Tech. Sgt. Mark Graveline performs an operational check on a C-17 Globemaster III aircraft fuel control panel Jan. 1, 2013. 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 7-level aircraft maintainer. Graveline is the 315th Aircraft Maintenance Squadron flying crew chief, Joint Base Pearl Harbor-Hickam, Hawaii (U.S. Air Force Photo/Lt. Col. Bill Walsh)