US Navy lifts Goshawk grounding, though restrictions remain

Gareth Jennings

The US Navy (USN) has lifted the grounding order on its fleet of Boeing T-45 Goshawk jet trainer aircraft, though restrictions remain in place while the service continues to investigate problems with the Onboard Oxygen Generation System (OBOGS).

The suspension of flight operations, which was imposed on 5 April and extended on 10 April, was lifted by Vice Admiral Mike Shoemaker, Commander Naval Air Forces, on 17 April. Certain restrictions, however, remain in place to safeguard crew safety while the cause of the problem remains unknown.

“After briefings and discussions with our aircrew, their training wing leadership, the engineers, and aeromedical experts, we have identified a way forward to resume flight operations safely by limiting the maximum cabin altitude to below 10,000 ft in order to be able to operate without using the OBOGS system,” Adm Shoemaker was quoted by the navy as saying.

As noted by the USN, the ‘way forward’ for the resumption of flight operations in centred on a modified oxygen mask to be worn by the pilots. This mask circumvents the aircraft’s OBOGS system which is believed to be behind a series of physiological episodes that led to the suspension of flight operations.

“Initially, instructor pilots will conduct warm-up flights, after which they will brief the remaining pilots and students in their squadrons on use of the modified equipment. As the week progresses all instructor pilots will complete their warm-up flights, followed by warmups and training flights for student pilots,” the USN said, with Adm Shoemaker adding, “We will be able to complete 75% 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, Maryland] 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.”