Donald Greathouse served over 26 years in the U.S. Air Force as an aircraft hydraulic systems craftsman, aircraft pneudraulic systems technician craftsman, and aircraft pneudraulic systems mechanic journeyman from October 1993 to January 2015. He maintained, repaired, and overhauled aircraft hydraulic, pneumatic, and refueling systems. Greathouse also received extensive training in aircraft maintenance, contracting, and leadership through courses at the NCO Academy and NCO Leadership School.