M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
P.Lewis British Aircraft 1809-1914 (Putnam)
Among the most successful of the early monoplanes was the Dyott, at the same time one of the neatest-looking of the practical aeroplanes of the period. The elegant little 50 h.p. Gnome-engined machine took its name from that of its owner. G. M. Dyott, to whose specification it was made. Its originator, who gained his Royal Aero Club Aviator's Certificate No. 114 on 17th August, 1911, on a Bleriot at Hendon, decided during the following year to construct a machine of his own design for cross-country flying. The work was entrusted to the Hewlett and Blondeau Company, the aircraft being built in their works at Clapham and completed early in 1913.
After successful test flights, the Dyott monoplane was taken without delay by its owner on an extensive six-months tour of the U.S.A. From April, 1913, until the following October, the machine flew for some 2.000 miles, giving exhibition flights as far West as California. Reports reaching Britain from George Dyott were most enthusiastic about its reliability and lively performance. Writing from New York he claimed that it went "like a rocket", was taking off in 40 yds., and was reaching a top speed of 75 m.p.h.
In November, 1913, the Dyott was flying again at Hendon and was entered in the London-to-Brighton Handicap, which was flown on the 8th of the month. Starting from Hendon, the nine British, French and American entrants had first to fly to Harrow Church and then set course for the Palace Pier at Brighton, the finishing-point for the first half of the contest. After flying westwards along the coast, they were to land at Shoreham, refuel and fly back to the Palace Pier, there to continue the race home to Hendon. The powerful wind blowing at the time from the West caused a miscalculation in drift, carrying the Dyott over Eastbourne, where a landing was made on Beachy Head. The machine alighted successfully, but was unfortunate enough to be blown over on to its back by a gust, leaving no option but withdrawal from the race. A projected flight to be made to India with the aircraft did not finally materialize.
Features of the Dyott were the mid-wing and the lack of ailerons, lateral control being effected by warping of the tips. One rather undesirable aspect of the design was that the flying wires were attached direct to the undercarriage, thus subjecting the wings to the strain of landing loads. In addition to the usual flight instruments of tachometer, oil gauge, compass, petrol gauge and altimeter, the cockpit contained a special graphic recorder, designed by George Dyott, which noted by means of three pointers on a revolving drum the different movements of the controls for elevators, rudder and warping. Replacement of parts of the airframe was facilitated by a system of joining the components together with nuts and bolts. In addition to the 8 galls, oil and the main 8 galls, petrol tanks, an auxiliary of 10 galls, petrol was carried behind the pilot, giving enough fuel for 3 hrs. duration.
Description: Single-seat mid-wing tractor sporting monoplane. Wooden structure, fabric covered.
Manufacturers: Hewlett and Blondeau Ltd., Omnia Works, Clapham Junction, London. S.W.
Power Plant: 50 h.p. Gnome.
Dimensions: Span, 29 ft. Length, 23 ft. Wing area, 148 sq. ft.
Performance: Maximum speed, 75 m.p.h. Landing speed, 45 m.p.h. Endurance, 3 hrs.
Flight, April 26, 1913.
THE DYOTT MONOPLANE.
A VERY interesting machine has just been completed at the Hewlett and Blondeau Aeroplane Works at Clapham, to the designs of Mr. G. M. Dyott. Although in its outward appearance the machine follows the lines of well-known makes, Mr. Dyott has managed to incorporate in it a very great number of cleverly-thought-out details, which his practical experience as a pilot has suggested to him.
The fundamental feature of the design of this machine is the fact that the gunwales are parallel to the line of flight, a method of construction which greatly facilitates the "tuning up" of the machine, as all adjustments may then be made from this line. This is a point which will be readily appreciated by anybody who has ever had to tune up a machine on the flying ground or in a temporary hangar, the floor of which was not level.
The body, which is of rectangular section, is built up in the usual way of four longerons connected by struts and cross members, the whole being braced by strong diagonal wiring. Ash is the material used in the construction of the front part of the body, where it has to carry the weight of the engine, tanks and pilot, and where consequently the greatest strength is required, while the rear portion of the fuselage is made of spruce. It is interesting to note that the joints of the struts and cross members to the longerons are so designed that not a single nut projects beyond the fuselage, a fact which permits the fabric to be applied absolutely smoothly to the body. From a point just behind the pilot's seat thin streamers, forming a "turtle back," run back to the rudder post, thus forming a nice stream-line. An aluminium cowl covering up the cockpit and front part of the body, and extended beyond the nose of the machine to form an oil-shield over the engine, completes the stream-line.
