The Douglas C-74 Globemaster I was developed during the Second World War to serve as a very long range transport, but didn't enter production until just after VJ Day, and only a handful were ever completed.
Work on the C-74 began in January 1942, soon after the US entry into the Second World War. The aim was to produce a large long range transport aircraft that could carry significant loads across the Atlantic and Pacific oceans.
The C-74 was a four engined aircraft with low mounted tapered wings. The prototype was powered by four 3,000hp Pratt & Whitney R-4360-27 twenty-eight cylinder radial engines, which were later replaced by four 3,250hp R-4360-69 engines. The wings had a laminar flow aerofoil, with full span Fowler flaps. The fuselage had a circular cross section which could carry 125 troops, 115 stretchers with medical attendants or up to 48,150lb of cargo (it could carry ten Wright R-3350 radial engines, fifteen Allison V-1710 inline engines, two T-9 light tanks or two 105mm howitzers with all of their support equipment). It came with two onboard cranes, each of which could lift 8,000lb, and had a cargo lift installed just behind the wing trailing edges. There was also a conventional cargo door on the left of the aircraft, just in front of the wings. It had a maximum range of 7,250 miles, enough to fly around the work with only two refueling stops.
Work on the C-74 was slow. Although an order for fifty was placed in June 1942, the first aircraft didn’t make its maiden flight until 5 September 1945, and only fourteen were delivered before production was cancelled in January 1946. At first it had twin 'bubble' cockpit canopies for the pilot and co-pilot, but these made it more difficult for the crew to communication and increased drag, so by 1949 the aircraft had been modified with a conventional cockpit canopy.
During the Berlin airlift the C-74 was used to fly three round trips per week from Alabama to Bermuda to the Azores to Frankfurt, to free up shorter ranged C-54s for the airlift itself.
On 18 November 1949 a C-74 became the first aircraft to carry more than 100 people across the Atlantic, taking 103 passengers and crew from Mobile, Alabama to Marham in England, demonstrating how useful it would have been if available during the Second World War.
The fifth C-74 was used as the basis of the prototype for the Douglas C-124 Globemaster II, a much more successful transport aircraft which became the main heavy logistic cargo aircraft for the USAF.
Engines: Four Pratt & Whitney R-4360-69 twenty-eight cylinder radial engines
Power: 3,250hp each
Wing span: 173ft
Length: 124ft 2in
Height: 43ft 9in
Empty weight: 86,172lb
Loaded weight: 154,128lb
Maximum weight: 172,000lb
Maximum speed: 328mph at 10,000ft
Cruising speed: 212mph
Rate of climb: 2,605ft/ min
Service ceiling: 21,300ft
Normal range: 3,400 miles
Maximum range: 7,250 miles
Payload: 125 troops, 115 stretchers and attendants or 48,150lb cargo