Then a bulletin board notice changed his life.  It said that OCS men who were under 25 years old could volunteer for the Signal Corps Aviation Section.  He stepped forward quickly and was sent to Austin for preflight school in the summer of 1917.  Lt Eubank was found to be an excellent pilot and held over to be an instructor pilot for the rest of World War I.  In the spring of 1918, Lt Eubank was instructing in ?Jennies? at Kelly Field.

In 1919, Billy Mitchell sent him to the border patrol, flying the DH-4s.  There, in the company with the likes of Jimmy Doolittle, Muir Fairchild, George Kenny, Harry Johnson, and others, he learned how to fly and how to survive in the mountains and desert.  It was a crucial period for military aviation.

His aviation career would span three wars and 37 years.  At the climax of his career, Gen Eubank commanded the Technical Training Air Force.  He had ten bases under his command along with nearly a quarter of a million officers and airmen.  When he retired in 1954 at age 62, he had more than 14,000 flying hours and was the oldest active pilot in the US Air Force.