SCOTT AIR FORCE BASE, Ill. -- Air Mobility Command prepares for a change of command ceremony Friday at 10 a.m. at the Parade Field as Gen. Raymond Johns Jr., relinquishes command to Gen. Paul Selva. Officiating the ceremony will be the Air Force Chief of Staff, Gen. Mark Welsh. Johns, who took command of AMC in 2009, is retiring after serving 35 years on active duty. Selva arrives from Hawaii where he served as vice commander for the Pacific Air Forces at Joint-Base Pearl Harbor-Hickam. He was stationed here previously with the 618th Air and Space Operations Center (TACC) and with U.S. Transportation Command. Full coverage of the event will be posted online at www.scott.af.mil after the ceremony.