The Hawaii Air National Guard confirmed a local incident in which a problem with the oxygen system in the F-22 Raptor jet was reported.
The Air Force has been investigating possible oxygen problems with the jet related to dizziness, nausea, and other hypoxia-like symptoms. Hypoxia happens when a person's body is deprived of adequate oxygen.
The local incident happened on July 6 on a routine training flight that took off from Joint Base Pearl Harbor - Hickam.
The pilot got an indicator that he had a decrease in oxygen after his routine check of the gear.
The pilot activated backup oxygen until the symptom abated. The oxygen-generating system went back to normal and the pilot landed the jet.
The pilot did not lose consciousness and did not experience hypoxia-like symptoms. The pilot was checked out by medical personnel and was okay.
Mechanics looked at the plane and discovered no problems.
All F-22 jets are equipped with a backup oxygen system. Training flights at Joint Base Pearl Harbor - Hickam are on normal operations.
The issue began in May 2011 when the U.S. Air Force grounded its entire F-22 fleet after pilots complained about not getting enough oxygen during flight.
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.