The bulk of the unexplained physiological events ― 10 of them ― occurred at Columbus Air Force Base in Mississippi, said AETC spokeswoman 1st Lt. Geneva Croxton in an email. Two other events occurred at Vance Air Force Base in Oklahoma, and another happened at Sheppard Air Force Base in Texas.
Croxton said that 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.
“Each event is being investigated, and it is too early to speculate about potential causes,” Croxton said.
In response to reports of hypoxia-like symptoms experienced by F-35A pilots at Luke Air Force Base, Arizona, the program office intends to make changes to the onboard oxygen generating system to optimize the flow of oxygen to those flying the jet.
AETC announced the “operational pause” Wednesday evening, and said it was ordered by Maj. Gen. Patrick Doherty, commander of the 19th Air Force, to give the Air Force a chance to study the root cause of these problems, listen to and educate air crew, find solutions, and put them into place. The grounding took effect Thursday.
Earlier on Wednesday, AETC confirmed that the 19th had suspended all solo flights in T-6s due to concerns about events like hypoxia.