left U.S. Air Force Staff Sgt. Samuel Allen and Senior Airman Sigfredo Mongevillanueva, 20th Component Maintenance Squadron jet engine craftsmen, prepare to start a jet engine inside a control booth at the engine test facility, Shaw Air Force Base, S.C., March 13, 2014. Two computers inside the booth give exact measurements of temperature, vibration and fuel pressure from the jet engine while fuel is injected into the engine. (U.S. Air Force photo by Airman 1st Class Jensen Stidham/Released)