Flight, September 1924

THE WESTLAND "WIDGEON" LIGHT MONOPLANE (No. 6)
Blackburne Radial Engine

   THE West land monoplane, the "Widgeon," is of very unorthodox design compared with the majority of the machines entered for the Lympne competitions, not only as regards its aerodynamic features, but also in the matter of structural design. It is regretted that no photographs of this machine are available, but the general arrangement drawings should give a fairly good idea of the lines, while the unusual wing spar construction is shown by a sketch (Fig. 5.)
   The Westland "Widgeon" is a "parasol" monoplane - i.e., with the wing placed well above the fuselage. The view laterally, forward and aft, and downwards should be well-nigh perfect, while even in an upward direction the view is restricted to but a very small extent. This is due to the fact that the monoplane wing tapers considerably in chord towards the root, so that the pilot in the rear cockpit can look up and backward, while the front pilot can look in all directions, except diagonally up and back.
   The fuselage structure is almost identical with that of the Westland "Wood Pigeon" - i.e., a ,normal girder braced by piano wire tightened by turnbuckles. It is flat-sided and flat-bottomed, but with cambered deck. The engine shown in the general arrangement drawings is a Bristol "Cherub," but actually we believe a Blackburne will be fitted.
   The monoplane wing is tapered in chord and thickness from the strut attachments to both root and tip. The folding arrangement is very similar to that described in detail for the biplane, except that the two front external struts are taken to the inner end of the lift struts. As in the biplane the ailerons run the whole length of the wing, and they are of unusual plan form in order to continue the aerofoil sections of the tapering wing.
   Structurally, the wings are of interest on account of the unusual spar construction. In place of I section or box section spars, those of the Westland "Widgeon" are built up as shown in Fig. 5. The central spar web is of three-ply wood, cut out to form a series of X's. Top and bottom flanges are screwed and glued to each side of this three-ply web, while the three-ply itself is reinforced by diagonal strips, the divided strips on one side coming opposite the solid strip on the opposite side. The sketch will make this point clear

Flight, July 1927

THE WESTLAND "WIDGEON III"
"Cirrus II" or "Genet II" Engine

   THE old controversy - biplane or monoplane - has by no means been settled yet, and it is only to be expected that in the light 'plane class the fight will go on for some time, the more so as it is now becoming realised that there is very little to choose between the two types. There is, however, this difference - that whereas in the earlier days of aviation the dispute centred mainly on aerodynamic efficiency, in modern times, and especially since the Lanchester-Prandtl aerofoil theory became generally accepted, it has become clear that from the point of view of aerodynamic efficiency the two types are so nearly equal that there is no valid reason for believing that on this score one type will ever entirely bust the other. Thus, from the point of view of induced drag, the biplane is, for a given span, more efficient than the monoplane, but maximum lift coefficient is slightly greater for the monoplane than for the biplane. As regards profile drag, the monoplane will, generally speaking, require a slightly thicker wing section to give an economical wing weight, and it is usually found that with biplanes of normal arrangement the gain in profile drag obtained by the use of the thinner aerofoil which the biplane arrangement permits is approximately balanced by the drag of the external bracing of the biplane, and so we arrive at practically a "dead heat" between the two types as far as aerodynamic efficiency is concerned.
   There still remains what may be termed the "practical" side of the question, and here there is scope for the designer's personal views. The biplane may perhaps be said to score on account of smaller overall dimensions, which affect the question of housing, and consequently we see some designers choose the biplane as being the more compact type. On the other hand, it is possible so to arrange the monoplane that the overall dimensions do not greatly exceed those of a biplane of the same weight, while at the same time gaining certain not inconsiderable advantages, such as unrestricted view from the pilot's cockpit, ease of access to both cockpits of a two-seater, and so forth. Thus, in asking oneself the question why this or that designer has chosen one or the other of the two types, it is usually into the practical considerations that one should look for an answer. In this country we may almost be said to have specialised on the biplane. Probably more than 95 per cent, of all British machines built during the last 10 years have been of the biplane type. In Germany, on the other hand, the monoplane has been the more popular type, although there appears of recent years to be a tendency to change over to the biplane. France has divided her attentions more or less equally between the two types.
   When, amid the number of biplanes in this country, a monoplane type appears, there is thus bound to be speculation as to the reasons which led to the choice of the more unusual machine. In the case of the Westland "Widgeon III," which forms the subject of this descriptive article, we believe that practical rather than aerodynamic considerations led to the decision to market a monoplane, and by choosing the parasol type of monoplane the Westland Aircraft Works of Yeovil claim to have attained certain very practical advantages. For instance, the placing of the wing some distance above the fuselage provides an all-round view which would not be possible in a biplane. Downwards, to the sides, forward and aft, there is nothing but the fuselage to hinder the view. Placed as he is some distance aft of the wing, the pilot can look in all directions except diagonally, forwards and upwards, and even here, owing to the angle between the wing and the line of vision, only a very small area is obscured by the wing, which is, in fact, seen by the pilot almost "edge on." The passenger is situated immediately below the wing, and thus cannot see upwards, but otherwise he (or she) also has an unobstructed view. Moreover, the parasol arrangement greatly facilitates access to the cockpits, the aft, or pilot's, being clear of the cut-out in the wing, and the front one being reached through a small door, much as one enters a motor-car. The fact that the wing is strut-braced makes for a minimum of encumbrances, and the front seat is reached entirely without the acrobatic feats required in some machines.
   The strut bracing of the "Widgeon" wing is also claimed to reduce maintenance cost, since there are no wires whatever in the machine, other than control cables, to require attention. Once in place on the machine, the wing bracing is not touched except in case of damage, and the wing will, it is claimed, remain true without any attention from the user. The arrangement of the wing struts of the "Widgeon" is such that folding the wings is an extremely easy operation, all that is necessary being the release of two pins, one on each side, when the two halves of the wing are free to swing back along the tail. The aileron cables are so arranged that as the wings fold back the return cable goes slack, allowing the ailerons to hang down, and thereby reducing the folded width of the machine, which in the folded condition is only 10 ft. 6 in.
   Thus the main features of the "Widgeon III" of interest to the owner-pilot may be summed up as follows: excellence of view, ease of access to cockpits absence of wire bracing, with consequent reduction in maintenance cost and work, and general simplicity of construction. This summary does not, however, by any means exhaust the features of the machine, as the following descriptive notes on the construction will show.

