Flight, May 1922

THE VICKERS "VULCAN" EIGHT-PASSENGER COMMERCIAL BIPLANE
360 H.P. Rolls-Royce "Eagle VIII" Engine

   AT the Weybridge works of Messrs. Vickers, Ltd., a new commercial aeroplane is nearing completion; in fact, by the time these notes appear, the first machine of the "Vulcan" class will probably have been put through its preliminary tests by Capt. Cockerell. As distinct from recent Vickers land machines of Mr. R. K. Pierson's design, the "Vulcan" is a single-engined biplane, although retaining in other respects many of the features which distinguish Vickers machines.
   At the time of our visit to the works, the first of the "Vulcans" was not completed, and it has not, therefore, been possible to include in this description photographs of the machine. The scale drawings on p. 254, will, however, give a very good idea of the general lay-out. The first feature which one notices is the unusual depth of the fuselage, which extends right up to and serves as a support for the top plane. One result of this great depth is that in side view the fuselage looks somewhat stumpy, although the streamlining is uncommonly good. The width of the fuselage is not, of course, nearly so great, as will be seen from the plan view, and the resistance of the fuselage, is probably very low.

General Design

   Although of considerable span - 49 ft. - there is only one pair of interplane struts on each side. This reduction in the wing bracing has been made possible by the adoption of a thick section, high-lift wing. The actual section employed is one of the airscrew sections, No. 62, we believe, with flat bottom camber. The space available for spars is, therefore, considerable, and the long bays are further relieved by building up the wings as continuous beams. In the drawing, it will be noticed that the wing roots, both top and bottom, extend some distance out from the fuselage. The reason for this arrangement is that the joint between spar root and inner end of end section spar occurs at the point of contraflexure, where the bending moment is zero, and where, consequently, the fish plates of the joint have to resist shear only.
   As regards general design, the "Vulcan" is a relatively low-powered weight-carrying commercial machine, in which economy in manufacture and operation have been given precedence over performance. Every endeavour has been made to make the "Vulcan" a truly commercial machine, and if it is not quite so fast as some modern commercial machines, it possesses other features which, in our opinion, more than outweigh the relatively low cruising speed of 90 m.p.h. To begin with, the machine carries eight passengers on one Rolls-Royce engine of 360 h.p., so that the power expenditure is only 45 h.p. per passenger at full power, and a maximum speed of about 105 m.p.h. This should certainly bring the machine within sight of being able to show a profit without the aid of a Government subsidy. Furthermore, the low landing speed (about 40 m.p.h. on estimated figures) should make for safety, and should also enable the machine to get out of quite small fields. It is also possible that for a machine which lands so slowly, a lower insurance premium might be required, all of which are points in favour of the lightly-loaded and relatively slow commercial aeroplane.
<...>

The Cabin

   It has already been mentioned that the cabin has seating accommodation for eight passengers. The seats are of a special type designed by Vickers, and when not in use fold up against the sides of the cabin. The back rest folds forward on to the seat, and the whole then turns on longitudinal hinges, folding upwards and outwards, as shown in two of our sketches. Should it be desired to use the machine for carrying goods, the seats may be easily removed, each being held in place by two bolts only.
   A feature of the cabin is the great amount of head-room, about 8 ft. This results from the monocoque construction and the elliptical cross section of the fuselage. In front this head-room is somewhat smaller, owing to the projection of the pilot's cockpit into the front part of the cabin. At the rear a smaller portion is cut off by a locker or luggage space in the roof, but there is still plenty of room for even a tall man to stand upright.
   In the front wall of the cabin there is a small door on each side, through which the pilot may communicate information to the passengers. Between the two doors is a narrow panel enclosing the two vertical tubes of the aileron control. The top of this panel is left open so that the attachment of the tubes to the cranks is always exposed and easily accessible for adjustment. Incidentally, a passenger who knows something about flying may, by watching theses tubes, get an idea of the amount of use being made of the ailerons.
   Behind the cabin, and separated from it by a transverse bulkhead, is a compartment divided into two. That on the port side is a diminutive lavatory, while on the starboard side is the luggage compartment. The latter is divided into two "stories," the upper of which is reached from the cabin through a door in the rear wall, and evidently meant for "wanted during the journey" luggage. The lower luggage compartment, which has a portion projecting forward under the double seat on the starboard side, is reached through a door in the starboard side of the fuselage.
   By the time this issue of FLIGHT is distributed, the first of the "Vulcans" should have been in the air on its preliminary tests. It will then, probably, go to Martlesham for type tests, and should be on the London-Paris service (Instone Air Line) in a couple of weeks. The main characteristics of the "Vulcan" are as follows: Engine, Rolls-Royce "Eagle VIII"; length of machine o.a., 37 ft. 6 ins.; height o.a., 14 ft. 3 ins.; span, 49 ft.; chord, 9 ft. 3 ins.; maximum gap, 8 ft.; area of main planes, 840 sq. ft.; wing loading, 7.3 lbs./sq. ft.; power loading, 17 lbs./h.p.; weight of machine empty, 3,775 lbs. (pilot, 180 lbs.); 72 gallons of petrol, 510 lbs.; 5 gallons of oil, 45 lbs.; reserve water (2 gallons), 20 lbs.; W/T, 100 lbs.; eight passengers at 160 lbs., 1,280 lbs.; luggage or freight, 240 lbs.; total loaded weight, 6,150 lbs. Maximum speed near ground (estimated) 105 m.p.h. Cruising speed (estimated) 90 m.p.h. Landing speed (estimated) 40 m.p.h. Climb to 6,000 ft. (estimated) 14 mins.