FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1957
1957 - 1588.PDF
676 FLIGHT, 1 November 1957 AIRLINERS OF THE WORLD VISCOUNT 8IO . . . lage is built as one unit between the pressure bulkheads. Overall floor loading is 100 lb/sq ft, with 150 acceptable m certain areas The passenger windows, 26 in number (or 28 with a rear lounge) are vertical ellipses measuring 26in by 19in. Six windows above the wing are emergency exits, together with another window forward to the starboard. Whereas earlier Viscounts had elliptical doors, the 810—like the intermediate 800 series—has rectangular doors with rounded corners.- The main passenger entry door measures 64in by 36in, is situated forward of the wing on the port side, and can incorporate a power-folding airstair. It is hinged at the rear edge (parallel motion). On each side of the aircraft two further doors at the aft end can be used as emergency exits or for passenger loading. They measure 64in by 27in each and are similarly hinged. Two further doors, on the starboard side for- ward of the wing and below floor level, provide access to the under-floor freight hold. There is provision also for a further door on the starboard side at the extreme aft end for access to the rear freight compartment (this area is available as a lounge). Wing Each wing is built up in three sections: inner, outer and a detachable tip. The nacelles are mounted on the inner section. Flexible fuel tanks are fitted in both inner and outer sections, and a water /methanol tank in each inner section. Thick- ness chord ratio is 15.5 per cent at the root and 13 per cent at the tip. The primary structure consists of a main spar at 0.4 of the wing chord and subsidiary spars at 0.05 and 0.7 chord. The spars, together with the top and bottom skin panels, complete the torsion box. The main spar of each inner section is attached to the fuselage by control-interference fit taper bolts; the subsidiary spar members are each attached to the fuselage by four bolts. The ailerons are each built in two sections to avoid hinge friction, and are of conventional construction. The flaps are of the double- slotted type, built in three sections. Tail Unit The tailplane is set at 13 deg 43 min dihedral, and is of symmetrical section, comprising a single spar. The elevators are of conventional construction; a trim tab is fitted to the star- board unit, and a spring tab and a gear anti-balance tab to the port elevator. The fin and rudder are of conventional construction; a combined trim and spring servo tab is fitted to the rudder, which incorporates a horn balance. Undercarriage Each undercarriage unit, main and nose, in- corporates a single Vickers oleo pneumatic shock absorber on which twin wheels are mounted. The nosewheels are steerable through 50 deg either way. The wheels and brakes, which include an anti-skid device, may be either Dunlop or Goodyear. Tyre pressure of the main wheels is 120 lb/sq in, and of the nosewheels 90 lb/sq in. POWERPLANT The engines of the Viscount 810 are the Rolls-Royce Dart R.Da.7/1 (Mark 525) driving Rotol four- bladed ("trapezoidal" planform) constant speed propellers. The Dan 525 develops 1,990 total equivalent horsepower, or 1,800 shaft horsepower. The engine of the Viscount 840 is the Dart R.Da.ll (Mark 541) which develops 2,350 total equivalent horse- power or 2,100 shaft horsepower. This engine will be available in 1959. Both the 525 and the 541 have a two-stage centrifugal compressor with single-entry impellers, seven interconnected straight flow combustion chambers, and a three-stage axial flow turbine (one more stage than previous Darts). SYSTEMS Flying Controls The flying controls are conven-tional in design and operate the control surfaces through push-pull rods and levers. Fuel System The fuel system is designed to use British, Americanand Canadian grades of either kerosine or wide-cut gasoline. The fuel is carried in the wings, in a total of four tanks, each consisting of anumber of interconnected flexible bag type cells. Usable fuel capacity of each outboard tank is 292 Imp. gal, and that of each inboard tankis 658 Imp. gal, making a total usable fuel capacity of 1,900 Imp. gal (2.282 U.S. gal). Two 145 gal slipper tanks are optional. Cabin Air The whole of the fuselage, with the exception of the noseportion, and nosewheel bay and tail portion, is designed for pressuriza- tion to a differential pressure of 6.5 lb/sq in. Three Roots type cabinsuperchargers mounted on the engine-driven accessory gear boxes pro- vide an air supply of approximately 75 lb/min at 