ELLSWORTH AIR FORCE BASE, S.D. -- Airman 1st Class Jason Pettine, 28th Maintenance Squadron aerospace propulsion apprentice, loosens bolts from a fan duct on a B-1B Lancer engine here, Aug. 13. Airman Pettine removes the fan duct to access blades in need of repair. (U.S. Air Force photo/Airman 1st Class Anthony Sanchelli)