U.S. Air Force pilots from the 37th Airlift Squadron and an 86th Aircraft Maintenance Squadron flying crew chief solve an error while flying during Operation Castle Forge at Larissa Air Base, Greece, Oct. 15, 2021. Flying crew chiefs are specially trained maintenance personnel and are a regular part of flight crews. Castle Forge is a U.S. Air Forces Europe-Air Forces Africa-led joint, multinational training event. Castle Forge is a U.S. Air Forces Europe-Air Forces Africa-led joint, multinational training event held in the Black Sea region to enable operations alongside NATO allies in Bulgaria, Romania and Greece. (U.S. Air Force photo by Senior Airman Branden Rae)