Ryan began his flying career in 1917 when he enrolled in the American School of Aviation at Venice, California."Claude Ryan." Aerofiles. Retrieved: May 9, 2012. After making his first solo flight, he was accepted into the Army Air Service with an under-age waiver. The day that he was to report, the armistice was signed, ending his prospects for a military flying career. Instead, Ryan went to Oregon State College and studied Engineering, then was accepted into the Aeronautical Division of the U.S. Army (later known as the United States Army Air Corps). While in the Army, Ryan learned to fly at March Field, California, from where he graduated in 1921."T. Claude Ryan." allstar. Retrieved: May 9, 2012. Ryan flew forestry patrol duty until his enlistment ended in 1922. Ryan then went to San Diego and sold barnstorming rides to pay for a military surplus Curtiss JN-4 Jenny.
