
Vance Air Force Base in Oklahoma has grounded its T-6A Texan II trainer planes while it investigates a series of recent physiological events, the Air Force said last week.Flights of the turboprops were suspended Nov. 15 after instructor and student pilots reported four physiological incidents since Nov. 1, the Air Force said. While the Air Force did not disclose details about the incidents, it indicated that in each case, the aircraft's backup oxygen system worked properly, allowing the plane to…