by Jackie Bartz Channel 2 News KTUU

11:57 a.m. AKDT, September 20, 2011
ANCHORAGE, Alaska—

The nation's fleet of grounded F-22 Raptor fighter jets is set to resume flying after a four-month stand-down, according to senior U.S. Air Force officials.  

"We now have enough insight from recent studies and investigations that a return to flight is prudent and appropriate," U.S. Air Force Chief of Staff Gen. Norton Schwartz said in a statement released on the Air Force website.

The nation's most advanced fighter jet fleet was grounded May 3, 2011, following 12 reports that pilots experienced hypoxia-like symptoms.  The incidents began in 2008, according to the Air Force.    

In November 2010, Joint Base Elmendorf-Richardson based pilot Capt. Jeffrey Haney died outside Denali National Park when the F-22 he was flying crashed.  The cause of that crash has not been released.   

"We're managing the risks with our aircrews, and we're continuing to study the F-22's oxygen systems and collect data to improve it's performance," Schwartz said.

The Air Force says the planes will undergo inspections and the pilots will receive training on life-support systems.

The stand-down lasted 140 days. F-22 pilots need to fly every 210 days to remain proficient, or risk going through the entire training process again.  

Contact Jackie Bartz at jbartz@ktuu.com