The Douglas DC-8, also known as the McDonnell Douglas DC-8, is an early long-range narrow-body jetliner that was designed and manufactured by the American Douglas Aircraft Company.
The project was initiated in 1952 to meet the United States Air Force’s (USAF) requirement for a jet-powered aerial refuelling tanker.
However, after losing the USAF’s tanker competition to the rival Boeing KC-135 Stratotanker in May 1954, Douglas announced in June 1955 its derived jetliner project marketed to civil operators.
In October 1955, Pan Am made the first order along with the competing Boeing 707, and many other airlines soon followed suit.
The first DC-8 was unveiled at Long Beach Airport on April 9, 1958, and made its maiden flight on May 30.
Following Federal Aviation Administration (FAA) certification in August 1959, the DC-8 entered service with Delta Air Lines on September 18.
The four-engine jet aircraft, which permitted six-abreast seating, was initially produced in four 151 ft (46 m) long variants.
The DC-8-10 was powered by Pratt & Whitney JT3C turbojets and had a 273,000 lb (124 t) MTOW, while the DC-8-20 had more powerful JT4A turbojets for a 276,000 lb (125 t) MTOW.
The intercontinental models had more fuel capacity and up to 315,000 lb (143 t) MTOW, powered by JT4As for the Series 30 and by Rolls-Royce Conway turbofans for the Series 40.
The Pratt & Whitney JT3D powered the later DC-8-50 and Super 60 (DC-8-61, -62, and -63) as well as freighter versions, and reached a MTOW of 325,000 lb (147 t).
A stretched DC-8 variant was not initially considered, leading some airlines to order the competing Boeing 707 instead.
The improved Series 60 was announced in April 1965.
The DC-8-61 was stretched by 36 ft (11 m) for 180–220 seats in mixed-class and a MTOW of 325,000 lb (147 t).
It first flew on March 14, 1966, was certified on September 2, 1966, and entered service with United Airlines in February 1967.
The long-range DC-8-62 followed in April 1967, stretched by 7 ft (2.1 m), could seat up to 189 passengers over 5,200 nmi (9,600 km) with a larger wing for a MTOW up to 350,000 lb (159 t).
The DC-8-63 had the long fuselage and the enlarged wing, freighters MTOW reached 355,000 lb (161 t).
The DC-8 was produced until 1972, with 556 aircraft built.
It was superseded by larger wide-body airliners, including Douglas’ DC-10 trijet.
Noise concerns stimulated demand for a quieter variant, and from 1975, Douglas and General Electric offered the Series 70 retrofit, powered by the quieter and more fuel-efficient CFM56 turbofan engine.
The DC-8 largely exited passenger service during the 1980s and 1990s, but some re-engine DC-8s remain in use as freighters.
At the conclusion of World War II, Douglas emerged as the pre-eminent North American producer of aircraft in the commercial aviation market.
Despite Boeing’s introduction of the innovative all-metal Model 247 airliner in 1933, as well as the production of significant quantities of the robust four-engine B-17 Flying Fortress and the sophisticated, pressurized long-range B-29 Superfortress, Douglas remained the dominant civil aircraft manufacturer in the United States.
Throughout the 1930s, 1940s, and 1950s, Douglas produced a series of piston-engine aircraft, including the DC-2, DC-3, DC-4, DC-5, DC-6, and DC-7.
While de Havilland achieved the distinction of flying the world’s first jet airliner, the Comet, in May 1949, Douglas initially refrained from developing a jet airliner.
The pioneering Comet entered airline service in May 1952, initially appearing to be a success.
However, the Comet was grounded in 1954 after two fatal accidents, which were subsequently attributed to rapid metal fatigue failure of the pressure cabin.
The investigation into the Comet losses provided valuable findings and experiences for various aircraft manufacturers, with Douglas paying significant attention to detail in the design of the DC-8’s pressure cabin.
By 1952, Douglas had continued its success as a commercial aircraft manufacturer, having received almost 300 orders for its piston-engine DC-6 and its successor, the DC-7, which had yet to fly.
The Comet disasters, and the airlines’ subsequent lack of interest in jets, appeared to validate the company’s decision to remain with propeller-driven aircraft.
However, its inaction enabled rival manufacturers to take the lead instead.
As early as 1949, Boeing had commenced design work on a pure jet airliner.
Boeing’s military arm had experience with large long-range jets, such as the B-47 Stratojet and the B-52 Stratofortress strategic bombers.
While producing and supporting these bombers for the United States Air Force (USAF), Boeing developed a close relationship with the USAF’s Strategic Air Command (SAC).
The company also supplied the SAC’s refuelling aircraft, the piston-engine KC-97 Stratofreighters, but these proved to be too slow and low-flying to easily work with the new jet bombers.
The B-52, in particular, had to descend from its cruising altitude and then slow almost to its stall speed to refuel from the KC-97.
Believing that a requirement for a jet-powered tanker was inevitable, Boeing began work on a new jet aircraft for this role that could be adapted into an airliner.
As an airliner, it would have a similar seating capacity to the Comet, but the use of a swept wing enabled a higher cruising speed and better range.
First presented in 1950 as the Model 473-60C, Boeing failed to generate any interest from airlines.
Nevertheless, the company remained confident that the project was worthwhile and proceeded with a prototype, the Boeing 367-80 (“Dash-80”).
After investing $16 million of its own funds to construct it, the Dash-80 was unveiled on May 15, 1954.
Variants Series 10 Series 20 Series 30 Series 40 Series 50 Series Super 60 Series Super 70 Specifications Series 50 Passengers 189 Max. cargo 1,390 cu ft (39 m3) Wingspan 142.4 ft (43.4 m) Length 187.4 ft (57.1 m) Fuselage Outside width 147 in (373.4 cm), Inside width 138.25 in (351.2 cm) Max. Take-off Weight
(MTOW) 325,000 lb (147.4 t) Max payload 52,000 lb (23.6 t) Operating empty weight 138,266 lb (62.7 t) Max. fuel 24,275 US gal (91.9 m3) Engines P&W JT3D-3B Cruise speed Mach 0.82 (483 kn; 895 km/h) Range 4,700 nmi (8,700 km) Freighter Versions Volume 9,020 cu ft (255 m3) Payload 92,770 lb (42.1 t) OEW 131,230 lb (59.5 t) Max PL Range 3,000 nmi (5,600 km). Sources
NASA Air Mobility Command Museum. 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. Charles Daniels Photo Collection.
