The commander of Naval Air Systems Command on Tuesday said that the Navy has still not solved the Boeing [BA] T-45C Goshawk pilot breathing system and they have had no student flights with the aircraft since the problem emerged.

Adm. Paul Grosklags told the Senate Armed Services Subcommittee on Seapower that the Navy is not doing well so far on a diagnosis of the T-45C’s onboard oxygen generation system (OBOGS).

He clarified to date almost all of the problems relate to breathing gas as opposed to pressurization issues. They have also been unable to find any toxicants or other contaminants in the breathing gas.

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)

Grosklags said the Navy has tore several of the aircraft apart to test every component in the system from engine to mask. They subjected each component to extreme environmental conditions past what the aircraft experiences but has still not found any contaminants or solved the issue yet.

He said they are now flying several T-45Cs with additional instrumentation to try to detect issues but so far are unable to find the root cause.

For now, the Navy said it is starting to install 10 to 12 alerting and protection measures for the aircrew to detect issues before the aircrew or students are affected by oxygen problems. These measures may allow flights to resume within weeks rather than months, Grosklags said.

He noted Navy instructors are still flying the aircraft, but they are not using the OBOGS system. They are relying on the cockpit air while remaining below 5,000 feet and 2 Gs to remain proficient as flying instructors.

However, Grosklags said this problem is delaying 25 students from moving forward per month, or 75 by the end of this month.

Lt. Gen. Jon Davis, Deputy Commandant for Aviation at the Marine Corps, noted that no physiological episodes have occurred regarding the F-35 B or F-35C after similar incidents occurred with F-35As (Defense Daily, June 13).

“I’ve not heard anything about the C, and nothing on the B right now so we’re not suspending flight ops, we’re watching very carefully.”

Davis noted this OBOGS system in the T-45 is also in the Harrier and “We have no problems in Harriers” so the Navy is still looking for what might be the problem.