Douglas DC-8

Douglas DC-8-72 of NASA

the Douglas DC-8 is a four-jet nozzle passenger airplane the Douglas aircraft company. It is a low-wing aircraft with a conventional tail unit. The machine was economically extraordinarily successful. Between 1959 and 1972 altogether 556 machines were delivered. The Douglas DC-8 is the largest airplane, which not when large-capacity aircraft was laid out. A DC-8 was it also, as the first passenger airline the supersound reached. To 21. August 1961 broke through a DC-8-43 in descending flight the sound barrier (Mach 1.012).


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use and the whereabouts

the DC-8 mainly of airlines as passenger plane one used. Starting from the 1960er - years took place an increased use as freight or as freight/passenger combination machine. Altogether 48 airlines in 28 nations were supplied with these machines. A proof for the tenacity of the series is that some the machines more than 100,000 flying hours completed. In June 2004 of the originally delivered machines still 150 begun, mainly as freight machines, 134 machines is turned off was scrapped not ready for operation, 81 went in accidents lost, 189 and 2 ruling itself in museums.

Apart from the civilian use the DC-8 was used also by armed forces from France , Gabon , Spain , Togo - mainly as VIP or transport aircraft. The US-Navy uses a machine as enemy representation airplane . A machine is used of NASA as flying laboratory for the examination of space sensor technology in the atmosphere.

technical design

the trunk of the DC-8 is pressurized implemented in all-metal construction and. The double circular cross-section is characteristic. The cantilever bearing areas have two cross-beams. On the upper side of wing are spoilers. For the lift increase double-slotted flaps are installed.

The bearing areas are defrosted with hot-air. The tail unit is likewise in all-metal construction implemented and cantilever. The horizontal stabilizer is trimable. The chassis is retractable and consists of a dual-tire, controllable nose gear wheel and the main landing gear with two main props and four tires each. All wheels of the main landing gear are provided with disc brakes.

background

the development of the DC-8 began 1952 with preliminary studies for an airplane, which could satisfy apart from passenger transport also appearing the demand of the US Air Force for a tanker for the air refueling of their jet-powered strategic bomber fleet. In the summer 1953 the fundamental basic data of the machine were defined. The US Air Force decided however for Boeing KC-135.

Civilian airlines did not show interest in a nozzle passenger airplane due to the negative experiences with DeHavilland comet - airplanes yet again. Therefore Douglas went at the airlines into the offensive and held intensive conversations across the concrete desires for a jet aircraft. The trunk diameter thereupon slightly increases, in order to be able to offer six seats in a row, which affected itself however also in changes at the wing and at the tail unit.

development

the DC-8 became to 7. June 1955 officially announced. The draft planned 45.90 m a long airplane with a span of 43 m. Dependent on the drives and the fuel capacity the takeoff weight should lie between 120 and 139 tons. First four variants were offered. The break-through for the DC-8 came, when Pan American as well as 20 Boeing ordered 707 also 25 Douglas DC-8. Thereupon ordered also United, national, KLM, Eastern, JAL, SAS, delta air LINEs, Swissair, TAI, Trans Canada and UAT of copies of the airplane.

For the production of the machine in Long Beach a new assembly plant one furnished. The first Serienmaschine left the manufacturing in April 1958. The machine started to its first flight to 30. May 1958.

In order fast the permission to gotten, ten machines were used for test flights. Still some changes resulted during the test flights. The intended airbrakes proved as insufficient and with introduction of the thrust reversing were omitted. In order to improve the low-speed characteristics, slats were installed. The machines proved in the cruising more slowly than computed. Therefore the wingtips had to be again changed, in order to reduce air resistance. The permission became to 31. August 1959 gives.

Thereupon the first machines arrived at 18. September 1959 with United and delta into the airline service.

