de Havilland DH.53 Humming Bird
Первым сверхлегким самолетом фирмы "de Havilland" был DH.53 Humming Bird. Машину построили для конкурса авиеток на приз газеты "Daily Mail", состоявшегося в Лимпне, Кент, в октябре 1923 года.
Два небольших расчалочных моноплана оснастили мотоциклетными
моторами Douglas объемом 750 см'. Первый из них впервые взлетел в сентябре. Несмотря на значительные проблемы с мотором, оба самолета успешно прошли испытания.
Для повышения надежности на авиетки поставили моторы Blackburne Tomtit и немного их переделали. В 1923 году первая авиетка Humming Bird была представлена на выставке в Брюсселе. Позднее она приняла участие в нескольких авиагонках вместе со вторым аэропланом, принадлежавшим группе офицеров ВВС Британии. Офицеры заменили двигатель на мотор ABC Scorpion в 35 л.с. (26 кВт), оказавшийся ненадежным.
Благодаря экономичности первой авиетки Humming Bird Министерство авиации заказало восемь таких машин для связи и летной практики. Еще пять построили для гражданских заказчиков, три отправили в Австралию, одну в Чехословакию и одну в СССР. Две последние авиетки Humming Bird использовались британскими военными в экспериментах с запуском их с дирижабля R-33 и последующим причаливанием в воздухе. После списания всех восьми самолетов из ВВС в 1927 году, шесть из них перешли к частным владельцам и летали еще несколько лет. Один сохранился в запасах Фонда Шаттлуорта ("Shuttleworth Thrust") в Олд-Уордене, отремонтированный (с заменой ряда узлов) после Второй мировой войны. Он иногда совершал полеты, но в 1980-е годы дважды терпел аварии из-за поломок двигателя. Его вернули в летное состояние только в 2001 году.
de Havilland DH.53 Humming Bird
Тип: одноместный сверхлегкий самолет
Силовая установка: поршневой V-образный мотор Blackburne Tomtit мощностью 26 л.с. (19 кВт)
Летные характеристики: максимальная скорость 117 км/ч на уровне моря; крейсерская скорость 97 км/ч на оптимальной высоте; начальная скороподъемность 69 м/мин; практический потолок 4570 м; дальность полета 241 км
Масса: пустого самолета 148 кг; максимальная взлетная 256 кг
Размеры: размах крыла 9,17 м; длина 5,99 м; высота 2,21 м; площадь крыла 11,61 м2
Flight, August 1923
THE DE HAVILLAND 53 LIGHT 'PLANE
750 c.c. Douglas Engine
WHEN the rules governing the light 'plane competition for the Sutherland and Daily Mail prizes were first published we expressed doubt as to the utility of offering such large amounts for one particular performance, i.e., economy, and pointed out that under the rules, and given a calm day, there was nothing to prevent some freak machine with a very small engine and light loading from walking off with the prizes, leaving machines of much greater practical value unrewarded. The addition of the Abdulla prize for speed over a measured course has helped to a certain extent in so far as it encourages features other than "economy." Nevertheless, the risk of a freak machine winning the main prizes is by no means eliminated, and we still hold our original opinion that much more good could have been done by splitting up the very large amounts offered into a number of smaller awards, points being given for various features and performances. It is, therefore, all the more gratifying to find, on examining a number of the machines built for the competitions, that British constructors have, on the whole, taken the view that a machine with the smallest possible engine, although having a good chance of winning the economy competition on a calm day, would be of little practical value afterwards, and have, without exception, decided in favour of power and wing loadings which will give machines with a reasonably good performance and a sufficient margin of power to make them flyable even in fairly strong winds. This is distinctly encouraging, as it shows the belief among firms in the aviation industry that it is worth while designing not only and solely for the competitions, but also for the future.
A case in point is the new de Havilland light 'plane, the D.H. 53, which forms the subject of our full-page scale drawings and other illustrations this week. This machine is emphatically not a freak in any way, and frankly, if the week at Lympne provides a couple of days of flat calm, the D.H. 53 will not be over likely to collect the mileage per gallon prizes. On the other hand, should the week prove fairly windy this machine should show up extremely well, both in the "economy" and speed contests. Furthermore, if the Lympne meeting results in the development of a general interest in the low-power aeroplane and a real demand arises for a machine sturdy enough to be handled by a man of average skill in piloting, and cheap enough to buy and operate to make it a practical proposition, the D.H. 53 should certainly come as near meeting the requirements as any machine with which we are acquainted. Thus, in the following notes we are considering the machine in terms of practical utility rather than as a special design produced to win a competition bordered by narrow limits.
