Coy, US license D-70, joined the US Army in 1955 and made his first jump that year in Germany. In 1960 he was elected as a member of the original US Army Parachute Team “Golden Knights”. For nearly ten years assigned to the Army Team, he served as a demonstrator, competitor, team leader, aviator and Instrument Flight Examiner. Coy participated in 132 world accuracy records, day and night. As a competitor he was a member of two US Teams and was a founding member of the Golden Knights 10-way team which marked the entry of the Army Team into the formation skydiving world. Coy also was the chief trainer of the National Guard pilots used for the 1972 World Meet in Tahlequah, Oklahoma.