early series

Douglas DC-8-11 United Airlines
  • the DC-8 series of 10 with that 60.50 kN thrust supplying Pratt & Whitney JT3 C-6 engines was delivered. These machines were primarily appropriate for internal-American flights. The first series of DC-8-11 possessed still the wingtips with too high air resistance. These machines were converted gradually to DC-8-12, which possessed slats and a takeoff weight (MTOW), increased to 123 tons, beside the changed wingtips also. 28 machines were produced by this series.
  • The DC-8 series of 20 was delivered with the 70.80 kN thrust supplying Pratt & Whitney JT4 A-3-Triebwerken. The takeoff weight increased to 125 tons. 34 machines were produced. The first flight of this series took place to 29. November 1958.
  • The DC-8 series of 30 was delivered with the 72.50 kN thrust supplying Pratt & Whitney JT4A-9-Triebwerken. Besides however the fuel capacity was increased around well 33 per cent, in order to be able to serve transkontinentale distances. The first flight took place to 21. February 1959. For this the trunk and the chassis had to be strengthened. The first machines of this series, the DC-8-31, received its permission at the 1. February 1960 with a takeoff weight of 136 tons. The DC-8-32 was similar, permitted however a takeoff weight of 140 tons. The type DC-8-33 possessed 78.40 kN supplying JT4A-11-Triebwerke, a change of the flaps, which made a smaller Spritverbrauch possible in the cruising. The flaps could be driven into a cruising position by 1,5°. The chassis was again strengthened, so that now a takeoff weight of 143 tons was possible. Later many machines of the type -31 and -32 to -33 were converted.
  • The DC-8 series of 40 was equipped as the first passenger airliner at all with turbofan - engines, which were opposite the past turbojets substantially quieter and more economical. Also the smoke development was substantially smaller. Rolls-Royces Conway of engines with 78,40 were used kN thrust. The first flight took place to 23. July 1959, the permission to 24. March 1960. The DC-8-41 had a takeoff weight of 136 tons, while the DC-8-42 exhibited a takeoff weight of 140 tons. The DC-8-43 possessed the same change of flap as the DC-8-33. Beyond that the wing was changed, which meant again somewhat more fuel capacity and first of all a resistance decrease, which increased range by eight per cent and which cruising speed increased by 10 knots. The takeoff weight was with 143 tons. These changes flowed also into all further DC-8-Typen. 32 machines were built by the series of 40.
  • The DC-8 series of 50 possessed likewise turbofan engines, it Pratt & Whitney JT3D -1 with 76,10 kN thrust or JT3D-3B with 80,60 kN thrust was used. The series DC-8-51, DC-8-52 and DC-8-53 differed in their takeoff weights from 126, 138 respectively 142 tons. Late versions of the DC-8-53 exhibited the stronger cells and chassis of the freight versions and had a takeoff weight of 147 tons. The first flight took place to 20. December 1960. 88 machines were built by this series.
  • DC-8 series jet Trader were cargo versions of the DC-8-50. They had a cab for first 54 passengers, behind it, a front cargo with a large freight door, a strengthened cabin floor and. This arrangement was replaced later short time by an adjustable mechanism for the separation of the cargo, which made it possible to carry between 25 and 114 passengers. The first flight took place to 29. October 1962, the permission took place to 29. January 1963. There was also a variant without cab windows, by which however only 15 machines were sold at United Airlines. The DC-8F-54 possessed a takeoff weight of 143 tons, while the DC-8F-55 exhibited a takeoff weight of 147 tons. Both types were propelled by JT3D-3B-Triebwerken with 80,60 kN thrust. A DC-8-54F was converted of the US-Navy, in order to copy as EC-24 to purposes of practice hostile communication and radar systems.

After Excellencies the start of the series ran the sales soon sluggishly. Reason was the business decision of the manufacturer Douglas to offer despite the large number at variants first no shortened or extended cab because the development department with the development the Douglas DC-9 was perfectly working at full capacity. In the year 1964 only 14 machines and of it again a majority were sold as freight machines. Boeing with the 707 showed up in the cab length more flexibly and achieved ever higher market shares.

After conclusion of the development of the DC-9 and their first flight to 25. February 1965 reacted to Douglas in April 1965 and communicated the cab extension for DC-8 with three new models. Also over 250 passenger seats the super in such a way specified Sixties was the largest airplanes of their time, up to the appearance Boeing 747 in the year 1970.