The de Havilland 53 is a monoplane with the wing placed low. In Germany this type is teimed a "tiefdecker," as distinct from the monoplane, having its wing resting on top of the fuselage and called a "hochdecker." It seems worth while to coin a word to describe the type in English, but until one has been selected we may refer to the type as a low-wing monoplane, reserving for the machine with the wing on top the term high-wing monoplane, and for the type in which the wing is raised above the fuselage on struts the expression which gained currency during the War, i.e., parasol monoplane. The D.H. 53 light 'plane, then, is a low-wing monoplane, with the two halves of the wing hinged to the fuselage and braced by compression struts above the wing.
This design was not chosen until after a very thorough investigation of the relative merits of the high-wing and low-wing types. The former possibly gives a slightly better aerodynamic efficiency, and it also has the advantage, from the structural point of view, that the wing struts are working in tension instead of in compression, which means that a certain amount of weight can be saved. The latter has many practical advantages, and was chosen for these by the designers of the D.H. 53. To begin with, the low-wing monoplane has its wing much closer to the ground, so that a not inconsiderable "cushioning effect" is obtained on landing. Then there is the question of stability on the ground. In the high-wing monoplane, where the distance from the wing tip to the ground is considerable, a very wide wheel track must be provided to prevent the machine from leaning over so far that a wing tip touches the ground. In this connection it should be remembered that where the wing is a considerable distance above the ground, the angle of the machine may be such that a wing tip skid would be almost useless as the tip would touch before the skid, unless the latter is very deep. In the low-wing type, on the other hand, wing tip skids of very moderate depth are elevated but a very short distance above the ground, and consequently touch as soon as the machine heels over to quite a small extent. The result is that the undercarriage itself need not be of very wide track. In fact, if it is desired to place the wheels inside the fuselage with their lower portion projecting there does not seem to be any objection to doing so with the low-wing type, as even the narrow wheel track thus afforded should be sufficient when assisted by wing tip skids coming down fairly close to the ground.
In the de Havilland light 'plane there is an exposed undercarriage, more or less, of usual D.H. Vee-type, but this has, we fancy, been chosen for reasons other than width of track, the designers holding that with the wheels partly enclosed in the body, the clearance between the latter and the ground is very small, so that taking-off may be hindered by the drag caused by long grass. Also, the ground angle of the wing is likely to be rather below the angle corresponding to maximum lift, unless the wing is set at a considerable angle to the fuselage, which means a slight increase in resistance, owing to the fact that the machine will fly tail-up when the engine is running at full power. The choice, it will be seen, is a matter of compromise, and in the D.H. 53 the usual undercarriage has been chosen, giving a ground angle of approximately 13 degrees to the wing when the tail skid is resting on the ground. The angle of incidence in relation to the fuselage is 3 degrees.
Another advantage of the low-wing type is that in designing it is possible to shift the pilot fore and aft within fairly wide limits without interfering with the wing at all. In the high-wing type it becomes necessary, usually, to cut an opening in the centre of the wing, which is generally considered to affect adversely the aerodynamic characteristics of the wing. Also the view obtained in the low-wing type is exceptionally good, except straight down. In the de Havilland light 'plane the pilot is seated sufficiently far forward to be able to see in a forward and downward direction to within a few feet ahead of the machine, so that both for landing and taking off his view should be all that can be asked. There is, perhaps, a slight objection to the low-wing type on the score that if the machine turns over on landing there is nothing to protect the pilot's head, whereas in the high-wing type the wing is between him and the ground. Experience alone will show whether or not there is justification for this contention. These light 'planes land so slowly and are so controllable that except as a result of very clumsy piloting there should be few instances of machines turning over.
Constructionally the D.H. 53 has absolutely nothing of the freak about it, and as a result of the constructional methods employed being along usual lines the factor of safety in the wing structure is everywhere at least five. This is probably more than is strictly necessary in a machine of this type, certainty more than enough for the competitions, but on the other hand for practical use under ordinary flying conditions, the extra strength is worth having, especially since it means that the machine is sufficiently robust not to be easily damaged in handling on the ground , in the shed, etc. From the potential user's point of view this a point of importance.
The fuselage is of similar construction to the larger de Havilland machines in that it is a light frame structure covered entirely with three-ply wood. There is thus no wire bracing to look after, and this form of construction has been found in practice to stand up very well to wear and tear. The four spruce longerons are connected at intervals by vertical and horizontal struts, but these simply abut on the longerons, and are not secured to them except by way of the three-ply covering. The function of the fuselage struts really is more that of preventing the three-ply covering from buckling than to tie together the four longerons. In section the fuselage is rectangular, with a fairly deep cambered deck. At certain points, where local considerations demand it, the usual spruce cross struts are supplanted by steel tubes. This, for instance, is the case at the point where the wing bracing struts meet the fuselage.
