Meet one of the U.S. Navy's trainer aircraft for pilots-in-training.

WASHINGTON — In response to a growing number of physiological episodes where pilots reported feeling dangerously short of oxygen, the U.S. Navy will equip all of its T-45 training jets with new oxygen-level monitoring systems by February, a Mississippi senator said Wednesday.

The Navy has already upgraded some of its T-45 Goshawks with the CRU-123 — an upgraded, digital version of the current CRU-99 oxygen monitor — but the announcement by Republican Sen. Roger Wicker marks the first time a target date has been disclosed for furnishing all of the training jets with the new system.

“Combined with other recent upgrades, this step should help alert pilots to dangerous declines in oxygen production or pressure levels,” Wicker said in a news release outlining several new steps taken by the service to alleviate growing concerns about physiological episodes.

“The Navy has also grounded any T-45 lacking the full collection of modifications,” he added. “In addition, the Navy is developing a new automatic backup oxygen system scheduled for future installation across the T-45 fleet.”

T-45 pilots, as well as pilots from the F/A-18 Hornet, F/A-18E/F Super Hornet and E/A-18G Growler communities, have reported a increased number of physiological episodes. Similar symptoms could be caused by various conditions such as oxygen deprivation or oxygen contamination, making it difficult to determine what is causing the issue.

And although the Navy has conducted a comprehensive review of the problem, the root cause still remains elusive.

In October, a T-45 crash in Tennessee resulted in the deaths of an instructor pilot and student pilot. It’s still unknown whether physiological factors like oxygen deprivation could have contributed to the crash, but the incident has made finding a solution to the physiological episodes even more urgent.

Unfortunately, the military’s physiological problem isn’t limited only to naval aircraft. The Air Force has also documented an increase in events for F-35 pilots at Luke Air Force Base, Arizona, and T-6 trainer pilots at Vance Air Force Base, Oklahoma. Both planes were grounded for a short period of time earlier this year, but have since returned to normal operations.

On Tuesday, President Donald Trump signed into law the 2018 National Defense Authorization Act. The bill contained several provisions meant to help the services get a better handle on the physiological dilemma.

The most attention-grabbing language allows the Defense Department to authorize a competition, with a prize of up to $10 million, to whoever can isolate the root cause or causes of the services’ physiological episodes.

Another portion of the NDAA directs the Navy to provide regular updates to Congress on what the service is doing to address the episodes, how much money has been spent on those activities and future courses of action.

The House Armed Services Committee’s Tactical Air and Land Forces Subcommittee was set to meet Wednesday for a hearing on physiological episodes across the Air Force and Navy, but the panel was canceled early into the afternoon.