13 hypoxia-like events in one week led to USAF T-6 fleet grounding

The 19th Air Force’s fleet of T-6 trainers were grounded after 13 unexplained events, such as hypoxia in a single week.
The bulk of the unexplained physiological events ― 10 of them ― occurred at Columbus Air Force Base in Mississippi. Two other events occurred at Vance Air Force Base in Oklahoma, and another happened at Sheppard Air Force Base in Texas.
The unexplained events included conditions such as hypoxia, or too little oxygen in the body; hypocapnia, or too little carbon dioxide in the blood; and hypercapnia, or too much carbon dioxide in the blood.
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