The US Air Force’s top civilian leader has called for a quick-look study on safety concerns about oxygen generation systems across the combat aircraft fleet.
Secretary of the Air Force Michael Donley directed the Air Force Scientific Advisory Board to conduct the study more than two months into a fleet-wide stand-down for the Lockheed Martin F-22 over related concerns.
The study will focus on oxygen pressurisation systems, oxygen masks and cockpit oxygen levels, according to a USAF press release.
An advisory board team led by retired Gen Gregory Martin will also gather and evaluate information on the oxygen generation systems on a wide variety of combat aircraft, including the F-22, Boeing B-1 and F-15, Fairchild-Republic A-10, Lockheed F-35 and Northrop Grumman B-2. Others include the Bell Boeing CV-22 tiltrotor and the Hawker Beechcraft T-6 trainer, the USAF said.
Flight operations will continue as normal for all USAF aircraft except its F-22s, which remain mostly parked with few exceptions.
Air Combat Command ordered the F-22 stand-down on 3 May after collecting data on several incidents of suspected hypoxia among F-22 pilots. In January, it had limited F-22 operations to below 20,000ft (6,100m). That order came less than two months after an F-22 crashed in Alaska, an incident that remains under investigation.
The focus of the Martin board’s study on subsystems appears to absolve the Honeywell onboard oxygen generation system, which was the initial focus of concerns about the cause of the F-22 stand-down.
Onboard oxygen generation systems have steadily replaced liquid-oxygen during the past three decades on combat aircraft. The systems filter bleed air through a molecular sieve to deliver a regulated supply of oxygen to the pilot, especially at high altitudes.