The British Fighter since 1912

P.Lewis - The British Fighter since 1912 /Putnam/

Among the single-seat fighters designed during 1915, as weapons to deal with the marauding Zeppelins, was the A.D. Scout, known also as the Sparrow, Harris Booth of the Air Department of the Admiralty being the man responsible for the design. The machine was intended to bear aloft the Davis recoilless gun and this was to be housed in the lower part of the pusher biplane’s nacelle.
   A comparatively large gap separated the two pairs of wings, and the nacelle was attached to the underside of the upper pairs of planes. Parallel struts were incorporated in the undercarriage, their length resulting in the cockpit being at an inordinate height above ground level. Extremely large tailplane and elevator surfaces, short-coupled, were carried by the four tail-booms, in between which revolved the pusher propeller and its 80 h.p. Gnome engine. The very narrow track of the wheels combined with the high centre of gravity of the machine, could have resulted only in gross unwieldiness and instability while taxiing and during take-off and landing. Strut-connected ailerons were incorporated on all four of the single-bay wings and twin fins and rudders filled the gap at the rear of the tail booms.
   The whole concept was an unfortunate and unsatisfactory one, about the only point in its favour being the fine view enjoyed by the otherwise hapless pilot. Test flights, soon proved the fallacy of the design, to which two airframes were constructed by Blackburn. An order for a further pair of A.D. Scouts was placed with Hewlett and Blondeau but confirmation of their actual building is lacking.
The pair of A.D. Sparrow Scouts, 1536 and 1537, built by Blackburn seen under construction at Olympia Works, Leeds.
A rather curious event took place during 1917 at Mudros in the Aegean which, although it contributed nothing to fighter development, deserves to be recorded as an example of initiative and ingenuity. During his service on the station with No. 2 Wing, R.N.A.S., Flt.Lt. J. W. Alcock, well known in flying circles before the 1914-18 War and to become famous after the Armistice for his trans-Atlantic flight with Lt. A. W. Brown, designed a single-seat fighter biplane which was put together from Sopwith Triplane and Pup parts. Two engines were tried in the Alcock A.I Scout, or Sopwith Mouse as Alcock called it; the first was a 100 h.p. Monosoupape Gnome, followed by a 110 h.p. Clerget. Unluckily, Alcock was taken prisoner before his brainchild was ready but the machine was test-flown at Mudros and Stavros after completion by his colleagues. The A.I’s armament consisted of a pair of Vickers guns.
Yet another tractor scout had appeared within a month of the outbreak of war. This was the F.K.1, built by Sir W. G. Armstrong Whitworth and Co., and designed for them by a Dutch designer, Frederick Koolhoven, whose name was to be perpetuated by a prolific series of aircraft to appear under his signature for many years ahead. Before drafting the F.K.1, his first design for Armstrong Whitworth, Koolhoven had accumulated considerable experience through the successful Deperdussin monoplanes.
   In the new scout the monoplane formula was disregarded, despite its inherent quality of speed, and the F.K.1 made its debut in September, 1914. A relatively simple biplane in every way, it showed evidence of French practice in the horizontal knife-edge termination of the rear fuselage and in the omission of a fixed tailplane. The upper wings were taken over the fuselage at a considerable gap on inverted-V centre-section struts and this feature, combined with undercarriage legs spread wide apart fore and aft, gave the whole machine a rather gawky appearance. The 80 h.p. Gnome, around which the F.K.1 had been designed, was not obtainable so it flew instead with a 50 h.p. Gnome.
   The machine was modified after early tests and was given a normal fixed tailplane and larger, inversely-tapered ailerons. The F.K.1’s top speed of 75 m.p.h. on its low power reduced any chances that it might have had of competing with its counterparts from Bristol, Martin-Handasyde and Sopwith for orders and the design was abandoned.
The F.K.11 was not proceeded with but another design from Armstrong Whitworth, the three-seat F.K.5, also exhibited some equally remarkable features. It was built as the result of a War Office requirement for a multi-seat, long-range escort and anti-Zeppelin fighter, a specification to which Vickers and Sopwith also constructed prototypes.
   Armstrong Whitworth proceeded to build the F.K.5 as a large triplane with its central planes of much greater span than those above and below. The 250 h.p. Rolls-Royce engine turned its propeller immediately in front of the leading edge and between the pair of gunners’ nacelles fitted to the centre wings. A revised version as the F.K.6 was built with a different fuselage, undercarriage and nacelles but, as with so many extremely unconventional designs, the machine was not a success.
