What did Lockheed do to build the Super Constellation prototype?

The development of the Super Constellation as a successor to the Constellation responded to a shift in demand. The growing number of passengers led Lockheed, in 1950, to stretch the already long Constellation fuselage with additional segments ahead of and behind the wings, adding 5.59 m in total.

Lockheed no longer had a test aircraft, so it bought back the Constellation prototype, the XC-69, from the US Air Force (USAF) and turned it into the L-1049 Super Constellation. Besides the stretch, the main changes were reinforcement of the entire structure, square cabin windows, a modified cockpit glazing, greater fuel capacity, and more powerful Wright R-3350-CB1 engines. The Super Constellation flew for the first time on 13 October 1950.

The new model proved very economical to operate, but its engine power barely met what the airlines were asking for, so only 24 L-1049s of the first series were built, for Eastern Air Lines and TWA. Later versions fixed the problem, and the family grew with models such as the L-1049C, the L-1049E, and the L-1049G, the most successful version, which first flew on 7 December 1954. The line ended with the mixed-use L-1049H, introduced in 1957. Thus the aircraft that had opened the Constellation saga ended up also serving as the starting point for its best-known version. From its first flight in 1950 to November 2023, the L-1049 recorded 111 total losses, 58 of them fatal, in which 1,094 people died.