Well, the F-22 Raptors out of Langley AFB in Virginia and Elmendorf AFB, Ak., are flying again following a short grounding due to concerns about the jet's on-board oxygen systems.
The Viriginia-based Raptors were grounded by 1st Fighter Wing Commander, Col. Kevin Robins, on Oct. 20 after one of his Raptor pilots experienced hypoxia-like symptoms while flying. Emendorf's Raptors were grounded as a cautionary measure, too.
Remember, concerns about problems with the jet's oxygen system causing hypoxia caused the Air Force to ground all F-22s from May until September of this year. (The jets had been flying with altitude restrictions because of the problem for months before that.)
F-22s were only cleared to fly again in September -- special filters have been added to the planes' oxygen systems and pilots are subject to screening and monitoring for any health issues.
The most troubling part of all this is the fact that the Air Force still doesn't know what's behind the reports of possible toxins seeping into pilots' oxygen supplies on its most advanced jet.
Here's what the Air Force told Defense News:
"There is no conclusive cause or group of causes that has been established for the incidents that prompted the standdown earlier this year," Air Combat Command spokesman Scott Knuteson said in an emailed statement. "We've therefore made the decision to resume operations while implementing improvements to the aircraft's life support systems and carefully collecting and analyzing operational, maintenance and physiological data for all Raptor flights - more than 1,300 missions since the return to flight."
However, as a condition to allowing flights to resume, Air Force leaders have enabled operational commanders to suspend operations as needed.
"Part of our protocol is to allow units to pause operations whenever they need to analyze information collected from flight operations to ensure safety," Knuteson said. "That is what is happening at Langley at the moment, and we support that decision."