 In 1921 Hornsby graduated from both the Air Service Pilots' School and the Air Service Bombardment School.He participated in the 1922 experimental bombing of surrendered German battleships as a contemporary of Billy Mitchell, and he won the second place award in the 1926 Liberty Engine Builders' Trophy race.This was an air-race held among fifteen top military pilots at the Sesquicentennial International Exposition in Philadelphia to celebrate the nation's 150th birthday.