In 1925, at the age of 18, he joined Tex Rankin's Flying Circus "as a ticket taker, a prop turner, a wing walker and an aerial acrobat". He soloed after two hours and 15 minutes of flying lessons and purchased his own Jenny for $500, using money borrowed from customers on his newspaper route. For two years beginning in 1928, he worked for Fairchild Aerial Surveys, flying photographers to map Mexico in a De Haviland DH-4. That same year, the United States government issued its first pilot's licenses; Jeppesen had Oregon's 27th license. His pilot license number was 7034 and was signed in ink by Orville Wright. His Mexican pilot license is 34.