Senior Airman Zachary L. Creek and Senior Airman Brandon L. Johnson position a B1stand as they prepare to measure the gap on a C-17 Globemaster III engine proximity sensor Aug. 3, 2010, at Charleston Air Force Base, S.C. Airman Creek and Airman Johnson are jet engine mechanics with the 315th Aircraft Maintenance Squadron here. (U.S. Air Force photo/Staff Sgt. Shane Ellis)