Tech. Sgt. Mark Graveline, 315th Aircraft Maintenance Squadron flying crew chief, performs a walk-around inspection on a C-17 Globemaster III aircraft Jan. 1, 2012 at Joint Base Pearl Harbor-Hickam, Hawaii. Flying Crew Chiefs are specially trained maintenance personnel who attend a six-week maintenance special operations course in addition to the hundreds of hours of training it takes to become seven-level aircraft maintainer. (U.S. Air Force Photo/Lt. Col. Bill Walsh)