The Pentagon is announcing new precautions aimed at protecting the safety of pilots of some Air Force fighter jets, who have found themselves in potentially deadly situations far from combat.

FOX News Radio's Chris Foster reports in our ongoing series on national security:

Securing America.

Some F-22 fighter pilots experience oxygen deprivation, an issue that grounded the planes for five months last year. Pentagon spokesman George Little says they can't figure out what's causing it, but for now;

(Little) "The Air Force will expedite installation of an automatic backup oxygen system in all F-22 fighters."

They're also limiting the fighter's range.

(Little) "All F-22 flights will remain within the proximity of potential landing locations to enable quick recovery and landing should a pilot encounter unanticipated physiological conditions during flight."

He says there will be regular progress reports, with another grounding if necessary.

Chris Foster, FOX News Radio.