Developed from the L-749, the L-1049 Super Constellation first appeared in 1950. The transformation undergone by the L-749 was the longest extension ever made to a propeller airliner. The insertion of fuselage sections increased the length by 5,59 m. Other important modi?cations were the complete reinforcement of the airframe and the ?tting of rectangular portholes, the increase of tank capacity and the installation of new engines. The first L-1049 was put in service on December 15th, 1951 by Eastern. TWA and Eastern Air Lines had the largest fleets of „Super Connie“ aircraft.