In the unending quest for fighter supremacy designers in Britain explored most layouts and, in 1916, the Armstrong Whitworth designer F. Koolhoven was responsible for a two-seat fighter reconnaissance quadruplane which, despite the complexity of its four wings, struts and pair of cockpits was, none the less, a clean and pleasing machine, especially in its final form. The prototype used the 110 h.p. Clerget engine while the modified later version, of which a few were built, had the 130 h.p. Clerget. Tests showed that the F.K.10 was not a particularly successful machine and it remained simply one of the more unusual designs of the 1914-18 War.
   Following the F.K.10 quadruplane design Armstrong Whitworth investigated an extraordinary development by Koolhoven to be known as the F.K.11 which was intended to be borne on a set of wings reminiscent of those tested by Horatio Phillips a decade before. The F.K.11’s small-chord mainplanes would have numbered fifteen, set with pronounced stagger on the same style of fuselage as that used on the F.K.10.
   The F.K.11 was not proceeded.
N511, an Armstrong Whitworth F.K.10 constructed by the Phoenix Dynamo Manufacturing Co.
The 230 h.p. Bentley B.R.2 rotary was also selected by F. Murphy as the engine for the F.M.4 single-seat biplane fighter which he evolved for Armstrong Whitworth when, in 1917, he succeeded F. Koolhoven as designer. Named Armadillo, the machine was far from elegant in appearance and embodied a boxlike fuselage which filled the relatively narrow gap between the two-bay wings. The two Vickers guns were housed in a peculiar fairing which curved from the front face of the engine cowling to the top of the upper wings. Being tested in September, 1918, the Armadillo prototype X19 was a late-comer among the War’s fighters and, with its comparatively poor view from the cockpit, stood little chance of a production order.
Two further single-seat fighters were planned under the R.A.F. Type 1 conditions. These were the Armstrong Whitworth Ara and the Nieuport Nighthawk but neither machine was ready before the beginning of 1919.
   Designed by F. Murphy, the Ara shared the same unhappy type of engine as the Nighthawk - the 320 h.p. A.B.C. Dragonfly 1 - and retained the same two-bay wing layout as Murphy’s earlier Armadillo. The fuselage was unusually deep-sided towards the rear where it would normally have been expected to have tapered steadily in elevation. In F4971, the first prototype, the fuselage rested on the lower wings but F4972 introduced greater gap between the mainplanes, resulting in the lower wings passing beneath the fuselage. The fore-part of the fuselage housed two Vickers guns and the Ara turned in the useful top speed at ground level of 150 m.p.h. The Ara was typical of the trend of the final generation of fighters which made their debut at the end of the War and this styling was shared by the Nieuport Company’s Nighthawk.
During this time, one of the most important of the new British singleseat fighters of the early post-War era was being developed at its prototype stage. Prior to Maj. F. M. Green’s departure in 1917 from the Royal Aircraft Factory to design for the aviation section of the Siddeley-Deasy Motor Car Co. at Coventry, he prepared the preliminary layout for another fighter in the Factory’s Scouting Experimental series, based on the installation of a two-row fourteen-cylinder radial engine - the 300 h.p. R.A.F.8. Once Maj. Green, J. Lloyd and S. D. Heron had settled down to work at the Siddeley-Deasy offices, the design was developed in earnest to emerge as a sprightly-looking biplane, the Siddeley S.R.2 Siskin, in mid-1919. At the same time, at Maj. Green’s instigation the Company had gone ahead with the development of the R.A.F.8 engine and completed it as the Jaguar.
   The Siskin flew first in July, 1919, with the unfortunate choice of the 320 h.p. A.B.C. Dragonfly 1 as its power plant, but this was eventually replaced by the Jaguar which had been turned into a reliable and successful unit by the Summer of 1922. The prototype Siskin followed the usual all-wood construction and fabric covering of the war period and carried the standard pair of Vickers guns on its nose-decking as armament. The Siskin was not ordered at the time but much was to be heard of it later in its revised and developed version.
J6492, the third Bristol Badger.