As will be seen from the plan view of the machine, the wings, which are somewhat reminiscent of the Dep., have two main spars of rectangular section, each spar being built up of three laminations, ash in the centre and spruce on the sides. Both spars fit into sockets situated in two stout transverse struts in the fuselage. In order to allow of the wings being warped, the socket for the rear spar is made a loose fit on the spar, which is pivoted around a strong bolt, secured by a split pin. To dismantle the wings, all that is necessary is to undo the top and bottom stay wires and the two bolts through the rear spars, and the wings can be taken off. The ribs, which are evenly spaced along the spars, are built up of webs of ash with flanges of spruce. The wings, as well as the body, are covered with unbleached linen, doped with S.P.L.A. varnish, the fabric being laced along the trailing edge, so that it may be kept taut under all climatic conditions. Lift and drift are taken by stout stranded cables attached to the lower extremities of the front skid struts, whilst the top bracing is effected by cables secured to a tubular A-shaped pylon. This pylon fits into two sockets on the gunwales, and is braced fore and aft by steel wires. By undoing these wires the pylon may be pulled out of its sockets and stowed away inside the body. The lower pylon, which consists of a single stream-line tube, carrying at its lower extremity a drum for the warping cable, is pivoted to the floor of the fuselage and stayed fore and aft by steel wire, so that it may be folded flat against the body.
Situated well down in the deepest part of the body, so that only the pilot's head projects above the cowl, is the pilot's seat, which is made of welded steel tubing and slung from the gunwales and securely braced to the lower longerons by steel wires. A neat padding of red leather, strapped on, covers the tubular framework of the seat, and the edges of the cockpit are padded in a similar way to protect the pilot, should he be thrown against them owing to a rough landing.
In front of the pilot is a very neatly-designed dashboard with all the different instruments useful for cross-country work, nearly all of which have been specially made for Mr. Dyott. Thus the compass, which is made by Kelvin and James White, Ltd., has only the cardinal points N.S.E.W. marked on it, and the four divisions are painted white, yellow, blue and red respectively. The pilot does not watch the compass card directly, but its reflection in a small mirror seen in one of the accompanying sketches. The north quadrant is painted white, and so the pilot knows that as long as he sees white in the mirror, he is steering a course somewhere between the quadrantal points N.W. and N.E. This does not, of course, give very accurate steering, but Mr. Dyott finds that it is very difficult to keep an aeroplane absolutely on its course in anything but a dead calm, and so prefers this method.
In addition to the usual instruments carried, i.e., revolution indicator and altimeter, this machine is fitted with an instrument of Mr. Dyott's own invention. It is a graphic recorder which shows all the different movements of the control levers. The chart is divided into three parts: Warp, Elevator and Rudder. As the drum revolves, three pointers draw the three different graphs, so that in a straight flight, during which the control levers were not moved at all, the pointers would draw three straight lines, but as soon as the course was altered the pointer connected to the rudder would make a wavy line, and as the warp is used in conjunction with the rudder, the warp pointer would draw a corresponding curve. This instrument should prove of great service, and furnish some very interesting data for comparing the different ways in which different pilots control the same machine.
The method of controlling the machine forms the subject of one of our sketches, which explains it better than a mere description ever could. It will be seen that crossing of the elevator-wires is avoided, so that there is no danger of them rubbing against one another and so becoming frayed and ultimately worn through.
Coming now to the chassis, which is of the wheel and skid type, this structure is interesting, mainly on account of the ease with which its different members may be replaced in case of breakage. By undoing the bracing-wires, all the struts may be pulled out of their respective sockets (the front pair of which are welded to the engine frame) without unscrewing any nuts or screws.
This is one of the really useful features of the machine. The use of screws and bolts has been reduced to a minimum, and wherever possible one bolt has been made to serve two purposes. Thus only four bolts are employed to secure the tail plane, which is of the non lifting type, to the fuselage.
A framework of steel tubing forms the empennage, which is very strong and quite light - about 10 lbs.
Right outside the nose of the machine, where it is easily accessible, is mounted the 50-h.p. Gnome engine, which has no support between the engine and the propeller. Inside the body, and just behind the engine, are situated the oil and petrol tanks, which have a capacity of 8 gallons each. Just behind the pilot's seat is another petrol tank, containing an additional supply of 10 gallons. The petrol is forced from this tank to the one in the nose of the machine by means of a hand-pump, situated to the left of the pilot's seat.
