LANGLEY AIR FORCE BASE, Va -- Tech. Sgt. Richard Cadgan, 633d Medical Group Aerospace and Physiology instructor, shows Air Combat Command Chief Master Sgt. Martin Klukas the mechanics of the reduced oxygen breathing device during a base tour Aug. 10. The RBD is a training device pilots use to test their flying altitude. Chief Klukas toured the base Aug. 9 and 10, interacting with the Airmen of all squadrons to better understand their work force and needs. (U.S. Air Force photo/Staff Sgt. Ashley Hawkins)(RELEASED)