Often alternative combinations of armament were experimented with on the squadrons but only comparatively rarely did a pilot fighting at the Front have a direct say in the design of a fighter aircraft itself. One such case was in the Austin-Ball A.F.B.1 single-seat biplane which was finished in July, 1917. Until the time of his death in action on 7th May, 1917, Ball had kept in direct touch with the evolution of the A.F.B.1. Although an ugly machine, its saving grace was a maximum speed of 138 m.p.h. at ground level on the 200 h.p. of its Hispano-Suiza engine and a good performance in rate of climb and ceiling. The installation of the A.F.B.1’s pair of Lewis guns was of note; that in the fuselage fired through the centre of the propeller shaft, while the other occupied a Foster mounting on the upper centre-section. Despite its abilities the machine was not selected finally for production.
During 1917 the Austin Motor Co. decided to design a single-seat fighter to Specification A.1A but, rather surprisingly in view of the generally-conceded superiority by then of the well-developed biplane, their tender appeared at the beginning of 1918 as a triplane - the A.F.T.3 Osprey. The machine was fairly small and, as was to be expected with the power of the 230 h.p. Bentley B.R.2, the overall performance was quite creditable. The standard armament scheduled for the Osprey was a pair of fuselage-mounted Vickers but X15, the sole prototype, carried temporarily a Lewis gun in addition. However, against the new biplanes then appearing the Osprey stood relatively little chance of adoption and went the way of so many hopefully-created prototypes.
The sole example of the A.F.T.3 Osprey to be completed and flown.
The A.F.T.3 Osprey was intended to compete with the Snipe, but proved inferior.
The same fate befell another aeroplane built by Austin before the War’s end. This was a proposed replacement for the Bristol F.2B, named the Greyhound, and was a two-seat, two-bay biplane armed with two Vickers guns for the pilot and a single Lewis for the gunner. The machine was a promising design, constituting a serious effort to embody in every way recommendations resulting from active operation of previous types. To enable the Greyhound to fulfil its purpose of fighter reconnaissance to the best advantage, very comprehensive equipment was installed. One less happy aspect of the design was in the choice of engine, the 320 h.p. A.B.C. Dragonfly 1, a unit which was to prove unreliable and the undoing, regrettably, of a number of prototypes designed around it in the hope of making good use of its expected high output of power.
Tempted also by the idea of the small scout, A. V. Roe showed their conception in the Type 511 Arrowscout, in reality a scaled-down 504 with single-bay sweptback wings and an 80 h.p. Gnome. The machine was tested by F. P. Raynham and turned in a top speed of 100 m.p.h. but made no further progress. One of its advanced features was the incorporation of airbrakes in the lower wing roots, an early example of their use.
Avro 511 Arrowscout
The unqualified success of the Avro 504 prompted the parent company to construct during early 1916 a two-seat fighter variant under the type number 521. The wing structure was cleaned up by conversion to single-bay cellules and the same streamlining process applied to the undercarriage resulted in a simple V-strut structure. The rear cockpit was set some distance behind that of the pilot, above whom was a generous cut-out in the trailing edge of the centre-section.
   The 110 h.p. Clerget powered the Avro 521, which was test-flown by F. P. Raynham and found to have disagreeable flying characteristics. Nevertheless, despite the crash of the prototype in the hands of an R.F.C. pilot, twenty-five production 521s were built but did not apparently reach operational service in their intended role.
Another auspicious two-seat design which was unable to make the grade once the Bristol machine had gained a firm foothold was Avro’s 530, completed in July, 1917. Careful attention had been paid to producing an airframe for the two-bay biplane which was designed to use the 300 h.p. Hispano-Suiza engine. The current shortage of this engine dictated the installation of the 200 h.p. version of the same make and the 530 was tested also with the 200 h.p. Sunbeam. Unusual features of the design were the deep fuselage filling the entire wing gap, the fairings applied to fill the openings between the undercarriage V struts, and the flaps which formed the trailing edges of the wings. Two guns were carried - a Vickers for the pilot and a Scarff-mounted Lewis in the rear cockpit.
