Julie Garcia

Corpus Christi (Texas) Caller-Times

KINGSVILLE, Texas — The Navy has halted T-45 jet flight training at at least three bases across the USA after instructors complained about the aircrafts' oxygen systems, officials said Wednesday.

More than 100 instructor pilots refused to fly the McDonnell Douglas T-45 Goshawk training jets because of an increase in episodes of lack of oxygen or contaminants in the oxygen systems, according to Fox News. The problems make pilots lightheaded and can cause blackouts.

Training at naval air stations in Kingsville, about 30 miles southwest of Corpus Christi, Texas; Meridian, Miss., about 100 miles east of Jackson, Miss.; and Pensacola, Fla., is affected, Lt. Leslie Hubbell, assistant public affairs officer for Naval Air Forces, U.S. Pacific Fleet, said in email.

"We take the concerns of our aircrew seriously and have directed a three-day safety stand down for the T-45 community to allow time for naval aviation leadership to engage with the pilots, hear their concerns and discuss the risk mitigations as well as the efforts that are ongoing to correct this issue," Hubbell wrote. The almost 200 planes are expected to be back in the air Monday.

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In August, a T-45 jet from Kingsville Naval Air Station crashed in a field. The student and instructors ejected from the plane and survived, according to a base news release.

A month later, a T-45 crashed at the air station in Meridian. U.S. Navy personnel said the T-45 jet aircraft assigned to Training Air Wing One crashed in a heavily wooded area Sept. 6.

The student and instructor pilot also were able to eject safely.

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"Physiological episodes are the No. 1 safety priority and focus area for the Naval Aviation Enterprise and will remain our top safety priority until we fully understand all causal factors and have eliminated (physiological episodes) as a risk to our flight operations," Hubbell wrote.

She would not comment specifically on the crashes because investigations into their causes have not been completed.

The Navy has struggled to solve nagging oxygen problems in the T-45 and in F/A-18 Hornets, a supersonic combat jet, according to the Navy Times. But answers have been elusive.

"This is a complex problem with multiple interrelated potential causal factors," Hubbell wrote. "The root cause of physiological episodes remains unidentified, but engineers are working diligently to find a solution."

Contributing: Melissa Nelson Gabriel, Pensacola (Fla.) News Journal. Follow Julie Garcia on Twitter: @Caller_Jules