Flight, June 1920

THE MARTINSYDE MACHINES

The F.3. (1917)

   We now come to another member of the Martinsyde family, affectionately known at the works as "Mother." This was a righting scout, and went through its tests in November 1917. As the first single-seater in the F. class, it was natural that it should be known as mother. From the table it will be seen that this machine had an extraordinarily good performance, its speed at ground-level being 142 m.p.h., while at an altitude of 16,500 ft. the speed was still 130.5 m.p.h. The figures for climb are as follows: 6,000 ft. in 3 mins. 35 secs., 10,000 ft. in 6 mins. 45 secs., 15,000 ft. in 11 mins. 55 secs., and 20,000 ft. in 24 1/2 mins. In spite of the exceptional speed of this machine, the landing-speed is only 45 m.p.h. At the same time the machine is very easy to manoeuvre and quick on the controls. It may, perhaps, be mentioned that this machine was described in an official report as "A great advance on all existing fighting scouts." From the illustrations it will be seen that the pilot is placed high in relation to the top plane, which arrangement gives him an excellent view. The roof-shape of the coaming behind the pilot's head should be noted as one of the features of this machine.


The F.4. (1918)

   The last of the Martinsydes to be designed and built for war purposes was the F.4, or "Buzzard," as she is commonly called. She was designed and built in 1918, and tested in June of the same year. She was designed with the purpose of beating all performances of every other machine both Allied and Enemy. But for the cessation of hostilities, it is not to be doubted that the "Buzzard," as a military machine, would have made a world-wide reputation for herself. The machine, both as regards appearance and general performance, is, perhaps, the finest that has ever left Mr. Handasyde's drawing board. She is fitted with a 300 h.p. Hispano-Suiza engine, which gives her a ground-level speed of 145 m.p.h., while at 15,000 ft. the speed is 134 m.p.h. The figures for climb are as follows: 6,000 ft. in 3 mins. 40 secs., 10,000 ft. in 6 mins. 40 secs., 15,000 ft. in 11 mins. 45 secs, and 20,000 ft. in 19 mins. 40 secs. In spite of this excellent speed and climb, the F.4 lands at only 45 m.p.h. The; standard machine carries fuel for 2 1/2 hours flight at full speed, but by fitting a larger tank a much longer range could be obtained, while the absence of guns and other paraphernalia of war would provide still extra load capacity, thus making the machine eminently suitable for express air mail carrying.

Flight, July 1920

The Olympia Aero Show 1920

The machines

Martinsyde, Ltd. (STAND 43) Maybury Hill, Woking.

   The Martinsyde "Semi-Quaver" is a small single-seater racing aeroplane designed to compete in the sporting events of the current year. During the first trials in March, 1920, the speed of 161.434 m.p.h. was obtained for a distance of 1 kilometre, and this performance was passed as a British record by the Royal Aero Club.
   Full details of this little machine are not, at the moment, available, but a fair idea of the general lay-out of the 'bus may be obtained from the accompanying illustrations. As will be seen, it is of the short-span single-pair strut type. The top plane, which is of larger span and chord than the lower one, is mounted on a narrow, streamlined "fairing," or keel, on the top of the fuselage, so that it is brought close to the latter almost level with the pilot's eyes. It is fitted with a 300 h.p. Hispano-Suiza, as in the other types.


The Martinsyde Machines

   Perhaps from a popular point of view the most interesting of the Martinsyde machines shown is the little "Semiquaver" racing machine, which will be piloted by Raynham in the forthcoming Aerial Derby. This machine is of diminutive size and, like all the Martinsyde machines, of the most beautiful outline imaginable. The wing span is only 20 ft. and with a 300 h.p. engine, the speed is over 160 m.p.h. As the machine is very heavily loaded (over 13 lbs. per sq. ft.) the landing speed is necessarily somewhat high, round about 70 m.p.h. (In the table published last week, the figures of loading per h.p. and per sq. ft. were transposed, and the area should be 147 sq. ft.) That the machine will give a good account of itself in the Derby is clearly not to be doubted. Generally speaking, the construction is similar to that of the other two machines, but the mounting of the top plane is unusual. Instead of the usual centre section, the top plane, which is in one piece, is attached direct to the body, which at this point has a small fin or hump swept upwards to meet the plane. The result of the absence of centre section struts and bracing is to give the machine a very neat and clean appearance.

