The C-133 was the first U.S. Air Force transport to use turbo-prop engines. The Cargomaster was designed to carry complete intercontinental ballistic missiles in addition to other large cargos. Later C-133Bs were built with clam-shell rear loading doors that allowed the Titan missile to be carried in one piece rather than disassembled and more powerful engines that allowed a higher gross weight. The Cargomasters only served from 1957 to the early 1970s due in part to serious problems with metal fatigue in their long thin fuselages. A total of fifty C-133s were built.
60th Military Airlift Wing, Travis AFB, California, 1970
Pima Air & Space Museum