Delta placed an order with Lockheed for the new L-1011 TriStar in 1968, but with Rolls Royce facing bankruptcy in 1971, the engine program was falling behind schedule. As protection in case of delay and cancellation of its L-1011 deliveries, Delta decided to fill the gap with another wide-body jet, the McDonnell Douglas DC-10. "Order of a minimum fleet of DC-10s," said Charles Dolson, Delta's Board chairman and CEO, "will assure Delta's maintenance of a competitive posture over its domestic routes during the 1972-1973 time period. Delta will continue to study possible long-range solutions to the Lockheed-Rolls Royce problems."
Delta ordered five DC-10s on March 18, 1971. These were sold to United Airlines and leased back to Delta from October 1972 to May 1975. The planes arrived at Delta in late 1972 and early 1973. Delta assigned them Ship Numbers 601-605 (N601DA-N605DA).
Delta started DC-10 service on December 15, 1972, from Atlanta to New York-LaGuardia, and expanded to the following markets:
When Delta started Lockheed L-1011 service in late 1973, it was the first airline to simultaneously operate three of the first generation wide-bodied jets—the Boeing 747, Douglas DC-10, and L-1011.
Delta's first DC-10 service ended on May 1, 1975, and the leased planes were returned to United Air Lines.