The Douglas Aircraft Company, situated in Long Beach, California, constructed the Douglas C-74 Globemaster, a heavy-lift cargo aircraft for the United States.
The aircraft’s development was initiated after the Japanese attack on Pearl Harbor, as the need for a transoceanic heavy-lift military transport aircraft became apparent due to the long distances across the Atlantic and Pacific oceans to combat areas.
In response, Douglas Aircraft Company designed a colossal four-engine aircraft in 1942.
However, production and development modification issues caused the first flight to be postponed until 5 September 1945.
The production contract was terminated following V-J Day, resulting in only 14 aircraft being produced.
Despite its limited production, the C-74 fulfilled the requirement for a long-range strategic airlifter, and the Air Force utilized the subsequent Douglas C-124 Globemaster II in this capacity for many years.
In early 1942, the Douglas Aircraft Company initiated studies at their Santa Monica division to develop a transport aircraft capable of meeting the global logistical requirements of the U.S. military.
The “C-74 Project Group” utilized the company’s DC-4 as a foundation and focused on enhancing its capabilities.
The group’s design philosophy was centred on constructing a “no-frills” aircraft that could accommodate a significant portion of the Army’s large equipment, including light tanks, two 105-millimetre (4.1 in) howitzers with their towing vehicles, two angle bulldozers, and smaller utility vehicles.
This led to the creation of the Douglas Model 415, and a cost-plus contract worth more than $50 million was signed on 25 June 1942 for 50 aircraft and one static test article.
No XC- or YC-74 models were produced.
The first flight of a C-74 took place at 15:09 hrs. on 5 September 1945 at Long Beach, with Ben O. Howard at the controls, and lasted 79 minutes.
The first C-74, 42-65402, was airborne just two months after it rolled off the assembly line.
At the time of its first flight, the C-74 was the largest landplane to enter production, with a maximum weight of 172,000 lb (78,000 kg).
It was capable of carrying 125 soldiers or 48,150 lb (21,840 kg) of cargo over a range of 3,400 mi (5,500 km).
The most notable feature of the C-74 was its cockpit arrangement with separate canopies over the pilot and copilot, which was also used for the XB-42 Mixmaster.
However, this arrangement was unpopular with flight crews, and the aircraft were retrofitted with a more conventional arrangement.
During the aircraft’s lifespan, the radial engines were upgraded to 3,250 hp (2,420 kW) Pratt & Whitney R-4360-49 engines.
The C-74 was 31 ft (9.4 m) longer than the C-54 Skymaster and would be 24 ft (7.3 m) longer than the proposed C-118 Liftmaster.
The second C-74 built, 42-65403, c/n 13914, crashed during flight testing on 5 August 1946 at Torrance, California, when it lost a wing during an overload dive test.
All four crew members bailed out successfully.
The fourth aircraft was diverted to a static test article at Wright Field, Ohio, and virtually every component was tested to destruction between August 1946 and November 1948.
This was done to determine the individual components’ ability to withstand design loads.
The fifth C-74 built was modified to be a prototype for the C-124 Globemaster II, which used the same wing as the C-74 but had a much larger fuselage.
This newer aircraft quickly replaced the C-74 in service.
Douglas had planned to adapt the C-74 into a civil airliner once the war ended. In 1944, Pan American World Airways began negotiations.
Their civilian model would be named the DC-7 by Douglas (Model 415A) and the ‘Clipper Type 9’ by Pan American.
Pan American intended to use the 108-passenger aircraft for international travel between New York, Rio de Janeiro, and other cities.
The primary difference between the military cargo aircraft and the civil airliner was the non-pressurized fuselage of the military C-74 and the pressurized DC-7.
The passenger compartment was to be outfitted with a lounge bar, dining area, and sleeping cabins for night flights.
In June 1945, an order was placed for 26 DC-7 aircraft.
With the need for military aircraft significantly reduced by the end of World War II, the order for 50 military aircraft was cancelled in January 1946 after the production of only 14 aircraft.
This cancellation also ended plans to build an airliner version of the C-74 for the civilian market, as the limited military production run increased the cost per civilian aircraft to over $1,412,000, and Pan American cancelled its order.
Douglas then cancelled the DC-7 designation.
The DC-7 designation was later used for a completely different civilian airliner project in the early 1950s, having no relationship to the C-74. Specifications C-74 Crew 13 Capacity 125 troops, 115 stretchers with medical staff, Or Up to 48,150 lb (21,840 kg) of cargo Length 124 ft 1.5 in (37.833 m) Wingspan 173 ft 3 in (52.81 m) Height 43 ft 9 in (13.34 m) Wing area 2,510 sq ft (233 m2) Empty weight 86,172 lb (39,087 kg) Gross weight 154,128 lb (69,911 kg) Max take-off weight 172,000 lb (78,018 kg) Fuel capacity 11,000 US gal (42,000 L; 9,200 imp gal) in six centre-section integral tanks Powerplant 4 × Pratt & Whitney R-4360-69 Wasp Major /-29s /-49s 28-cylinder,
Air-cooled 4-row radial piston engines, 3,250 hp (2,420 kW) each Propellers 4-bladed Hamilton-Standard or Curtiss-Electric fully-feathering,
Reversible constant-speed propellers Performance Maximum speed 328 mph (528 km/h, 285 kn) at 10,000 ft (3,000 m) Cruise speed 212 mph (341 km/h, 184 kn) Range 3,400 mi (5,500 km, 3,000 nmi) Ferry range 7,250 mi (11,670 km, 6,300 nmi) Service ceiling 21,300 ft (6,500 m) Rate of climb 2,605 ft/min (13.23 m/s) Wing loading 61.4 lb/sq ft (300 kg/m2) Power/mass 0.084 hp/lb (0.138 kW/kg).
Sources Air Force Legends 223, Douglas C-74 Globemaster-Nicholas M. Williams, McDonnell Douglas aircraft since 1920: Volume I-René J Francillon, San Diego Air and Space Museum Archive, The National Museum of the U.S. Air Force.