The Navy temporarily grounded its fleet of T-45C Goshawk trainer aircraft, because of potential problems with their On Board Oxygen Generator System (OBOGS). Vice Adm. Mike Shoemaker, Commander of Naval Air Forces, announced that the planes would fly again on April 17 – with some changes in equipment, and a ceiling of 10,000 feet.

Goshawks were scheduled to take to the air again in warm-up flights conducted by instructor pilots, who will be wearing modified masks. As the week of these warm-up flights progressed, instructors would then conduct further such flights with student pilots.

“After briefings and discussions with our aircrew, their training wing leadership, the engineers, and aeromedical experts, we have identified a way forward to resume fight operations safely by limiting the maximum cabin altitude to below 10,000 feet in order to operate without using the OBOGS system,” Shoemaker said.

“We will be able to complete 75 percent of the syllabus flights with the modified masks while we continue the important engineering testing and analysis at Pax River [Naval Air Station Patuxent River, Md.], to identify the root cause of the problem. This will remain our top safety priority until we fully understand all causal factors and have identified a solution that will further reduce the risks to our aircrew,” Shoemaker said.

Finding a permanent solution to the OBOGS issue will be a challenge, Shoemaker said, requiring coordination among the medical and engineering communities.
The decision to ground the T-45 garnered support on Capitol Hill.

“The Navy’s decision … Demonstrates the severity of a deeply troubling problem with this aircraft,” said Rep. Niki Tsongas, D-Mass., ranking member of the House Armed Services tactical air and land subcommittee.

Tsongas cited Navy data that indicated pilots lost the ability to perform to their maximum ability because of oxygen deprivation and pressurization issues, all related to OBOGS – on the T-45 and the Navy’s workhorse, the F/A-18E/F Super Hornet.

“Malfunctions .. may pose a heightened risk to both the aircraft crew and people on the ground near training bases,” Tsongas said. “I agree with the … decision to temporarily ground the T-45 fleet, and expect the Navy to address equal leadership attention to this problem as they have to the F-18’s challenges,” she said.