super Sixties

Douglas DC-8-63 als Frachter der MK Airlines
Technical data
of the last series version (DC-8-63)
span 45.24 m
length 57.04 m
height of 13.00 m
cab interior length 42.29 m
cab width 3.50 m
cabin altitude of 2.21 m
wing area 271.93 m 2
wing sweepback 30,6°
maximum takeoff weight 158,757 kg
unloaded weight 89,017 kg
of pay load 30,125 kg
of maximum speed 965 km/h
rate of climb
at ground level
11 m/s
maximum range 12,390 km
of passengers 259
crew 3 cockpit, 5 cab
  • the DC-8 series of 61 was based on the -53 with the same take-off weight. Thus was reduced in relation to range the -53 accordingly. In order to increase the capacity, the front cab was extended by 6 m and the rear by 5 m, which resulted in an overall length of 57 m. The cab had to be strengthened because of the larger loads accordingly. The chassis however did not have to be extended. These machines seized typically 210 passengers, in high-density Bestuhlung could also 269 passengers be carried. The first flight took place to 14. March 1966, the permission took place to 2. September 1966. 88 machines of this type were sold.
  • The DC-8 series of 62 corresponded the -53 and was for be enough-strains laid out. Opposite the -53 the cab was extended only in front and in the back 1.02 at a time m. In order to increase the range, the wingtips were extended by a meter, in order to increase the fuel capacity and to reduce air resistance further, equally the engine hanging and linings were changed. The machine received a slightly larger takeoff weight opposite the -61 from 151 tons and had a range of 9.630 km with full additional load. The first flight took place to 29. August 1966, the permission in April 1967. 67 machines were built of this type.
  • The DC-8 series of 63 was a mixture from the long cab of the -61 and the other improvements of the -62. As drive JT3D-7-Triebwerke with a thrust of 85 served kN. The maximum take-off weight amounted to 159 tons, the range with maximum pay load 7,600 km. The first flight took place to 10. April 1967, the permission to 30. June 1967. 107 machines were built of this type to convert for instance half of it freighters or with the possibility them for the freighter.

The last machine of this type left to 13. May 1972 the assembly workshop, in order by the McDonnell Douglas DC-10 to be replaced.

super Seventies

with the beginning of the 1970er - years began discussions over increasing air traffic and the increasing noise load of airport adjacents resident here. The DC-8-Typen of the series of 61 to 63 was the loudest all jets. With the time the noise became emissions for the airlines the problem: With the loud DC-8-Maschinen they have not might approach some airports any longer.

Therefore with McDonnell Douglas at the beginning of the 1970er-Jahre of some airlines it was inquired whether one could not install quieter engines to the DC-8-Maschinen. First companies with solutions pushed Hushkits so mentioned (muffler) for the reduction of the noise emissions, on the market, these fulfilled however not all expectations. Finally CFMI brought a variant in the play, for which neither McDonnell Douglas nor Boeing could lock with the CFM56-Triebwerk. The development began end of the 1970er-Jahre and led to the super Seventies. No machine was again produced by the super Seventies, on the contrary they are changes of their predecessors.

Douglas DC-8-72 of NASA
  • the DC-8-72 and the DC-8-73 were reequipped without other outward changes from the DC-8-62 and DC-8-63 on the new engines. This were 98.50 kN thrust supplying CFM56-2C5-Turbofan-Triebwerke with high bypass ratio. Alternatively also a Pratt & a Whitney PW JT8D-209 could be used. The cowl was again designed by Grumman. The change was led by the company Cammacorp in Los Angeles. Additionally to the changed engines also a Hilfstriebwerk (APU) was for autonomous current supply as well as an environmental management system available.
  • The DC-8-71 developed from the DC-8-61, experienced however larger modifications, since also the wings and the engine suspension had to be changed. Due to the higher weight of the new engines the pay load was reduced slightly, whereby however the maximum takeoff weight remained unchanged. The first flight of a in such a way reequipped machine took place to 15. August 1981. The permission was given 1982. Altogether to end 1986 110 machines of the DC-8-60er-Serie were modified accordingly.

The change reduced the noise emission by 70 per cent and the engines used by 20 per cent less fuel.

see also

literature

  • Douglas DC-8 von Bernd cousin, GeraNova magazine publishing house 2001 (ISBN 393278586X)
  • Douglas Dc-8: 2 (Great of air liner Series, volume of 2) of Terry Waddington, World transport 1996 (ISBN 0962673056)
  • Boeing 707, Douglas DC-8 & Vickers VC10 (Legends OF the air) of Stewart Wilson, Australian aviation 1998 (ISBN 1875671366)
  • Early American of jet liner: Boeing 707, Douglas DC-8 & Convair 880 of Ugo Vincenzi, Motorbooks international 1999 (ISBN 0760307881)
  • Douglas DC-8 - A Pictorial History of George W. Cearley, self-publishing house 1992 (no ISBN)

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