On 26 April 1971, 61-7968, flown by majors Thomas B. Estes and Dewain C. Vick, flew over 15,000 miles (24,000 km) in 10 hours and 30 minutes. This flight was awarded the 1971 Mackay Trophy for the "most meritorious flight of the year" and the 1972 Harmon Trophy for "most outstanding international achievement in the art/science of aeronautics".