Constructional Features

   It has already been pointed out that simplicity of construction is one of the objects aimed at in the "Widgeon III." This the fuselage is of the type in which there is no wire bracing, the inner framework being covered and partly braced by the three-ply "skin." From the fact that three-ply is used for covering it will be gathered that the fuselage is flat-sided and flat-bottomed. The deck, however, is of the usual curved or cambered shape, made up in panels or sections, and supported internally by hoops or formers. Experience has shown this type of fuselage construction to be rigid, capable of standing hard wear, and requiring a minimum of attention during use. A fabric covering on top of the three-ply protects it against moisture.
   The cockpits, as already stated, are very easy of access, and are in addition roomy and comfortable. Dual controls are provided, so that the machine may be flown from either cockpit, or the front controls may be disconnected if the machine is being used for passenger work only. The instruments, which include the usual range, are very neatly arranged and the various dials are easily seen. The seats are somewhat unusual in that they are separate from their back rests. Normally, fairly high seats, of light ply-wood construction, are fitted, and provided with air cushions. Should the owner prefer to fly regularly with a pack parachute, the seats are changed as slightly lower ones on which the parachute pack rests, the seat frameworks of the two types of seat being so proportioned that the overall height is the same in both cases.
   Between the two cockpits, in the deck fairing, is a luggage compartment with a separate door, while in front of the forward cockpit is another and slightly smaller luggage space. Thus it is quite feasible to go touring on the "Widgeon III" and take sufficient luggage for ordinary requirements. The front cockpit is provided with a door on the starboard side, and as a small steel tube step is fitted to the lower longeron, underneath the door, one can step into this cockpit without any climbing whatever.

The Wing.

   The wing construction is of the perfectly straightforward type, with wooden box spars, spruce ribs and fabric covering. The ailerons, which run over the whole span of the wing, are of narrow chord, being hinged to an auxiliary spar, and are thus of high aspect ratio and claimed to be very effective while working very easily and with small forces on the control stick. They are operated by short cables running through the sides of the fuselage, the control crank being situated at the inner end of the aileron. Constructionally, the ailerons differ from the wings in being of metal construction, as are also all the tail surfaces. Duralumin and aluminium are the materials used, the tubular spar or leading edge of the ailerons being Duralumin, and the ribs of sheet aluminium. The wing section used is R.A.F.34.
   The wings hinge on the points of attachment of the rear spars to the centre section, and with the steel tube wing bracing employed, which is very rigid, no "jury struts" are required unless the machine is to be transported over long distances. The centre section of the wing contains the petrol tank, the high position enabling direct gravity feed to be employed, with consequent simplification of the petrol system. An extension handle pointing back from the tank enables the pilot to turn the petrol on or off from his seat. The petrol capacity is 15 gallons, and as the machine does an average of 20 miles per gallon, the range is about 300 miles.

Undercarriage

   The undercarriage of the "Widgeon III" is of special type. The telescopic rear "legs" are of oval section steel tube. The load is taken by stout coil springs of steel, and bouncing is prevented by interposing between the two portions of the telescopic “legs" Ferrodo dampers. This type of undercarriage is claimed to be particularly durable and robust, there being no rubber to perish, no air pressure to maintain, no glands to need attention.

