But millions of dollars later, the mystery remains. On the same day Panetta ordered the Air Force to expedite installation of the backup system, he also ordered the Air Force to corral the planes and restrict their missions so they are always near a landing strip, just in case something goes wrong again.
The jets are still on forward deployment, however, and the Air Force claims that neither the mystery problem nor the flight restrictions have curbed F-22 operations. The service has long maintained that while they are aggressively investigating the cause of the apparent oxygen deprivation and have taken a number of measures to ensure pilot safety, the oxygen-related safety incidents themselves are exceedingly rare – 25 known instances compared to the thousands of successful flights flown.
The new automatic backup system is scheduled to begin appearing in planes in December but will not be installed on the entire fleet until 2014, according to the Air Force.