U.S. Air Force Staff Sgt. Lenny Buscemi, 94th Aircraft Maintenance Unit dedicated crew chief, runs an operations check before takeoff at Nellis Air Force Base, Nevada, July 18, 2019. Crew chiefs ensure everything from the engines, hydraulic systems, pneumatic and pneudraulics components are working properly. (U.S. Air Force photo by Senior Airman Tristan Biese)