The U.S. Air Force will resume flights of Lockheed Martin Corp.’s F-22 Raptor this week, which has been grounded for four months after pilots suffered symptoms related to oxygen deprivation.
“We now have enough insight from recent studies and investigations that a return to flight is prudent and appropriate,” said Air Force Chief of Staff General Norton Schwartz in a written statement.
“We’re managing the risks with our air crews, and we’re continuing to study the F-22’s oxygen systems and collect data to improve its performance,” he said. Returning to flight Sept. 21, pilots will use additional safety equipment and undergo physiological tests.
The flight ban was imposed on May 3 as a safety precaution after 12 separate incidents in which pilots experienced “hypoxia-like symptoms” associated with lack of oxygen, according to a statement from Air Combat Command. Oxygen deprivation can lead to disorientation or blackouts.
A continuing Air Force investigation found that, under certain conditions, Honeywell International Inc.’s On-Board Oxygen Generating System “does not deliver oxygen as designed to the pilot, which could result in hypoxia and decreased flight safety,” the written notification said.
Even so, it said the probe “failed to reveal a single, definitive root cause for the hypoxia-like symptoms.”
‘More Reliable’ System
Honeywell, based in Morris Township, New Jersey, said on its website that its oxygen system “is more reliable, safer and requires much less maintenance than a comparable stored-gas system.”
Lockheed Martin spokeswoman Alison Orne said the company was pleased with the Air Force decision.“We are committed to supporting our customer in getting the world’s premier air dominance fighter, and the men and women who fly them, safely back in the air,” she said in an e-mailed statement.
Honeywell spokesman Christopher Barker referred questions about the investigation of the oxygen system to the Air Force.
The entire F-22 fleet will undergo “an extensive inspection of the life-support systems before returning to flight,” the Air Combat Command statement said.
The Air Force has fielded 170 F-22 jets as of May. The stealth plane first entered service in 2005.