A. V. Roe followed up their 530 two-seat fighter with another fighter design - the single-seat 531 Spider. The new prototype was completed by April, 1918, and turned out to be a 110 h.p. le Rhone-engined biplane of striking appearance. In the interest of quick production particular attention was paid to using readily-available 504K parts in the airframe but, despite this admirable object, the Spider was a distinctive machine. The main feature which caught the eye immediately was the system of three pairs of V struts on each side which braced the unequal-span wings without the assistance of bracing wires, the upper wings being set close to the top of the fuselage so that the pilot’s head projected through the open centre-section. A peculiar point about the Spider’s armament was the fitting of only one Vickers gun at a time when two machine-guns had become more or less standard. Tests proved the machine to be excellent for its purpose with admirable manoeuvrability, its top speed at ground level with the 130 h.p. Clerget fitted being 120 m.p.h.
   Another version of the Spider was planned as the 531A, based on the 130 h.p. Clerget with different biplane wing cellules and orthodox struts and wire bracing.
Avro 531 Spider.
While the Camel, S.E.5 and other production types continued to bear the brunt of the fighting in the air, prototypes of new fighters continued to appear in Britain. Among the companies which made bids to establish themselves as fighter constructors was the paradoxically-named British Aerial Transport Co., the chief designer of which was F. Koolhoven, late of Armstrong Whitworth. Koolhoven’s initial design for his new firm was the F.K.22 Bat, a single-seat fighter biplane drawn up around the 120 h.p. A.B.C. Mosquito radial engine, the airframe consisting of two-bay, equal-span wings fitted to a shapely monocoque fuselage. A particularly unusual feature of the F.K.22 was the location of the cockpit immediately underneath the upper wings so that the pilot’s head projected above the centre-section. Failure of the proposed engine brought about redesign to make use of a later A.B.C. radial unit, the 170 h.p. Wasp, with which the Bat was renamed Bantam. Cancellation of development of the Wasp resulted in flights being made early in 1918 with rotaries - the 100 h.p. Monosoupape Gnome and the 110 h.p. le Rhone.
   To distinguish it the Gnome version was referred to as the Bantam Mk.II, while the F.K.23, a smaller version, became the Bantam Mk.I. The Mk.I was bedevilled by dangerous spinning characteristics but the design’s speed and manoeuvrability resulted in an initial batch being ordered, with several alterations which went most of the way to eliminating the early faults. After nine Bantams had been constructed production was stopped when the A.B.C. Wasp was withdrawn as a production unit owing to persistent trouble with it. Armament of the Bantam was scheduled to be a pair of fuselage-mounted Vickers guns.
Production B.A.T. Bantam Mk.I.
Frederick Koolhoven designed a further fighter for the B.A.T. Company to meet the R.A.F. Type 1 Specification, the F.K.25 Basilisk completed during 1918. The machine was another of those developed to use the power of the 320 h.p. A.B.C. Dragonfly radial engine and was on the general lines of the earlier Bantam but with the pilot given more conventional accommodation in a cockpit set further aft in the monocoque fuselage. Two-bay wings were again used and the undercarriage followed Koolhoven’s favourite style of separate units with a broad track. The Basilisk’s armament consisted of a pair of fuselage-mounted Vickers guns. The second prototype embodied minor modifications but the Basilisk failed to make any headway towards production.
F2907 B.A.T. Basilisk fitted with plain ailerons.
Among the various types of aircraft produced by William Beardmore and Co. was a version of the Sopwith Pup redesigned for Beardmore by G. Tilghman Richards specifically for shipboard use. Saving of space has, from the beginning, always been a primary consideration for naval aircraft and, in the W.B.III, the wings were made to fold by eliminating the stagger and fitting a revised system of struts. To reduce height the main landing-gear folded up into the belly of the fuselage, the length of which had been increased. The S.B.3D designation was applied to the version with jettisonable undercarriage; S.B.3F denoted folding landing-gear. Production W.B.IIIs served with the Fleet and were armed with one Lewis gun on the upper centre-section.
Two other single-seat fighter designs, intended for the R.N.A.S., appeared from Beardmore in the course of 1917. The W.B.IV was a two-bay biplane designed around the 200 h.p. Hispano-Suiza, the engine being installed in the fuselage above the lower wings and driving its propeller by an extension shaft, which was straddled by the pilot in his high-set cockpit in the nose ahead of the leading edge of the wings. N38, the sole W.B.IV built, was notable also in having a streamlined flotation tank faired into the fore-fuselage and at first had floats under each wingtip. The machine carried two guns - a forwards-firing Vickers installed to port in the nose and a Lewis fitted at an upward angle in front of the pilot.
