The Douglas Aircraft Company constructed the Douglas C-133 Cargomaster, a sizeable American turboprop cargo aircraft, from 1956 to 1961 for employment by the United States Air Force.
The C-133 was the sole strategic airlifter of the USAF that was powered by turboprop and was commissioned into service soon after the Lockheed C-130 Hercules, which was classified as a tactical airlifter.
The C-133 was utilized for a diverse array of airlift operations and was eventually succeeded by the C-5 Galaxy in the early 1970s.
The C-133 was developed to fulfil the requirements of the USAF’s Logistic Carrier Support System SS402L for a new strategic transport.
This aircraft differed significantly from its predecessors, the C-74 Globemaster and C-124 Globemaster IIs.
It featured a high-mounted wing, external blister fairings on each side for the landing gear, and rear-loading and side-loading doors, which ensured that access to, and the volume of, the large cargo compartment were not compromised by these structures.
The cargo compartment, measuring 90 ft/27 m in length and 12 ft/3.7 m in height, was pressurized, heated, and ventilated.
The Cargomasters were produced directly as C-133A, without any prototypes being built.
The first Cargomaster took its maiden flight on 23 April 1956.
The initial C-133As were delivered to the Military Air Transport Service (MATS) in August 1957 and began flying MATS air routes worldwide.
Two C-133s set transatlantic speed records for transport aircraft on their first flights to Europe.
The fleet of 50 aircraft proved to be invaluable during the Vietnam War.
However, the Cargomaster was eventually replaced by the Lockheed C-5 Galaxy, which entered service in the early 1970s.
The C-133 was subsequently retired, and most of the planes were dismantled within months of being delivered to Davis-Monthan Air Force Base, Tucson, Arizona, after their final flights in 1971.
The USAF constructed 50 aircraft (35 C-133A and 15 C-133B) and put them into service.
A single C-133A and a C-133B were built and kept at Douglas Long Beach as “test articles,” without construction numbers or USAF tail numbers.
The C-133 had large tail doors and side doors and a large, open cargo area.
The C-133A carried many large and heavy loads, including Atlas and Titan ICBMs, although it was not designed specifically for this purpose.
The C-133 design was finalized by 1955 to build the planes that first flew in April 1956.
The designs of both the Atlas and Titan were not firm until after 1955 when their contracts were signed.
With the C-133B, the rear cargo doors were modified to open to the side (petal doors), making ICBM loading much easier.
Air transporting ballistic missiles such as the Atlas, Titan, and Minuteman was much less expensive, safer, and faster than road transport.
Several hundred Minuteman and other ICBMs were airlifted to and from their operational bases by C-133s.
The C-133 also transported Atlas, Saturn, and Titan rockets to Cape Canaveral for use as launch boosters in the Gemini, Mercury, and Apollo space programs.
After the Apollo capsules splashed down, they were airlifted in C-133s from Naval Station Norfolk, Virginia, or Hickam AFB, Hawaii, to Ellington AFB, Texas, or California. Specifications C-133B Crew Five Capacity 200 passengers or 110,000 lb (50,000 kg) Length 154 ft 3 in (47.01 m) Wingspan 179 ft 9 in (54.78 m) Height 48 ft 3 in (14.7 m) Wing area 2,673 sq ft (248.3 m2) Empty weight 120,263 lb (54,550 kg) Gross weight 275,000 lb (124,738 kg) Max take-off weight 286,000 lb (129,727 kg) Powerplant 4 × Pratt & Whitney T34-P-9W turboprop engines,
7,500 hp (5,600 kW) each with water injection Propellers 3-bladed Curtiss Electric fully feathering, reversible-pitch propellers. Performance Maximum speed 312 kn (359 mph, 578 km/h) at 8,700 ft (2,700 m) Cruise speed 281 kn (323 mph, 520 km/h) Range 3,560 nmi (4,100 mi, 6,590 km) with 52,000 lb (24,000 kg) payload Service ceiling 29,950 ft (9,130 m) service ceiling Rate of climb 1,280 ft/min (6.5 m/s) Wing loading 102.9 lb/sq ft (502 kg/m2) Power/mass 0.1087 hp/lb (0.1787 kW/kg).
Sources
Air Mobility Command Museum.
McDonnell Douglas aircraft since 1920: Volume I-René J Francillon.
Remembering an Unsung Giant, The Douglas C-133 Cargomaster and Its People–Cal Taylor.