25,000ft. The pressurecontrol equipment is by AiResearch. Cabin sea level conditions can be maintained up to 15,000ft, and 8,000ft conditions up to 30,000ft. Cabinrate of climb is automatically limited. A safety valve is provided to blow off at 6.75 lb/sq in and a twin inward-relief valve is fitted. De-icing Airframe thermal de-icing utilizes engine exhaust heatedram air ducted to the leading edges of the mainplanes, tailplane and fin. The windshield is de-iced by alcohol fluid. The propeller blades,spinners and engine and oil cooler air intakes are de-iced electrically by heating elements operating at 208v A.C. Hydraulics The system provides power for raising and lowering theundercarriage, application of wheel brakes, and nosewheel steering. Hydraulic power is supplied by two Lockheed Mk 9 pumps driven bythe two inboard engines. Operating pressure is 2,000-2,500 lb/sq in and either pump will provide sufficient power for the whole system. Electrics The main electrical installation operates at 27Jv D.C.derived from four 9kW generators, one driven by each engine. Three 24v 25 amp/hr batteries are provided to maintain electrical supplywith engines off, and there is provision for a fourth battery when engine internal starting is required. FLIGHT DECK The cockpit layout provides for a flight crewof two, but a supernumerary crew member can be accommodated if required in a jump seat folding flat on the floor when not in use. PAYLOAD ACCOMMODATION Typical standard seatingaccommodation is 8 passengers four abreast in the forward cabin, and M Dassengers four abreast in the main cabin, a total of 52 passengers.In the 56-seat version, the area occupied by the aft-end wardrobes and freight compartment in the standard aircraft is utilized to provide alounge with a wardrobe, this arrangement providing additional seating for four passengers in the lounge. International standard seat tracks arefitted. Two toilets with adjoining washrooms are provided between the two cabins in the line of the propellers. Two pantry buffets are providedat the rear of the main cabin. A large main freighthold is provided under the cabin floor betweenthe nosewheel bay and the wing leading edee, access being through two doors on the starboard side of the aircraft. Its gross volume is 250 cu ft.In addition, the standard aircraft has a freight compartment at the extreme aft end of the cabin of 120 cu ft gross, accessible through itsown door on the starboard side of the aircraft. Spare stowage area (250 cu ft) is available in the vestibule opposite the passengers' entrancedoor. It is possible, subject to balance and structural considerations, to fill these three freight compartments respectively as follows: 3,725 lb,2,140 1b, 550 lb. COMMERCIAL HISTORY Originally the basic V.C.2 design,which owed its origin to Brabazon Committee recommendations, was much smaller than the present Viscount, weighing about 30,000 1b.That was in 1945. Early history of the type was uncertain, and in the summer of 1948 the Viscount seemed to be doomed. But at this pointthere began a process of increasing the Dower of the Roll-Royce Dart and stretching and increasing the weight of the airframe—measureswhich saved the aircraft. A fleet of 20 Viscount 701s was ordered by B.E.A. in 1950. The first Droduction machines were delivered in early1953 at a weight of 56,000 lb. Passenger capacity was 47, and the engines were Dart 505s of 1,400 s.h.o. The first commercial scheduleservices were inaugurated in April 1953. Since 1954 power and weight went up, and today the latest Viscount 700Ds aircraft can operate at63,000 lb. The Suffix "D" denotes the installation of the Dart 510 of 1,600 s.h.p. During 1952 B.E.A. ordered the first of a new family of the then-called Viscount Majors, designated 800 Series. The fuselage of this series was sTetched 46in ahead of the wing, and in addition the rearpressure bulkhead was moved back 65in, eiving lllin of extra usable cabin length. The 800 was essentially a 700D with increased payloadcapacity for ootimum economy on the shorter stages. B.E.A.'s fleet of 24 802s is now at full strength, havine entered service in Februa'V1957. Like the 700D, the 800 is powered by Dart 510s. Gross weight is 63.000 lb. Other operators of Viscount 800s are Aer Lingus, Trans-air, K.L.M. and in the near future N.Z.N.A.C. and Eagle. From the 800 stemmed the hieher-powered 806, sixteen of whichB.E.A. are now taking delivery. This was an intermediate step to the Viscount 810/840 described in the preceding pages.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
