Douglas C-133 Cargomaster: Turboprop Cargo Transport Aircraft

The aircraft we present for today is the one that is regarded as one for the early large-sized turboprop-powered cargo transport aircraft. The name of this aircraft is Douglas C-133 Cargomaster which served the United States Air Force (USAF) back in the late 1950s and 1960s. The aircraft was developed by the aircraft manufacturing company named Douglas Aircraft Company back in the mid-1950s. The Douglas C-133 Cargomaster holds the title of being the only strategic airlifter of the USAF that was powered by turboprop engines before the arrival of Lockheed C-130 Hercules.

The aircraft went on to serve not only the military cargo missions but also served NASA in transporting their rockets for space missions. The aircraft was used by the USAF forcibly until 1970 before the Lockheed C-5 Galaxy made its debut and the Douglas C-133 Cargomaster was retired.

Origin and First Flight:-

The origin of the Douglas C-133 Cargomaster came from the requirement of the USAF for a strategic airlifter and transport aircraft under the designation Logistic Carrier Support System SS402L. this new aircraft was clearly much different from the already present C-124 Globemaster and the C-74 Globemaster as it featured the high mounted wings with external fairings on either side for landing gear and the read loading the side loading doors. These loading doors were to ensure better access to the cargo compartment without compromising the structure. The company that came forward with the design was the Douglas Aircraft Company back in the mid-1950s.

The astonishing thing about such a massive aircraft is that no prototypes were built for checking the aircraft instead the aircraft went into production under designation C-133A. The very first Douglas C-133 Cargomaster made its first flight back on April 23^rd, 1956 and the delivery of the first fleet of Douglas C-133 Cargomaster aircraft was made to the MATS (Military Air Transport Service) back in August of 1957. The MATS used the fleet of nearly 50 for these Douglas C-133 Cargomasters during the US campaign of the Vietnam War.

2 Douglas C-133 Cargomasters built as Test articles:-

The 50 Douglas C-133 Cargomaster aircraft used by MATS were of designation C-133A, of which nearly 35 units were developed and C-133B, of which 15 units were developed. Apart from these 50 units of Douglas C-133 Cargomaster, 1 unit of C-133A and C-133B were also developed which were kept as the Test Articles at the Douglas Long Beach. Both for these aircraft did not have any USAF tail number or the construction number.

Used for transport of ICBMs (Intercontinental Ballistic Missiles):-

The large tail doors, side doors as well as the open cargo area allowed for the Douglas C-133 Cargomaster to be a great transport aircraft for the military. The C-133A units were used for transportation of the large-sized and heavy ICBMs (Intercontinental ballistic missiles) such as Titan and Atlas. In reality, the Douglas C-133 Cargomaster was not built to carry and transport ICBMs but the C-133 project was frozen until 1955 and by that time the designs for ICBMs like Titan and Atlas were firm and made.

As for the C-133B variant of the Douglas C-133 Cargomaster, it was built especially for carrying the ICBMs in a much easier manner as it offered petal doors that would open to its sides. Transportation of the ICBMs like the Minuteman, Titan and Atlas were made easier, safer, faster and cost-effective. The Douglas C-133 Cargomaster served the USAF for transportation of the several hundred of the ICBM called Minuteman as well as other ICBMs.

Transporting rockets for Space Programs of NASA:-

Douglas C-133 Cargomaster not only offered the military cargo transport service but it also did the service for the space exploration agency of USA; NASA. The Douglas C-133 Cargomasters were often used for delivery of the Titan and Atlas rockets to the Cape Canaveral which were then sued as the launch boosters for the space programs like Mercury, Gemini, and Apollo.

After the splash of Apollo 11 capsules, they were also airlifted by the Douglas C-133 Cargomaster aircraft.

Used despite the presence of Douglas C-124 Globemaster:-

For many years, the Douglas C-133 Cargomaster proved to be the only viable cargo transport aircraft of the USAF despite the presence of the much larger and capable Douglas C-124 Globemaster. The reason for it is that the C-124 had a cargo deck that did not allow for carrying much cargo.

Retirement after the arrival of Lockheed C-5 Galaxy:-

It was not until 1971 when the Lockheed C-5 Galaxy was introduced tat the Douglas C-133 Cargomaster fleet was finally retired. The airframe life of the Douglas C-133 Cargomaster was about 10000 hours but that life was extended up to nearly 19000 hours. Due to the severe vibration during its flights, the airframes suffered critical stress corrosion which made these aircraft to be beyond the economic operations. USAF only managed to keep as many of the Douglas C-133 Cargomaster aircraft in service as they could until the C-5 entered the service formally.

Setting unofficial military transport records:-

Douglas C-133 Cargomaster ahs also went on to set many unofficial records which include records for the military transport aircraft on the trans-Pacific and Trans-Atlantic routes. One of the records was for the non-stop flight, it made from the Tachikawa Airfield located in Japan to the Travis Air Force Base located in California. The aircraft completed that flight in 17 hours and 20 minutes back on May 22^nd, 1959. The only official record which was sanctioned by FAI performed by a Douglas C-133 Cargomaster was back in December 1958. It was when a Douglas C-133 Cargomaster lifted the payload weighing about 117900 lbs up to an altitude of nearly 10000 feet at the Dover Air Force Base located in Delaware.

Measurements, powerplant, and performance:-

The Douglas C-133 Cargomaster which was manned by a crew of 6 personnel; 2 pilots, 1 loadmaster, 1 navigator, and 2 flight engineers, was measured for a length of 17.feet and the wingspan of 179.7 feet. With the tail included, the aircraft’s height reached up to about 48.2 feet.

This aircraft was powered by 4 of the Pratt & Whitney T34-P-9W turboprop engines; each of which generated power of 7500HP. This allowed for the Douglas C-133 Cargomaster to fly at a top speed of nearly 360mph for a ferry range of nearly 3560 nautical miles at a maximum altitude of about 32000 feet.

The aircraft when empty would weigh about 109415 lbs while the MTOW (Maximum Take-off weight) of the Douglas C-133 Cargomaster was about 286000lbs making the maximum payload carried by aircraft in service to be 176585 lbs.