The U.S. Navy announced April 24 that it will conduct a “comprehensive review” of recent physiological episodes experienced by T-45C and F/A-18 aircrews.

Vice Chief of Naval Operations Adm. Bill Moran on April 21 tapped Adm. Scott Swift, commander of U.S. Pacific Fleet, to form a review team and lead it. The results are due within 30 days.

A T-45C Goshawk training jet approaches an aircraft carrier. (Photo courtesy of U.S. Navy)
A T-45C Goshawk training jet approaches an aircraft carrier. (Photo courtesy of U.S. Navy)

“It is expected that at the completion of the review, Swift will be able to validate current actions and recommend additional actions, if any, that need to be taken,” the Navy said.

The announcement came less than a week after the Navy on April 18 resumed flying its T-45C Goshawks. The Navy grounded the trainer jet fleet April 5 to address physiological episodes caused by contamination of the aircraft’s onboard oxygen generation system (OBOGS).

With the return to flight, the Navy has placed altitude restrictions on the T-45C so that pilots do not need to use the OBOGS. The limit was originally 10,000 feet but was lowered to 5,000 feet in response to feedback from instructor pilots, according to Naval Air Forces.

The T-45C and all three F/A-18 variants – the F/A-18A-D Hornet, F/A-18E/F Super Hornet and EA-18G Growler – have experienced dramatic increases in physiological episodes in recent years. The Growler, for instance, had almost 91 episodes per 100,000 flight hours in the latest reporting period, up from less than six incidents per 100,000 flight hours a few years ago.

In congressional testimony last month, Navy officials outlined 14 steps they are taking to address the F/A-18 and EA-18G problems. For example, parts in the F/A-18 OBOGS were redesigned to keep carbon monoxide from reaching pilots. In addition, a laboratory is being built to study problems with environmental control systems.

Boeing [BA], the prime contractor for the T-45C and F/A-18, said it continues to work closely with the Navy to help identify and solve the causes of the episodes. Physiological episodes involve a decrease in crew performance and can be caused by several factors during flight, including breathing-air contamination and cabin pressure changes.