All of the Navy's operational T-45C Goshawk training aircraft have now been equipped with a new oxygen-level monitoring system, according to a Navy spokesman.
Additionally, T-45s at depots are in the process of having them installed before they fly, he added.
Rear Adm. Sara Joyner, physiological episode action team lead at the Pentagon, told reporters in October that 65 percent of T-45Cs had received the new oxygen measuring device, known as the CRU-123, and had been cleared to fly.
"What the CRU-123 does for us is it tells us . . . the percent of oxygen and flow going through the system," Joyner said.
In June, the Navy released a comprehensive review of physiological episodes after pilots reported several instances of hypoxia. The service established a Physiological Episode Rapid Response Team to create consistency in the Navy's approach to the problem.
In the 2017 National Defense Authorization Act, Congress directed the Navy to conduct an independent review of physiological episodes dating back to January 2009. The service tapped the NASA Engineering and Safety Center to assess the Navy's physiological episode review effort, factors that may reduce the physiological episode rate and the performance of relevant aircraft subsystems.
According to the report, released in December, the Navy's investigative approach did not rely on a single leader to coordinate and prioritize the efforts, resulting in "organizational stove-piping and the exclusion of key stakeholders." The assessment noted F/A-18 manufacturer Boeing "was not fully involved in investigation efforts until recently."
The House Armed Services tactical air and land forces subcommittee will hold a hearing tomorrow on addressing physiological episodes in attack, fighter and training aircraft.