Engine Installation

   The engine installation in the "Widgeon III" is particularly interesting, and has been so planned that the whole engine unit can be removed after undoing four bolts, and, of course, the usual petrol leads, engine controls, &c. The engine bed is of welded steel tubing, and two types have been standardised, one of which takes the "Cirrus II" engine and the other the Armstrong-Whitworth "Genet II." Owing to the difference in weight between the two engines, the centre of gravity would be slightly displaced by the substitution of one for the other. To counteract this, the Westland Aircraft Works employ the neat arrangement of standardising two centre-sections, one of which gives a slightly greater sweep-back to the wings than the other.

Load Factors

   The Westland "Widgeon III" has been designed to give the required load factors for the British Air Ministry's "Aerobatic" Airworthiness Certificate with a total loaded weight of 1,400 lbs., and for normal flying the factors cover a loaded weight up to 1,600 lbs.

Specification

   The main dimensions and areas are shown on the general arrangement drawings. Following are the main characteristics of the machine: Weight empty ("Cirrus II") 852 lbs.; ("Genet") 775 lbs. These figures are made up as follows: Wing, with bracing, centre-section, etc., 242 lbs.; tail, 30 lbs.; fuselage and engine mounting, 240 lbs.; power unit exclusive of tanks, 240 lbs. ("Genet"); 321 lbs. ("Cirrus"); total weight of power unit, inclusive of tanks, petrol (113 lbs.) and oil (15 lbs.), 391 lbs. ("Genet"); 468 lbs. ("Cirrus"). Pilot, passenger and luggage, 420 lbs. Total loaded weight, 1,323 lbs. ("Genet"), 1,400 lbs. ("Cirrus"). These figures refer to machine with wooden propeller. If Fairey-Reed metal propeller is fitted 14 lbs. should be added.
   As the machine has a wing area of 200 sq. ft., the wing loading is 7 lbs. sq. ft. with the "Cirrus" and 6-6 lbs. sq. ft. with the "Genet." The power loadings are 18-4 lbs./h.p. and 17-9 lbs./h.p. respectively.

Performance

   Following are the performances of the "Widgeon III": Top speed, 100 m.p.h.; cruising speed 85-90 m.p.h.; minimum speed, 42 m.p.h.; initial rate of climb, 560 ft./min. service ceiling, 14,000 ft.; climb to 5,000 ft. in 11 mins.; to 10,000 ft. in 27 mins. 40 secs.

Flight, March 1929

THE WESTLAND "WIDGEON IIIA"
A.D.C. "Cirrus III" or D.H. "Gipsy" Engines

   AS a result of the experience gained by the Westland Aircraft Works with their "Widgeons" Mark I, II and III, a modified version is being produced for 1929, which incorporates a number of improvements, chief among which is, perhaps, the introduction of a new type of undercarriage. The high-wing type of monoplane requires rather a wide-track undercarriage if ample stability on the ground is to be attained, and recent tests at Yeovil indicate that this has been achieved by the new design, in which the "crossed-axle" arrangement has been adopted. In this, the port axle (which is of the bent type) is hinged to the lower longeron on the starboard side and vice versa. One advantage of this arrangement is that the angle of the axle is reduced, the sharpness of the bend is also lessened, and most important of all, the axle itself is lengthened, with the result that for a given wheel travel (vertical), the change of lateral angle of the wheel is reduced. Thus a long travel can be provided without the wheel assuming "bow legged" angles with the load off the undercarriage and "knock-kneed" angles with the full landing load on the wheels.
   The telescopic "leg" of the new undercarriage is the same in general principle as that which has now been employed on Westland light 'planes for a number of years. The landing shock is taken on a strong steel coil spring, and bouncing is prevented by, as well as a certain proportion of the landing load taken on, a split sleeve with Ferrodo lining. As this split sleeve has adjusting bolts, the amount of friction can be varied to any required amount by tightening up the bolts. The wearing qualities of the Ferrodo lining are well known, and as there is no air pressure to maintain nor rubber to perish, the "leg" requires astonishingly little attention in service. An occasional greasing of the bearing points is all that is needed.
   As each half of the undercarriage consists of a three-legged pyramid, with one strut going to its own lower longeron, the axle to the opposite lower longeron, and the telescopic leg to the top longeron, the landing shocks are extremely well distributed, and it has been found that stall-landings can be made without damage to machine or undercarriage.
   Following the policy of making the "Widgeon" as near "fool-proof" as possible, experiments have been made with the Handley Page automatic wing tip slots, although it is claimed that even without them the "Widgeon," owing to its parasol wing arrangement and the wing section used, possesses many of the characteristics of the slotted wing in the stalled condition. As fitted on the "Widgeon" the auxiliary aerofoils of the slots are made of Duralumin sheet, bent to the contour of the nose of the main aerofoil. In the slot-closed condition, the auxiliary aerofoil rests snugly against the nose of the main section. The auxiliary aerofoil is attached by simple brackets and links, and supported near each end. A torque tube is incorporated in the system, and ensures the true alignment of the auxiliary aerofoil, as well as preventing it from twisting.
   Although not standardised, the "Widgeon" coupe will be available in the immediate future to owners desiring this type of weather protection. Experiments have been made which indicate that it is possible to add a coupe top to the cockpit without any sacrifice in performance. In fact, the initial flying tests rather tended to show that the enclosed machine was, if anything, a little bit faster than the open.

