Airman Ryan D. Elmer, from Santa Rosa, Calif., stands in front of a self-generating nitrogen servicing cart, a piece of aerospace ground equipment used in servicing aircraft he learned to maintain and repair en route to "acing" the 361st Training Squadron's aerospace ground equipment apprentice course at Sheppard Air Force Base, Texas, in November 2019. Elmer achieved perfect scores on 15 blocks of instruction during the 87 training day course. He graduated Nov. 27. (U.S. Air Force photo by Staff Sgt. Abhishek Dohare)