Staff Sgt. George Brennan, a 302nd Maintenance Squadron aerospace propulsion technician, replaces components on a C-130 Hercules aircraft during an isochronal inspection at Peterson Air Force Base, Colorado, July 8, 2019. Isochronal inspections are done on each aircraft at the 302nd Airlift Wing every 540 days. (U.S. Air Force photo by Tech. Sgt. Frank Casciotta)