Between 1948 and 1955 the USAF ordered 150 C-121s for use as cargo and passenger carriers, executive transports and airborne early warning picket ships. This is the only
VC-121E ever built. President Eisenhower
used this aircraft as his presidential aircraft between 1954 and 1961.
Lockheed
VC-121E
Constellation
The C-121 is the military version of the Lockheed Constellation commercial transport. During World War II, the USAAF purchased 22 early model Constellations, which were designated C-69s.