen flow.
"Wouldn't this have been the first question to be asked?" he said.
The F-22, which at $400 million is the world's most expensive fighter jet, was conceived during the cold war when the Air Force wanted a plane to counter improvements in Russian MIGs. But the Soviet Union disappeared long before Lockheed Martin built the first assembly-line version of the F-22 in 1997. By then critics had branded it a relic.
It was not until 2009 that Congress, pushed by President Obama and the defense secretary at the time, Robert M. Gates, agreed to limit the number of planes it would pay for to 187, the number now in service.
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Although the stealthy jet is a technological wonder that can fly higher, faster and with more maneuvers than any other, it has never been used in combat. (A squadron of F-22s is deployed to a base in the Persian Gulf as a deterrent to Iran.) The plane sat out the wars in Iraq and Afghanistan and the conflict in Libya because it was not needed.
"Last I checked, the Taliban air force was pretty small," said Richard L. Aboulafia, an aviation analyst at the Teal Group in Fairfax, Va. But Mr. Aboulafia, who compares the F-22 to a Maserati and the newer and relatively less expensive F-35 Joint Strike Fighter to a BMW sedan, said he supported the F-22 as a hedge against future developments in Chinese aircraft.
The Air Force says that since the plane was put into operation in 2005, pilots have experienced 21 unexplained episodes of hypoxialike symptoms. At least three episodes occurred before Captain Haney's death. (His crash is not included in the 21 episodes because the Air Force counts it as one of 15 additional "explained" hypoxialike events — anything from a loose air hose to a total failure of the life-support system.)
It was not until 10 unexplained episodes had occurred that the Air Force took the drastic step in May 2011 of grounding the entire F-22 fleet. Investigators combed through the planes, focusing on whether there were contaminants in the oxygen system that might be making pilots disoriented. They found nothing conclusive. But as a precaution — and for further testing — the Air Force gave pilots devices to monitor their oxygen levels during flight and installed charcoal filters in the air system to block potential poisons.
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The plane resumed flying in September, but within six months there were 11 more unexplained episodes, and some pilots were coughing up black sputum. Ground crews that worked in the cockpit were also affected. Air Force doctors determined that at the very least the charcoal filter was restricting airflow. It was removed in late April, shortly before the "60 Minutes" episode was shown.
Within days of the broadcast, Defense Secretary Leon E. Panetta ordered the Air Force to keep all F-22 flights within safe proximity of landing strips — or about 30 minutes of flight time from an air base — and to speed up the installation of an automatic backup oxygen system.
By that time the focus of the Air Force had shifted to the quantity, rather than the quality, of the oxygen in the jet. Working with NASA and an elite Navy diving unit, investigators determined in recent weeks that pilot vests meant to inflate as a safeguard against sudden decompression at high altitudes were staying inflated throughout the flights. The result was more pressure on pilots who were already breathing heavily from powerful G-forces in training for aerial combat.
"This is a lot like a corset, except that it's around my chest," said Maj. Gen. Charles Lyon, an Air Force pilot who is leading a new investigation into the jet's problems. In addition, General Lyon said his inquiry had discovered that F-22 pilots were gulping air in physically demanding situations, like practice dogfights, at higher rates than the plane's oxygen system could produce.
By mid-June, the Air Force ordered pilots to fly without the vest but to stay below 44,000 feet to avoid dangers from any high-altitude decompression. The Air Force at the same time began moves to redesign the garment, widen the jet's air hoses and fix any leaks. "Everything is on a positive trend line," General Lyon said.
The general spoke four days before the most recent episode at Langley, which occurred last Tuesday, when the pilot was, as ordered, not wearing a vest. Lt. Col. Tadd Sholtis, an Air Force spokesman, said it was too soon to say what other factors might have caused the episode, although so far it appeared to be a "mechanical problem" with the life-support system.
Source: https://www.nytimes.com/2012/07/03/us/politics/for-f-22-oxygen-problems-elude-air-forces-fixes.html
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