Dimensions

   The main dimensions of the “Widgeon III A" are as follows :-
   Length o.a. 23 ft. 5 1/4 in. (7-15 m.)
   Wing span 36 ft. 4 1/2 in. (11-1 m.)
   Wing chord 6 ft. 0 in. (1-83 m.)
   Wing area 200 sq. ft. (18-6 m.2)
   Width, folded 11 ft. 9 in. (3-58 m.)
   Height 8 ft. 0 in. (2-44 m.)
   Wheel track 7 ft. 0 in. (2-13m.)

Weights and Performances

   Weight of machine, empty 945 lbs. (430 kg.)
   Total load carried (Normal) 705 lbs. (320 kg.)
   Total load (Aerobatic category) 505 lbs. (230 kg.)
   Loaded weight (Normal) 1,650 lbs. (750 kg.)
   Loaded weight (Aerobatic) 1,450 lbs. (660 kg.)

   When the "Cirrus III" engine is fitted, the fuel capacity is sufficient for 3 hrs. 40 mins. at cruising speed. The machine takes off in about 100 yards and pulls up in about 60 yards. The "Cirrus III" gives an initial climb of 600 ft. per min. and a service ceiling of 15,000 ft. The climb to 5,000 ft. occupies 9 mins., and an altitude of 10,000 ft. is reached in 22 mins. The landing speed is about 42 m.p.h.
   An all-metal version of the "Widgeon" is now coming through the shops, and will be tested during the next few months. Details of its fuselage construction were published in FLIGHT of February 28, 1929. Recently, a Westland "Widgeon" has been' fitted with the A.B.C. "Hornet" engine, and flight tests are now in progress.

Flight, July 1929

BRITISH AIRCRAFT AT OLYMPIA

WESTLAND AIRCRAFT WORKS

   THE Westland Aircraft Works, which are a branch of Petters, Ltd., will be represented at Olympia by three complete aircraft and one "Wapiti" fuselage, shown in skeleton. The three machines will be: One "Wapiti" General Purpose two-seater, with Bristol Series VIII engine, one "Westland IV" three-engined limousine, with three "Hermes" engines, and one "Widgeon" Mark IIIA light monoplane with "Cirrus" Mark III engine.
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   The Westland "Widgeon" Mark IIIA is a light monoplane with "Cirrus III" engine, intended for the private owner, light 'plane club or flying school. At Olympia it is to be expected that the "Widgeon" will be very closely examined in view of the recent announcement that the Westland Aircraft Works are willing to sell the building rights, drawings, designs, etc., having decided to discontinue the building of "Widgeon" machines in the future in order to concentrate on the "Westland IV" type referred to above.
   The "Widgeon" is a parasol monoplane of mixed construction, with wings of wood and fuselage, ailerons and tail of metal. The Mark III A incorporates several improvements, such as the new type of split undercarriage, which has proved so effective in absorbing shock that stalled landings can be made without damaging the machine.
   The parasol wing arrangement is claimed to give a large degree of automatic stability, and the "Widgeon" can be flown stalled without falling into a spin. If desired, it can be fitted with Handley Page automatic wing tip slots. The accommodation is the usual found in light 'planes, with the cockpits in tandem and dual controls. The wings are designed to fold, and the machine then takes up but little room.
   The main dimensions of the "Widgeon" are: Length, o.a., 23 ft. 5 in.; wing span, 36 ft. 4 1/2 in.; height, 8 ft.; wing chord, 6 ft.; width folded, 11 ft. 9 in.; total wing area, 200 sq. ft.
   The tare weight of the "Widgeon" is 935 lbs. and the gross weight 1,650 lb. for "normal" certificate of airworthiness. For the "Aerobatics" C. of A. the maximum permissible gross weight is 1,450 lbs. The fuel capacity is of 20 gallons, giving a duration of 3 3/4 hours and a range of 315 miles. The full speed at ground level is 104 m.p.h. and the cruising speed 86 m.p.h. The service ceiling is 15,000 ft. and the rate of climb at ground level 640 ft./min.