Airman 1st Class Markeis McLeod, recorder, 82nd Aero Medical Dental Squadron, Aerospace and Operational Physiology, annotates everything that goes on during the hypobaric chamber flight, and reaction time at Sheppard Air Force Base, Texas, July 10. The air crew members are being familiarized with altitude and to educate them on how to counteract the threats. (U.S. Air Force photo/Danny Webb/Released)