The Beardmore W.B.V single-seat fighter biplane also used the 200 h.p. Hispano-Suiza but was built specifically to make use of the 37 mm. Puteaux shell-gun which fired its rounds through the centre of the propeller shaft. In other respects the machine was of normal two-bay tractor layout but misapprehension concerning the safety of the pilot with the Puteaux in action led to the heavy gun’s replacement by one forwards-firing Vickers and upwards-firing Lewis gun. Interest in the W.B.V finally petered out and development stopped.
Contemporary with the A.D. Scout was the Blackburn Triplane, N502, which was designed late in 1915 and which exhibited several features in common with the A.D. machine. In particular, the Triplane possessed the same exaggerated gap between the tail booms which carried also the similar style of broad-span horizontal tail surfaces. The nacelle was mounted ahead of the centre wings of the single-bay cellules, and an undercarriage of normal height and track was provided. Additional ground stability was ensured by tip skids under the interplane struts.
   The single forwards-firing gun was installed in the lower half of the nose of the nacelle, at the rear of which was fitted the 100 h.p. Monosoupape Gnome; the 110 h.p. Clerget was an alternative engine tested in the Triplane. Compared with the size of the fins, the rudders were large, and a fair measure of lateral control area was provided by fitting strut-connected ailerons on each of the six wingtips.
Blackburn Triplane fitted with 100 h.p. Monosoupape Gnome.
In the North, the Blackburn Company started in 1917 to construct their N.1B single-seat, flying-boat fighter - also a pusher using the 200 h.p. Hispano-Suiza and of refined aerodynamic form. Progress was slow so that, when the end of the War came, only the hull was ready. Intended armament was a single Lewis gun in front of the pilot.
Yet another unsuccessful contender against the Snipe was the Boulton and Paul P.3 Bobolink, a single-seat biplane fighter which was completed in 1918. Designed by J. D. North, responsible for the design of several well-known pre-War Grahame-White machines, the Bobolink - originally named the Hawk by Boulton and Paul - was a competent product, based on the 230 h.p. Bentley B.R.2 engine and fitted with staggered two-bay wings employing the increasingly popular N-type interplane struts. The Bobolink was armed with the usual pair of fuselage-mounted Vickers guns and reached a top speed at 10,000 ft. of 125 m.p.h.
C8655, the Boulton and Paul P.3 Bobolink erected at Mousehold, in its original form, without ailerons on the lower wings (236 h.p. B.R.2 engine).
Meanwhile, also at Bristol, another single-seat scout had taken shape. During the previous year, Frank Barnwell, one of Coanda’s prominent fellow designers, started on a new design under works number 206 using parts of Coanda’s defunct monoplane S.B.5. Harry Busteed contributed to the design which evolved as a trim single-bay biplane with staggered wings and powered by a semi-cowled 80 h.p. Gnome. After its initial flight by Busteed at Larkhill on 23rd February, 1914, the Scout A was put on display at that year’s Olympia Aero Show. Immediately afterwards larger wings of 24 ft. 7 in. span were substituted for the original ones of 22 ft. During its A.I.D. tests with Busteed, on 14th May, the machine showed a top speed of 97 m.p.h. and a climb rate of 800 ft./min. but the prototype was lost in the English Channel on 11th July, 1914, while Lord Carbery was competing in the London-Paris-London race.
   The Scout A had shown such promise that two modified versions were produced as Scouts B for the R.F.C. and were numbered 633 and 634. The Bristol Scouts A and B had been constructed on completely conventional lines with wire-braced box-girder fuselage, wooden structure throughout and fabric covering.
   While the Sopwith company were developing the Tabloid for war, at Bristol a pair of new prototype scouts were being completed under Frank Barnwell’s direction, designated Scout B. Both were improved versions of the original Scout A which had been lost in the English Channel on 11th July, 1914. The new machines used the 80 h.p. Gnome engine and had double flying wires installed. Other differences included an undercarriage of broader track, a rudder of increased area, large skids added under the wings, and a full engine cowling with external ribs around its periphery, which had a similar appearance to the cowling fitted to Lord Carbery’s le Rhone engine in the Scout A.
