Airman Bridie Eckenrode, 361st Training Squadron student, installs a propeller retaining nut onto a T-56 Rolls Royce turboprop engine at Sheppard Air Force Base, Texas, May 24, 2017. This model propeller and engine combination are installed onto the C-130H aircraft. (U.S. Air Force photo by Liz H. Colunga/Released)