Douglas DC-6 / C-118

The US Army Air Forces financed the building of a pressurised prototype aircraft based on the DC-4 but with the square, rather than round, windows which were to be an identifying feature of the future DC-6. The prototype, designated XC-112A, also had 2,100-hp / 1,565kW Pratt & Whitney R-2800-34 Double Wasp engines and an 81-inch extension of its fuselage. The XC-112A flew at Santa Monica on 15 February 1946.

American Airlines placed the first order for 50 examples of the new four-engined Douglas, now called DC-6 and first flown on 29 June 1946. The DC-6 was configured to transport between 52 and 86 passengers, depending upon the class of accommodation used. A total of 175 DC-6 were built.

The windowless DC-6A freighter followed in 1949, powered by 1,788.5kW Double Wasps, with reinforced floor and double cargo doors.

The DC-6A, a strengthened, some-what elongated version powered by water-injection versions of the Double Wasp engine, flew on 29 September 1949. Most DC-6As were built initially as cargo-haulers but were later converted into passenger carriers by their airline users. They had a reinforced floor and cargo-loading doors. The DC-6A was 1.52m longer than the DC-6 (101 going to the USAF as C-118A transports). The term DC-6C was used to refer to aircraft in this series built from the beginning with passenger accommodation. Seventy-four aircraft of the DC-6A/DC-6C type were built, the last being delivered in 1959.

The DC-6B flew on 2 February 1951, a passenger ship lacking the floor and cargo door of its immediate predecessor. Improved 2,500-hp Double Wasp engines with paddle-blade propellers powered the DC-6B. With 288 examples delivered between 1951 and 1958, the DC-6B was the most numerous of variants in the DC-6 series, 704 of which were delivered in all and was put into service on 29 April 1951, by American, Panagra and Braniff, among others.

The DC-6B, with accommodation for 54-102 passengers, first flew on 2 February 1951 and also had the longer fuselage. American Airlines introduced DC-6B on its US transcontinental services on 29 April 1951.

The US Navy was the first military customer to order a DC-6 variant in some numbers, acquiring 65 DC-6As in the late 1940s and early 1950s. These were designated R6D-1 and VIP/staff transport examples were called R6D-1Z. The single C-118 (length 100ft 7 in) is V.I.P. transport.

R6D-1

After the Navy, the US Air Force acquired 101 DC-6A aeroplanes, designated C-118A, and employed them on MATS’ worldwide routes. These aircraft could carry up to 27,000 lb of cargo or 81 fully-armed troops. In 1962, the two Naval variants were redesignated C-118B and VC-118B and 40 of them were transferred to the USAF.

Regularly scheduled operations of the commercial passenger DC-6 continued until 1967 and many of the DC-6 series were later converted to freighters.

Gallery

XC-112A
Engines: 4 x Pratt & Whitney R-2800-34 Double Wasp, 2,100-hp.
Wing span: 117 ft 6in.
Wing area: 1,463 sq.ft.
Length: 100 ft 7in.
Height: 29ft 1 in.
Empty weight: 53,623 lb.
Max take-off weight: 97,2001b.
ROC: 900 fpm.
Cruise: 328mph.
Service ceiling: 29,000ft.

DC-6
Engines: 4 x Pratt & Whitney R-2800-34 Double Wasp, 2,100-hp.
Wing span: 117 ft 6in.
Wing area: 1,463 sq.ft.
Length: 100 ft 7in.
Height: 29ft 1 in.
Empty weight: 53,623 lb.
Max take-off weight: 97,2001b.
ROC: 900 fpm.
Cruise: 328mph.
Service ceiling: 29,000ft.

DC-6A
Engines: 4 x Pratt & Whitney R-2800 Double Wasp.

DC-6B
Power: 4 x Pratt & Whitney R-2800 Double Wasp radials, 2400 hp.
Max speed: 356 mph @ 20,000 ft.
Span: 117 ft 6 in.
Length: 100 ft 7 in.
MAUW: 97,200 lbs.
Range: 3860 mile.
Cruise: 328mph.
Pax cap: 107.

DC-6BF
Engines: 4 x Pratt & Whitney R-2800-CB Double Wasp, 2400 hp.
Wing span: 117 ft 6 in.
Length: 103 ft 6 in.
Height: 28 ft 6 in.
MTOW: 103,800 lb.
Empty wt: 56,000 lb.
Cruise: 225 kt. 

R6D-1
Military transport.
Engines: 4x Pratt & Whitney R2800-52W, 2,500 h.p.
Wingspan: 117 ft. 6 in.
Length: 105 ft. 7 in.
Loaded weight: 106,000 lb.
Max. speed: 360 m.p.h.
Typical range: 3,860 miles at 307 m. p. h. at 22,400 ft.
Capacity: 60-76 passengers or 40 stretchers.

C-118
Length: 100 ft 7 in

C-118A
Payload: 27,000 lb or 81 fully-armed troops.

C-118B Liftmaster