The wings are built up on two box spars having spruce flanges and three-ply walls. The flanges are spindled out internally to form a rounded channel section, thus giving a large glueing area. The spacing of the spars is normal, and very large ailerons are fitted. In front view the wing spars have a pronounced taper, with the greatest depth occurring where the wing struts meet the spars, and the smallest depth at the wing tips. At the root, where the wing is hinged to the fuselage, the depth of the section is approximately two inches, and the trailing edge is swept upward and forward to meet the lower longeron of the body. The wing section employed, if one can speak of any definite section in a tapering wing in which no two ribs are alike, is a modified R.A.F. 15, with the ordinates stepped up at the section of greatest depth. The actual R.A.F. 15 section occurs approximately where the straight leading and trailing edges meet the curves of the wing tip.
The ribs are of normal type, built of spruce, and I-section compression struts are employed. The very substantial fitting which secures the wing strut to the top of the spars is shown in one of our sketches, which also gives a good idea of the spar sections, rib construction, etc. The wing struts themselves are solid spruce of streamline section, and it will be observed that they meet at one point on the top longeron of the fuselage. Thus no wire bracing is required, the structure being triangulated.
Very simple fittings are used for attaching the wing spars to the fuselage and the struts to fuselage and spars. Altogether there are six pins (with quick-release locking wires) to undo, when the wing can be unshipped, the aileron control cables having, of course, first been cast off. The whole operation should not occupy more than a few minutes. The ailerons, it will be seen, are of large area, and the de Havilland patented differential aileron control is used. The bracket supporting the sprocket of this control is shown in a sketch. The aluminium plate on the lower surface fits flush into the wing, the only projection being the bolt to which the aileron tube from the king-post is attached. The whole makes an exceptionally clean job, and seems to be worth the extra trouble that has been taken over it. The action of the de Havilland type of differential control is, of course, to cause the upward-moving aileron to travel through a greater angle than that of the downward-moving aileron on the opposite side. Thus the yawing moment set up is smaller than where the lower flap moves through a large angle and offers a great amount of resistance. In the D.H. 53 the angles chosen for the point of attachment of the crank lever control tube is such that with a certain amount of stick movement the downward-moving flap reaches a maximum, and then, as the upward-moving flap rises further, begins to rise again. Thus, at no time during the full movement of the stick does the lower flap exceed a certain angle, pre-determined by the setting of the tube on the sprocket. During preliminary flying tests the D.H. 53 has been found to be very controllable, and it appears that lateral control is effective right up to, or even past, the stalling angle. The longitudinal controls are also very effective, while directional control is quite exceptionally good, the machine handling well even when taxying at low speed on the ground.
The 750 c.c. Douglas engine is very simply and neatly mounted on a flat horizontal engine plate, the "feet" of which rest on the longerons, as shown in a sketch. The lower portion of the crank-case, which is bolted to the upper and has semi-circular grooves for mounting in a bicycle frame, has been omitted, and the engine rests with the flat bottom of its crank-case on the engine plate. A small cowl fits over the top of the engine, and makes a very neat nose. As direct drive is used a special propeller boss has been made, which is secured to the tapering end of the crank-shaft. The diameter of the propeller varies from 4 ft. to 4 ft. 9 ins., according to whether the machine is to be used for speed work or for mileage-per-gallon competition.
A small petrol and oil tank is mounted aft of the engine bulkhead, and although it is not placed particularly high, there is sufficient head to give direct gravity feed to the carburettor, the fuel being led to the engine through a length of "Petroflex" tubing. A feature of the D.H. 53 which should particularly appeal to the owner-pilot of the future is the effective silencing of the engine. From the illustrations it will be seen that short exhaust pipes are taken from each cylinder and join a long collector pipe curving underneath the bottom of the fuselage. When the engine is running only a pleasant purr is heard, while a two-cylinder engine with open exhaust makes quite an unpleasant noise, owing to the fact that with but two cylinders there is no overlapping of the exhausts, which are consequently heard as distinct and separate cracks.
The undercarriage of the D.H. 53 is of the usual de Havilland type with the exception that no oleo gear is fitted. On the larger machines this type of chassis works extremely well, and there is no reason to doubt that it will be equally suitable for the small machine.