   The two Scouts B were sent to Farnborough on 21st and 23rd August respectively for their official tests, following which both were posted to France for use with the R.F.C. during the first week of September. On arrival one was added to the strength of No. 3 Squadron, where it was armed with a rifle mounted on each side of the fuselage at an angle of 45° to fire forward outside the propeller disc; the other Scout B went to No. 5 Squadron. Two months after the pair of Bristols made their appearance on the Western Front, a further twelve were ordered for the R.F.C. on 5th November, 1914.
   Just over a month later, on 7th December, the Admiralty followed with an order for twenty-four to equip R.N.A.S. units. These production machines received the designation Scout C but were basically indistinguishable from the Scout B, apart from the new version’s revised engine cowling with its smooth outer surface and rather small frontal opening. The machines ordered for the R.F.C. were delivered in the following March, to be added singly or in pairs to reconnaissance units where their duty was to protect the two-seaters as they went about their dangerous observation duties over the opposing armies enmeshed in the struggle along the front line. The Bristol Scout C came on the scene before the idea had taken root of forming complete squadrons of scouts alone and so, for this reason, the type found itself spread in this way over the reconnaissance squadrons. Such a successful and reliable flying machine could well have been employed as the equipment of fighter squadrons if the concept of such formations had been realized earlier and had the machine been able, so early in the conflict, to take advantage of an interrupter or synchronous gun-firing gear.
Bristol Type 5 Scout D.
Although his S.B.5 had become a victim of the ban, Coanda still retained his enthusiasm for a military design and transferred his ideas to a two-seat gun-carrying pusher biplane layout which was constructed during 1913 as the Bristol P.B.8, works number 199. A compact machine of 27 ft. 6 in. span and length, it was powered by an 80 h.p. Gnome with the propeller revolving between the closely-set pairs of tail booms. The usual Coanda-style four-wheel landing-gear supported the P.B.8 but, although it was completed at Brooklands, it was not flown and had never been a popular project with the drawing office from the start. Coanda indulged in several other unusual designs for all-steel pushers in the midst of the general enthusiasm aroused for fitting a gun to an aeroplane but none of them progressed to the construction stage. In his search for a satisfactory layout to incorporate a gun, Coanda was forced to adhere to the pusher type of machine by the lack of any gear to ensure safe firing through a tractor propeller’s path.
Bristol P.B.8
In the West Country, at Bristol, Henri Coanda turned his hand to a design for the Breguet firm for a small biplane single-seat scout, the S.S.A. No. 219 which Harry Busteed flew and crashed at Filton early in 1914. The entire front portion of the machine’s fuselage was armoured by constructing it as a riveted sheet steel monocoque, automatically bringing forth the nickname of the Bath. A large spinner with an annular cooling slot faired the propeller into the engine cowling and skids extending to the rear of the wheels took the place of the usual single tailskid. Another advanced feature was the castoring of the wheels as an aid to crosswind landings. When the almost complete lack of ground clearance for the large propeller, then rather an obsession with Coanda, was pointed out to him by the drawing office staff, back came his usual answer “I don’t care, I make so!”.
Although neither the T.T.A. nor the S.2.A passed into production, Frank Barnwell’s next two-seat fighter design for the British and Colonial Aeroplane Company was destined to be an outstanding success and to have many years of excellent service ahead of it.
   By the beginning of 1916, it had become quite obvious that a replacement was imperative for the primitive and obsolete two-seaters plodding their way warily across the increasingly dangerous skies over the Front. By March of that year, Barnwell was able to settle down to transferring to paper his idea of an advanced and powerful new two-seater. With a considerably enhanced fund of experience to draw upon, his versatile mind devised a layout for a biplane of eminently purposeful aspect.
   At first the new project was known as the R.2A with the intended engine to be the 120 h.p. Beardmore. To obtain the desired performance it became obvious that more than 120 h.p. would be needed and thought was given to using the more powerful Hispano-Suiza as an alternative. Barnwell’s mind was finally made up for him by the advent at a most propitious time in April, 1916, of a newcomer to the range of Rolls-Royce aero engines - the twelve-cylinder water-cooled V Falcon of 205 h.p. Never satisfied that significantly increased output could not be gained by intensive development, Henry Royce was able steadily to improve the rating to 228 h.p. in May, 247 h.p. in February, 1917, and 262 h.p. by April, 1917.
