Hawker Cygnet

В ответ на объявленный Министерством авиации конкурс легких аэропланов, который должен был состояться в сентябре 1924 года в Лимпне, Кент, фирма "H.G. Hawker Engineering Company" разработала и построила два экземпляра легкого самолета под обозначением Hawker ДальшеMore>>> Cygnet. Самолет представлял собой биплан деревянной конструкции с полотняной обшивкой с зависающими элеронами вдоль всей задней кромки верхнего крыла, обычным оперением и шасси с хвостовым костылем. Один самолет (G-EBMB) был оснащен двигателем British Anzani мощностью 34 л. с. (25 кВт), а второй (G-EBJH) - ABC Scorpion такой же мощности. Призовые места на конкурсе 1924 года занять не удалось. Лишь в 1926 году, оснащенный мотором Bristol Cherub III, самолет G-EBMB выиграл приз газеты "Дейли Мейл" в 3000 фунтов, а самолет G-EBJH стал первым в открытых гонках с гандикапом.


ТАКТИКО-ТЕХНИЧЕСКИЕ ХАРАКТЕРИСТИКИ

   Hawker Cygnet

   Тип: двухместный легкий спортивный самолет
   Силовая установка: один ПД Bristol Cherub III мощностью 34 л. с. (25 кВт)
   Летные характеристики: максимальная скорость у земли 132 км/ч; потолок 2715 м
   Масса: пустого 169 кг; максимальная взлетная 431 кг
   Размеры: размах крыла 8,53 м; длина 6,22 м; высота 1,78 м; площадь крыльев 15,33 м2

Flight, September 1924

THE SOPWITH-HAWKER LIGHT BIPLANES (Nos. 14 AND 15)
A.B.C. "Scorpion" and Anzani Engines

   As the first light 'plane to be designed and built by the H. G. Hawker Engineering Co., Ltd., of Kingston-on-Thames, considerable interest attaches to the two machines that have been entered by this firm for the Lympne competitions. The old Sopwith firm had a reputation for light construction, and it is significant that the same characteristics are to be found in the two light biplanes. So much is this the case that the two Hawker machines will be the lightest of all those taking part in the competitions. The weight empty - i.e., complete with engine, but without pilot, passenger, petrol and oil - is only 373 lbs. Assuming that the engine weighs roughly 100 lbs., the machine itself weighs only about 270 lbs., which is extraordinarily light. How this very low figure for structure weight has been attained will, it is hoped, emerge from the following description. That it is the result of the most painstaking work in detail design will be obvious, and literally not one ounce of unnecessary weight has been allowed to remain in the structure. The total loaded weight is only 730 lbs. As to the outward appearance, this is shown in the general arrangement drawings and photograph given herewith, and it will be seen that the machine is, for a biplane, of extremely pleasing and graceful lines.
   The machine is a staggered biplane, with large gap and very small bottom plane. The wing section used is a "thin" one with very high value of L/D maximum, and as the design is very clean the Hawker biplane should have a very good performance as regards top speed. With the light wing loading, and the wing flap gear increasing the maximum lift coefficient, the slow-speed should be very low, so that a very good speed-range figure should be attained.
   Structurally, the Hawker machines, which are identical, except that one will have an A.B.C. "Scorpion" and the other an Anzani engine, are of interest on account of the exceedingly careful detail design. The fuselage is a girder consisting of four longerons spindled out to an X-section and braced in the form of a Warren truss by diagonal struts of the same section. The struts are attached to the longerons by three-ply gussets partly riveted through and partly screwed, the joint being shown in Fig. 3 of the accompanying sketches. Thus there must have been a considerable saving in weight owing to the absence of metal fittings, while there is no risk of distortion requiring subsequent trueing-up. The sides and bottom are flat, while the deck is cambered, built up of wedge-section stringers on three-ply formers as shown in the sketch. The side panels, over the portion between the two cockpits, are braced by tie rods. The covering is fabric.
   The biplane wings, of which the top 'plane has a chord of 4 ft. 3 ins. and the bottom plane 2 ft. 6 ins., are built on box spars of normal construction, over which are fitted the spruce ribs, the latter being of Warren truss construction similar to the fuselage, except that the flanges and ties are of square (i.e., not spindled out) section. The box spars are wrapped in fabric. The top centre-section is carried on four steel struts with wood fairings, while the bottom plane is attached to short wing roots built into, or rather underneath, the fuselage, as shown in sketches 1 and 2. Provision is made for folding the wings, a light jury strut being fitted between upper and lower front spars. The inter-plane struts are of spruce, and are of the "I" type. They have a considerable outward rake.
   In order to gain a little on the low-speed, variable camber wing flaps are fitted - i.e., the ailerons run the whole length of the wing and are pulled down together, while still retaining their differential action, by so arranging the longitudinal rocking shaft that it is hinged at its forward end, while the rear end can be raised and lowered by a small worm gear. In raising this shaft the lower cables are pulled in while the upper are paid out, the flaps thus being pulled down.
   The undercarriage is of the simple vee type, with plain rubber cord shock absorbers.
   The tail consists of tail plane, elevator and balanced rudder.
   The A.B.C. and Anzani engines are mounted on very light supports in the nose of the fuselage, and the petrol and oil tanks are carried in the deck fairing behind the engine bulkhead.
   The workmanship put into the Hawker light 'planes is of a very high order of excellence, and, barring accidents, the machines should do well in the competitions. They will be piloted by two of the best pilots it has been possible to find - i.e., Raynham and Longton, both of whom, in addition to being pilots of vast experience, have done a considerable amount of flying on light 'planes.

Flight, September 1926

British Light ‘Plane Development & Lympne Meeting

THE 1926 MACHINES

No. 4. The Farnborough "Cygnet." (Bristol "Cherub" Engine.)

   This machine is practically identical with the Hawker "Cygnet" entered by Messrs. Sopwith and Sigrist, by whom, it may be recollected, it was presented some time ago to the Royal Aircraft Establishment Aero Club. It is thought that it may have a slightly lower weight than the Hawker "Cygnet" owing to the fact that the latter has been somewhat strengthened in order to earn a slightly greater useful load. No accurate figures are, however, available.


No. 6. The Hawker "Cygnet II." (Bristol "Cherub" Engine.)

   Designed in 1924 for the Lympne light 'plane competition of that year, and having won the International Handicap at the August Bank Holiday meeting of 1925 at Lympne, this machine is already familiar to our readers. It may be recollected that in the 1924 meeting it was the machine with the lowest structure weight, and that but for the failure of its engine on the last lap it might well have beaten the Beardmore "Wee Bee." That the "Cygnet" is a very efficient aeroplane, aerodynamically as well as structurally, cannot be doubted. This year it has been fitted with a Bristol "Cherub" Series III engine, and the structure has been strengthened in one or two places so as to obtain an airworthiness certificate for a somewhat greater total loaded weight. The reason for this is that it was desired to carry slightly more than the 340 lbs. useful load stipulated as a minimum. We believe that the C. of A. covers a total loaded weight of 840 lbs., but actually the useful load carried will probably be only 360 lbs., giving a loaded weight of 822 1b. Like many other competitors, the "Cygnet" is faced with the problem of clearing the 25 ft. barriers in 300 yards with full load, which may not be any very easy matter, and, in fact, may easily eliminate more than one competitor, or at any rate prevent them from flying in the competition with as great a useful load as is covered by the C. of A.