Flight, October 1921

THE "ALULA" WING DEMONSTRATED

   OR the purpose of witnessing a practical demonstration of the application of the "Alula" wing to the needs of the fighting air service, at the invitation of the Commercial Aeroplane Wing Syndicate, of 30. Norfolk Street, Strand, London, W.C., we paid a visit to Northolt aerodrome on Wednesday of last week. Having previously referred to the "Alula" wing in FLIGHT (July 22 and August 5, 1920), we do not propose at the present moment to dwell upon the particular characteristics of this wing - especially as we hope to give a full technical report on the latest "Alula" developments very shortly - but will confine our remarks to the demonstration referred to above, and to a few points in connection with the aims of the Commercial Aeroplane Wing Syndicate.
   It may be desirable, however, briefly to outline the general principle of the "Alula" wing, and the advantages claimed for it., fey the employment of a peculiar wing-form and wing-section, very bird-like in appearance - and somewhat reminiscent of the Weiss glider - it is claimed that the air flow across the wing is maintained in a uniform direction, parallel to the line of flight, from root to tips, thus preventing end losses obtaining in ordinary "rectangular" wings, caused by the outward flow, or spilling, of the air at the tips. Or, as Mr. A. Holle, the designer of the wing, put it, the "Alula" has a "two dimensional" air flow. The "Alula" was, therefore, considered particularly suitable as an economic commercial weight-carrier, but it was suggested by Air-Vice-Marshal Sir Edward Ellington that the speed and climb claimed for the new wing would be of value in air fighting, and so a wing was designed and built for the "Aircraft destroyer" demonstrated last week.
   This wing, which has a span of 28 ft. 6 ins. and 106 1/4 sq. ft. of area, is built up entirely of wood - covering included - in the form of a cantilever. It has no spars as in the orthodox wing, but, as Mr. Holle describes it, is in itself a complete spar.
   It is mounted on a cabane above the Martinsyde "Semi-quaver" fuselage - the same machine that won last year's Aerial Derby. There is no external bracing. The original landing gear has been replaced by one having a much wider track, rendered necessary owing to the higher centre gravity of the machine.
   For the demonstration the "Semi-Alula-quaver" was piloted by our old Hendonian friend, R. W. Kenworthy, and as a comparison of performance a Service Bristol Fighter (275 h.p; Rolls-Royce) took the air simultaneously.
   This "comparison" was certainly spectacular, but hardly one for serious consideration, inasmuch as last year's Aerial Derby winner could easily hold its own against a Bristol Fighter, and we take it that the fitting of the new wing to the "Semi-quaver" was to result in even better performance. However, whilst the Bristol Fighter took off as a well-behaved Bristol should, the "Semi-Alula-quaver," although indulging in a somewhat longer run, climbed at what seemed to be an angle of about 60 degrees, and was soon well above the Bristol. In a little over one minute an altitude of 3,000 ft. was reached. Kenworthy then put up various manoeuvres around the Bristol, and on two occasions they dived down to a low altitude and flew abreast past the gathering of spectators, the "Semi-Alula-quaver," of course, shooting well ahead. Kenworthy told us later that his airspeed indicator was showing 180 m.p.h. On the whole the machine put up a very good show, seemed to handle very nicely - and it certainly is one of the prettiest machines in air we have seen.
   The demonstration was witnessed by quite a number of "big people" connected with aeronautical matters, amongst whom may be mentioned Captain the Right Hon. F. Guest, Secretary for Air, Air Vice-Marshal Sir J. M. Salmond, Air Vice-Marshal Sir Edward Ellington, Group-Capt. A. F. L. Scott, Air-Commodore Pritchard and Col. Beatty.
   Mr. Holle informed us, after the demonstration, that the purpose of the Commercial Aeroplane Wing Syndicate was to develop the "Alula" wing to meet the requirements of all types of aircraft, as he was convinced that there was unlimited scope for the application of the "Alula" principle for all purposes. The Syndicate, however, he pointed out, were not constructors, but undertook to design wings for all types of aeroplanes according to the nature of work they have to undertake.