Hypoxia Issues Continue Despite Ongoing Investigation

Despite an ongoing investigation and orders for F22 Raptor pilots to stay close to available emergency landing site, another pilot has been stricken with hypoxia like symptoms. According to the website Wired, the incident occurred last Friday off the coast of Hawaii. The pilot was able to land safely but it marks the 23rd case of an unexplained hypoxic incident since the jet was launched in 2005.The incident was revealed to reports on Tuesday by Senator Mark Warner (D-Virginia). While this latest case is under a 30-day review, Warner says it seems to be indicative of a problem that,  "unfortunately seems to be unending." Warner's interest stems from a June incident when a F22 pilot was forced to land after suffering oxygen issues near Langley Air Force Base in Virginia.

The Raptor has been under close scrutiny since a 2010 crash killed the pilot. In 2011 the entire fleet was grounded for four months but an investigation by manufacturers Boeing and Lockheed Martin was inconclusive. The fleet was then ordered back in the air followed by Defense Secretary Leon Panetta's order that they remain near enough to available landing sites to allow a stricken pilot to make an emergency landing. Panetta also ordered backup oxygen system installed, a process that continues.

Investigators have focused on the aircraft's On-Board Oxygen Generating System (OBOGS). Initially they installed charcoal filters only to remove them when pilots began coughing up black phlegm. The pilot's restrictive high pressure G-suits have been analyzed and suspicions of coolant leaking into the oxygen system have been explored all with no results.

Now the attention is again on the OBOGS which Warner says may be suspect in its design. "One of the things that the Air Force had indicated to us was that they were looking at the fact that the OBOGS, when it was originally designed, may have been designed to older standards of how many liters of oxygen per minute a pilot needed," Warner said. "And that when you actually look at the extremely high workloads these pilots are enduring under high gees, heavy maneuvering type of flight, that it may be that they require more oxygen than the system was originally designed to put out."

Even if true, that would not explain the incidents where ground crew servicing the aircraft experienced similar symptoms.

In May, two Raptor pilots, Capt. Josh Wilson and Maj. Jeremy Gordon blew the whistle on the Raptor's problems on CBS's 60 Minutes. Reports were circulating then of pilots refusing to fly the aircraft saying they feared for their lives. Wilson now faces disciplinary action but has been granted whistle blower protection under federal law.

And the investigation continues.

FMI: www.af.mil