U.S. Air Force Staff Sgt. Donald Wallace, a 44th Aircraft Maintenance Unit maintainer, inspects the engine of an F-15 Eagle during routine maintenance, Feb. 14, 2017, on Kadena Air Base, Japan. The mission of the 44th AMU is to ensure serviceable aircraft are able to meet mission requirements, keeping pilots current in training and combat ready. (U.S. Air Force photo by Senior Airman Nick Emerick/Released)