Staff Sgt. Jonathan Daniels, 62nd Maintenance Squadron jet mechanic, tightens a part on the electronic engine system for a C-17 Globemaster III on Joint Base Lewis-McChord, Wash., May 20, 2020. Jet mechanics specialize in work on the engines of C-17s, whereas crew chiefs conduct maintenance on other areas of the aircraft. (U.S. Air Force photo by Airman 1st Class Mikayla Heineck)