C-133 Cargomaster
The huge C-133 Air Force Cargo Logistical Aircraft was the largest cargo plane in the Free World at the time, and was capable of carrying 100,000 pounds more than 2,000 nautical miles. The Douglas C-133 Cargomaster, a four-engine, turboprop transport, was larger and faster then earlier Douglas military cargo airplanes. The Cargomaster went into production without a prototype and had an unusual circular fuselage with top-mounted wings.
The C-133 could fly the equivalent of 22 loaded railroad boxcars nonstop between Los Angeles and New York for about 5 cents per ton per mile. It carried fully assembled tanks and transported the Douglas-built Thor intermediate range ballistic missiles.
The Douglas YC-133 Cargomaster was originally conceived as an improvement of the C-124 and later redesigned as a high-wing transport with greater performance and range than its predecessor. The Douglas Aircraft Company’s giant C-124 — “Old Shaky” — had a small cargo elevator and could be loaded from the front through clamshell doors, but it sat high off the ground and its loading ramp was steep. Most importantly, it represented 1940s technology, being powered by four 3,600 horsepower radial piston engines.
The Air Force’s global responsibilities increased in the early 1950s, just as the advent of the fuel-efficient turboprop engine promised economical long-range transport capabilities. This led the service to issue a request for its first true strategic airlifter. The new plane would have to be capable of carrying any item of equipment in the Air Force or Army inventory — including the Atlas intercontinental ballistic missile just coming into service. Other requirements were specified as well. In order to speed loading and offloading, it must be low to the ground and have a drive-in back door with a built-in ramp. The cargo compartment must also be fully pressurized so that ground troops and their equipment could be transported.
Douglas responded with the C-133 Cargomaster, a large and elegant design powered by four 6500 horsepower turboprops. Its wing was mounted high in order to keep the spars above the cargo compartment, and at a slight positive angle of attack to help the long fuselage during takeoffs. Side-mounted landing gear also cleared the cargo bay and provided for low ground clearance as well. The payload area was designed around the dimensions of the Atlas, which meant that it could transport the intermediate-range Thor and Jupiter missiles as well.
The C-133 made its maiden flight on April 23, 1956, when Douglas test pilots J.G. Armstrong and Frank C. Boyer flew the new transport from Long Beach to Edwards Air Force Base for Phase I (airworthiness tests conducted by the contractor) and Phase II (contractor compliance conducted by the Air Force Flight Test Center) evaluations. Exhaustive testing, evaluation, and some design refinements eventually resulted in a combat support aircraft that served warfighters well into the Vietnam era.
In August 1967, two years and twenty-seven days after the departure of the 1st Brigade, the remainder of the 101st Airborne Division was alerted for deployment to Vietnam from Fort Campbell, Kentucky. Originally, the Division was scheduled to be in country on 10 February 1968. However, this movement was subsequently rescheduled for early December 1967. The culmination of the Division's preparation for deployment was Operation EAGLE THRUST. This lift was keynoted by the departure on 8 December of the Commanding General, Major General Olinto M. Barsanti, in an aircraft piloted by General Howell M. Estes, Jr., Commander of the Military Airlift Command. On 18 December 1967 the last airplane touched down in Vietnam ending the largest and longest military airlift ever attempted into a combat zone. The move had required 369 C-141 Starlifter aircraft missions and 22 C-133 Cargomaster aircraft missions, ultimately airlifting 10,024 troops and over 5,300 tons of the Division's essential equipment.
Douglas built and delivered the last Cargomasters in 1961. NASA used Cargomasters to drop-test early space capsules and to transport a variety of space products. Douglas built 50 Cargomasters, but after the C-133, Douglas did not built transports specifically for the military for another 10 years.
