LANGLEY AIR FORCE BASE, Va. -- Master Sgt. Jason Colon, enlisted dining in sergeant-at-arms, presents arms to Chief Master Sgt. Kevin Jurgella,president of the mess, during the enlisted dining Dec. 11. The focus of the dining in was to celebrate the 50th anniversary of the rank of Chief Master Sgt. This rank was introduced into the United States Air Force Dec. 1, 1959. (U.S. Air Force photo by Staff Sgt. Jeff Nevison)