The tail is very similar to that of last year's D.H. gliders in general shape and construction, and rudder and elevator are operated by cables placed externally on the fuselage where they can be readily inspected.
All the main dimensions of the D.H. 53 light 'plane are shown on the accompanying general arrangement drawings. The empty weight of the machine is 310 lbs., "dry." With a 168 lb. pilot, one gallon of petrol and half a gallon of oil the total loaded weight is 490 lbs. As the wing area is 120 sq. ft. the wing loading is just over 4 lbs. per sq. ft. The maximum speed is probably in the neighbourhood of 70 m.p.h., while the landing speed appears to be about 30 m.p.h As already stated, the machine is very manoeuvrable, and should appeal to the private owner-pilot. Two are being built for the competitions, one of which will be piloted by Captain de Havilland himself
Первый полет de Havilland DH.53 "Humming Bird" выполнил в 1923 году. Его можно считать предтечей современных сверхлегких самолетов. Машину поддерживает в рабочем состоянии фонд "Shuttleworth Trust".
THE D.H.53: Three-quarter rear view. This illustration gives a good idea of the shape of wings and tail, also indicates that the view from the pilot's cockpit is exceptionally good.
The D.H. 53 (750 c.c. flat-twin Douglas).
THE D.H.53: Front view, showing dihedral, wing bracing, struts, etc.
THE D.H.53: Three-quarter front view, and, on the left, a larger view of the engine and undercarriage.
THE D.H.53 LIGHT MONOPLANE: This machine, fitted with a 696 c.c. Blackburne engine, has been sent to Prague, where it will give demonstration flights at the Kbely Aerodrome. It was on a similar machine that Mr. Alan J. Cobham flew from London to Brussels in less than four hours.
THE D.H.53 LIGHT MONOPLANE AT HENDON: A "close-up" of the inverted Blackburne engine.
MODIFIED D.H.53 - Humming Bird single-seat ultra-light, built at Stag Lane in 1924 (c/n. 103; ex-G-AUAC, old Australian registration form). Standard production motor (32-h.p. Bristol Cherub III 2-cylinder engine) has been replaced by heavier 35-40-h.p. ABC Scorpion 3-cylinder motor resulting in cut-back nose, with airscrew just clearing airframe. Prototype (1923, c/n. 101, G-EBHX) had 700-c.c. Blackburne engine giving maximum speed of 76 m.p.h. for a.u.w. 490 lb. Span 30 ft. 1 in.; length 19 ft. 8 in.
F. J. V. Holmes' D.H.53 G-EBHX at Barton in 1930. This was the “small flat-twin engined low-wing monoplane” which the author discovered in a neglected corner of the hangar. The aircraft is now with the Shuttleworth Collection.
De Havilland D.H.53 Humming Bird G-EBQP began life as J7326, one of eight ordered for evaluation as primary trainers for the RAF, and was also earmarked for experimental launch and retrieval trials operating from the rigid airship R33. at that time it had a 32 h.p. Bristol Cherub engine. Subsequently it was one of several ex-RAF D.H.53s made airworthy by P.G.N. Peters and his fellow members of the Royal aircraft establishment aero Club at Farnborough. Granted its Certificate of Airworthiness (C of A) on May 13, 1927, in January 1928 its ownership passed to Fg Off A.F. Scroggs at Henlow. It ended its life in a crash at Hamble on July 21, 1934.
THE NOTTINGHAM FLYING MEETING: Event 1 on Monday's programme - F/O. Mackenzie Richards starting at scratch in the Papplewick Stakes on the D.H. 53.
Mr. R. W. Knight, who won the Landing Competition in his D.53 ("Cherub").
В 1955 году авиетку Humming Bird, ныне принадлежащую Фонду Шаттлуорта, нашли в частном саду в сильно поврежденном состоянии и восстановили с помощью технической школы фирмы "de Havilland".
THE LIGHTER SIDE: The little D.H. 53 used for a comic turn.
This is the D.H.53 monoplane (Bristol "Cherub" engine), owned by the R.A.E. Club at Farnborough, who have reconditioned it to the extent that only the wings, engine, etc., were not built by them.
A very fine little Machine: The de Havilland 53 belonging to the Seven Aeroplane Club flies like a small Scout in spite of the fact that its engine is an A.B.C. of some 35 h.p. only.
WINNING LIGHT 'PLANES AT HENDON: Capt.H. S. Broad on the D.H.53 monoplane (Blackburne engine), winner of the Handicap Race
THE LIGHT 'PLANE RACE FOR THE GROSVENOR CHALLENGE CUP: In 7 Cobham is seen standing the de Havilland 53 on its wing tip while rounding the aerodrome turning point.
