Douglas received orders for DC-8s from Delta, Swissair, and TAI, Trans Canada. Other airlines, such as United Airlines, KLM, Japan Air Lines, and Scandinavian Airlines System SAS, chose the DC-8.

Edwards took Douglas DC-8-43 no. N9604Z for a test flight at Edwards Air Force Base in California. The aircraft exceeded Mach 1—the only intentional supersonic flight by an airliner other than ...