   The Falcon was a gift to Barnwell of a fine, reliable, powerful engine around which he proceeded to completely redesign the R.2A as the Bristol F.2A Fighter. The power unit was well blended into a fuselage of rectangular section which tapered in side elevation to a knife-edge at the tail, and which was suspended by struts between the two-bay, equal-span wings. In deference to the essential requirement in a two-seat fighter that the pilot and gunner should be able to communicate immediately with each other, the cockpits were adjacent and in every other way the needs of the crew for their utmost efficiency were borne in mind in the layout. The pilot’s view was enhanced by adequate stagger of the wings and by cut-outs in the centre-section trailing edge and roots, while the gunner was given as broad a field of fire as could be arranged.
   Two prototypes were soon ordered but incorporating different engines - one with the Falcon Mk.l and the other with the 150 h.p. Hispano-Suiza. Work on the airframes was started during July, 1916, and 9th September saw the Falcon-powered A3303, the first machine, ready. Modification to the engine’s radiators soon took place when the pair originally fitted, one on each side of the fore-fuselage, were removed to improve the view for the pilot and replaced by a neat installation around the nose ahead of the engine. A3304, the Hispano-Suiza-powered F.2A, was complete some six weeks later on 25th October. The F.2A’s pilot was provided with a single Vickers gun installed in the centre of the nose and covered by the cowling so that it fired through an orifice in the radiator face. The observer’s Lewis was carried on a Scarff ring.
   The F.2A was an instant success and went through its trials with flying colours to achieve performance figures which exceeded those expected. An initial order for fifty was placed, to be powered with the Falcon to circumvent the shortage of Hispano-Suizas, and with revised wingtips.
   The first operational squadron to use the F.2A was No. 48, which went into action with the machine on 5th April, 1917, but suffered unexpectedly high losses immediately owing to the lack of appreciation by the crews of the vastly superior capabilities of their mounts compared with previous two-seaters. Once the speed and great manoeuvrability inherent in the Fighter were recognized, the machine came into its own in combat with the pilot able to use his gun really effectively and the observer simultaneously making the most of his armament. The technique which had to be learned and exploited was one of flying and fighting with the machine in a manner hitherto reserved for a single-seater.
   Even after the deletion of the side radiators, the forward view from the pilot’s cockpit was still not all that it could be and was improved by incorporating downward slope in the upper longerons from the rear cockpit forward to the bearers for the engine. The modified machine went into production as the F.2B and proceeded to enhance the reputation already earned by the F.2A.
   The Biff, as it soon became affectionately known, proved itself to be a brilliant design and an outstanding success among the British warplanes of 1914-18.
   Although the Sopwith 1 1/2-Strutter had pioneered the two-seat armed tractor layout successfully, Frank Barnwell’s Bristol Fighter marks the start of the classic concept and employment in battle of the single-engine, two-seat, high-performance fighter, born in the heat of war and continued into the years of peace as a type of aircraft in the development of which British designers excelled. Provided that sufficient power were available from the engine, around which the machine was designed, the two-seat fighter could prove itself to be a very welcome and useful addition to air strength. The twin-engine multi-seat concept for a fighter was a far less happy combination owing to the attendant drastic sacrifice of manoeuvrability, which its size and layout involved, and which was not a pronounced feature of the single-engine formula. Some loss of performance was inevitable in the two-seat fighter, owing to increased size and the extra weight of airframe and gunner, but the Bristol Fighter was able to offset these disadvantages handsomely by virtue of its excellent, powerful Rolls-Royce engine.
The Bristol F.2B, among the most successful of the 1914-18 two-seat fighters.
Bristol Fighter Mk.III
In contrast with the situation prevailing in Britain, the monoplane had thrived on the Continent as a military machine in both France and Germany. The type had consequently received its full share of attention to development and both countries possessed a fairly useful range of monoplanes in service. By comparison, progressive experience in the design and construction of monoplanes in Great Britain had suffered severely as a direct result of the ban of 1912 and the consequent concentration, to its virtual exclusion, on biplanes, triplanes and even quadruplanes.
   The advent of the Bristol M.1A single-seat monoplane fighter in September, 1916, was therefore an event of some considerable significance as Frank Barnwell had been given sanction by the British and Colonial Aeroplane Company to design it during July, 1916, despite continued official disapproval of the form for Service equipment. Such short-sighted behaviour in official circles, exhibited in various forms on many occasions, militates directly against accumulation of invaluable experience in design, construction and operation which those striving in all good faith on behalf of their country are entitled to acquire for its protection and continued well-being. