The service branch imposed a flight ceiling of 25,000 feet in June in response to five incidents of hypoxia-like symptoms or oxygen deprivation experienced by F-35A pilots at Luke AFB.
“We have learned a lot over the past two months and while we have yet to identify a singular cause we have reduced potential causes for labored breathing, carbon monoxide ingestion, and refined our procedures and training,” Brig. Gen. Brook Leonard, 56th fighter wing commander at Luke, said in a statement.
“We will continue to closely monitor operations and work with the joint program office and the human performance wing on future improvements as we move forward building the future of airpower,” he added.
Military.com also reported the service branch has not yet identified the root cause of physiological incidents that occurred from May 2 through June 8.
Officials said the Air Force will begin the testing phase on the On-Board Oxygen Generating System aboard the affected aircraft to facilitate data analysis, the report added.