Lockheed L-649 Constellation

The Lockheed L-649 Constellation was the first real civilian version of the Lockheed Constellation line, since the L-049 had been a simple redesign of the military C-69. It was planned as the new standard version of the Constellation, but most airlines chose the L-749, an improved derivative produced alongside it, and most of the few L-649 aircraft built were delivered to and operated by Eastern Air Lines. Lockheed began it as the L-049-84 when Curtiss-Wright offered an improved Wright R-3350 Duplex-Cyclone, and the wing and fuselage structure were strengthened to allow a higher gross weight, while the cabin was redesigned and the insulation increased against the loud engines. The first L-649 flew on 19 October 1946 and was certified in May 1947, the month the first one went to Eastern, although the L-749 entered service a month before it.