A LYMPNE REMINISCENCE: Bert Hinkler on the Avro "Avis" leading Boyes on one of the D.H.53's. The picture gives some impression of Hinkler's masterly handling of the "Avis."
DE HAVILLAND MONOPLANES: The lower photograph shows Major Hemming wheeling out No. 12 for a flight at Lympne. This machine is known as the "Hemming-Bird," while the second de Havilland is called the "Humming-Bird." The upper pictures show No. 8 in flight, piloted by Capt. de Havilland, and No. 12, piloted by Major Hemming.
REMINISCENCES OF LAST YEAR'S LYMPNE COMPETITIONS: The photograph shows Mr. Broad flying the de Havilland 53, while the inset is a view from underneath of the "Wren" on which Longton tied with James for the consumption prize.
THE RACE FOR THE GROSVENOR CHALLENGE CUP: No less than 21 machines faced the starter for this race, a record number. The result was that machines frequently got bunched together at the turning points. Our photograph show one of some such incidents. In 1 are seen the D.H. 53, the Farnborough "Cygnet," and the Cranwell biplane approaching the aerodrome turning point.
THE LIGHTER SIDE OF THE R.A.F. DISPLAY: Event No. 3, the Light Aeroplane Race, open to the Directorates of the Air Ministry, on D.H. 53's. Above, four of the six D.H. 53's entered finishing their first lap (about 5 miles). Below, the line up of the six youngsters before the start. Inset, the winning machine (Wing-Comdr. W. S. Douglas, M.C., D.F.C., "Equipment") finishing.
A LITTLE COMIC RELIEF: Mr. Cousins caused much amusement by arriving in a D.H. 53, wearing a bowler hat, which he raised as he flew past the enclosures. On the right he is seen with attache case and umbrella after alighting.
THE BOURNEMOUTH AVIATION MEETING: The line up for the first event on Sunday - the Private Club Handicap, won by Capt. de Havilland's "Moth" (the third machine on the left).
AIR-COMMODORE C. A. H. LONGCROFT TRIES THE DE HAVILLAND LIGHT 'PLANE: Our photograph shows the Commodore discussing the machine with Capt. Broad, while in the inset the machine is seen on a pretty banked turn. The machine was also flown by Wing-Commander Pretyman.
A D.H.53 IN AUSTRALIA: In the cockpit, "Capt. F. W. Follett, Superintendent of Aircraft, Civil Aviation Branch of the Department of Defence. Our photograph also shows Capt. Reid, Mr E. J. Hart, Editor of "Aircraft" (in the sweater, Mr. McArthur Onslow (in front of Follett), Capt. Jones. M.C., D.F.C., Superintendent of Flying Operations and pilot of the G-AUAB round-Australia D.H.50, is talking to Col. Brinsmead, O.B.E., M.C., Controller of Civil Aviation.
Perfectly Simple: Major Hemming and an assistant at Lympne wheeling out the de Havilland monoplane ''Sylvia II" by holding on to the propeller and letting the tail rise off the ground.
THE LIGHTER SIDE OF THE R.A.F. PAGEANT: Two light 'planes, which led in the "Fly Past": the Parnall "Pixie" and the D.H.53, both fitted with Blackburne "Tomtit" engines.
LIGHT 'PLANE COMPETITIONS: The official "shed." No. 8, one of the de Havilland machines, and No. 13, the Handasyde monoplane, in the shed ready for filling up.
Home. It was in this Barton hangar that the author served his apprenticeship. On the right is cricketer Peter Eckersley’s Avro Avian. Other aircraft include Avro 504Ks, a D.H.53 and a D.H.9.
A Sign of the Times: A batch of 12 D.H.53 light 'planes coming through the shops at Stag Lane.
THE R.A.F. IN LORD MAYOR'S PROCESSION: A workshop lorry towing a D.H.53.
The D.H.53 light monoplane "stunting" at Hendon meeting.
LIGHT 'PLANES AT LYMPNE: Some constructional details. 5. Wing strut attachment to fuselage on de Havilland monoplane.
THE D.H.53 LIGHT 'PLANE: Some constructional details. 1, General view of the undercarriage, of which some of the details are shown in 2; 3 shows the engine mounting, cowling, tank, etc.; and 4, the very simple engine plate. The fitting for one of the wing-tip cane skids is shown in 5. In 6 the construction of spars, ribs, and compression struts is indicated, as well as the substantial fitting for the wing struts. Details of the aileron sprocket mounting are shown in 7.
D.H.53 Light 'Plane 750 c.c. Douglas Engine