Staff Sgt. John Skipper, 57th Aircraft Maintenance Squadron Viper Aircraft Maintanence Unit aerospace propulsion craftsman, uses a torque wrench on an engine generator at Detachment 13, 372nd Training Squadron on Nellis Air Force Base, Nev., Sept. 10, 2015. Torque wrenches are used to verify that a component has been tightened enough that it won’t come loose while the aircraft is in use. (U.S. Air Force photo by Airman 1st Class Rachel Loftis)