The Lockheed C-69 Constellation was an aircraft of unprecedented size for the standards of its day but was a pronounced failure in military service although it went on to became one of the most iconic airliners of the immediate post-war era. It was originally designed for a TWA requirement before the project was taken over by the USAAF upon the entry of the US to the war. The "Connie" was characterized by a distninctive curved fuselage, triple fins, tricycle undercarriage, and for its cabin pressurization. Unfortunately, engine problems plagued the C-69 and thus, despite its tremendous range and payload capacity, only a trickle of units went on to be used by the USAAF which promply cancelled most additional orders (and which even forbade flights outside the USA). Still, the few C-69s which remained were used during the Berlin Airlift, another was used as President Eisenhower's personal transport, and a prototype would end up becoming the far more successful C-121.

Based on the Lockheed Model 049, the first military C-69 flew on 9 January 1943 with production comprising the basic C-69 as well as a single C-69C VIP transport. The original prototype would end up becoming the XC-69E, which would later become the C-121 Super Constellation.