The U.S. Air Force has reinstated its entire fleet of F-22 Raptors across the nation.

That means Hawaii's newest fighter jets will be back in the sky.

With the Hawaii Air National Guard being the state's first line of defense, it's important for it to use its state-of-the-art stealth fighters.

Last May, the U.S. Air Force grounded its entire fleet of F-22 Raptors for safety precautions, after pilots complained of not getting enough oxygen while flying.

The grounding included the state's new inventory of fighter jets that replaced the Air National Guard's aging F-15 fighters.

But with the F-15s gone and the new Raptors grounded, Hawaii skies were not left unprotected. F-15s were flown in from Montana to patrol the skies and remain on alert.

The Air Force studied the F-22 for months, and officials announced this week that the analysis of data collected prompted the return to service. But the Air Force did not explain why it considers the planes safe to fly now. The planes and pilots will be subjected to more inspections and testing.

The Air Force has 170 Raptors, including nine in Hawaii. The Air National Guard plans to add an additional 11 F-22s to its fleet.