Mr. Dyott is taking this machine out to America, where he is booked to give exhibition flights in California, and at other places. We understand that on a similar machine Mr. Dyott proposes, on his return from America next October, to attempt the flight to India, the arrangements for which are now being made by Mr E. Esdaile.
Flight, May 24, 1913.
THE DYOTT MONOPLANE.
FROM Mr. G. M. Dyott, writing from New York on the 9th, comes some interesting news regarding this new machine, which was illustrated in FLIGHT on April 26th. He writes as follows: "The performance of my machine has surprised everyone, and its construction meets with universal admiration.
"She goes like a rocket, 75 miles an hour, with a 50-h.p. Gnome. The minute the tail is let go it leaves the ground at once, and the whole machine shoots forward at a tremendous speed; at 40 yards she is off the ground and climbing fast, with tail well up, not dragging at all, which is the ideal.
"Of course, the quick starting was one of the main objects of the design, but even I am surprised at her speed, and the way she hops off the ground at 40 yards.
"The machine handles well, and it is a joy to sit in the seat as comfortably as in an armchair, with not a breath of wind in one's eyes, at a speed of 75 miles.
"The field of vision is very fine, and at the same time the pilot can sit down inside if he likes, and neither see nor be seen. Every one at the Field is talking about it; so, on the whole, I am very pleased."
Flight, November 1, 1913.
THE DYOTT MONOPLANE AT HENDON.
AFTER an extensive tour of the U.S.A., where he has given numerous exhibition flights, Mr. G. M. Dyott has brought his machine back to this country, and it is now flying at Hendon. When looking at this machine it is difficult to believe that it has just completed a series of exhibition flights, most of them made under anything but ideal conditions, so well has it kept its ship-shape appearance. Not only has it flown one 2,000 miles, but on two occasions the machine was turned upside down when landing without breaking anything of importance, thus testifying to the qualities of the design and the workmanship.
With the exception of one or two details the machine is not altered since its completion in April this year, on which occasion it will be remembered it was fully described in the columns of FLIGHT. One of the alterations is to the tail skid, which has been replaced by one of cane instead of the long wooden skid with which it was fitted when Mr. Dyott took the machine out to America. Another alteration has been made to the mounting of the transverse steel tube which connects the two skids of the chassis. Instead of securing this tube to the lower extremity of the strut, which method involved a special socket, it is now fitted in a plain socket on the skid and working in compression only, the tension being taken by two stranded cables running parallel with the tube. Should the tube become damaged it can, if necessary, be replaced with a piece of gas pipe, as the socket can be made of the simplest form. The machine is particularly well equipped with all the usual instruments for cross-country work, and is in addition fitted with an instrument for recording the movements of the control levers by means of three pencils which are connected to the warp, rudder and elevator respectively.
We hope shortly to be able to publish a description of this recorder together with some graphs specially prepared for FLIGHT by Mr. Dyott.
From what we have seen of it the machine appears to fulfil admirably the conditions for which it was designed. It has light weight combined with strength, it can be easily dismantled and erected, it has a good climbing speed, on landing it pulls up very quickly and it can land in a small field, as the minimum speed is fairly low.
The upper and lower pylons can be removed by undoing a few wire strainers, and similarly that is all that is necessary to dismantle the chassis, since the struts are a sliding fit in their sockets, and can be pulled out when the diagonal cross wires have been removed by undoing the turnbuckles. The accompanying photograph shows the aluminium covering on the front part of the fuselage removed, an operation which only takes about a minute, and which allows the closest inspection of the engine and controls.
The maximum speed of the machine is about 65 m.p.h., while it can be landed at a speed of about 45 m.p.h. The tanks contain enough fuel for a three hours flight with the 50 h.p. Gnome engine with which it is fitted.
Flight, October 22, 1915.
The two examples given of the single axle and single-pairs-of wheels form of undercarriage are similar in type and differ in detail construction only. In the Dyott monoplane the axle runs right across from skid to skid, while in the Sopwith Scout the stub axles are pivoted in the centre, half way between the skids, and move up and down between two transverse members. Bracing of the front portion of the undercarriage is effected in the Dyott machine by a transverse compression member and diagonal cross-bracing, while in the Sopwith there is no such transverse member in front, its place being taken by cables running outwards from the skids to the main planes.