Air Force Believes It Has Fix For Hypoxia Issues In T-6 Trainers

The U.S. Air Force is implementing a set of upgrades on its T-6 Texan II trainer fleet to address a spate of unexplained physiological events, including hypoxia, that occurred in early 2018, reports the Air Force Times.

Several T-6 pilots reported the symptoms in November 2017. Training operations were suspended for three weeks before resuming on Dec. 5, 2017. The T-6 fleet was grounded again, this time for a month, in January 2018.

Hypoxia is a physiological symptom caused by too little oxygen in the body. Similar issues include hypocapnia, when there is not sufficient carbon dioxide in the blood.

After a several month study, the service concluded that oxygen levels in the T-6 were rapidly fluctuating.

The Air Force has redesigned the onboard oxygen generating system (OBOGS) on the T-6 based on the systems used on the F-15E and A-10. The redesigned OBOGS features a new oxygen concentrator. The new system is expected to be rolled out to the 400-aircraft T-6 fleet over 12-18 months.

The concentrator is designed to easily accept software updates, if the Air Force wants to alter the oxygen concentration in the cockpit, for example.

The service is also designing a prototype with additional oxygen tanks, similar to the system used in the F-15E. This may not be implemented if it is determined that the other fixes have sufficiently addressed the issue.

After consulting with the Navy, the Air Force has also begun periodically purging moisture from the OBOGS, which appears to be helping, officials said.

All of the T-6 upgrades are expected to be completed by 2023 at the latest.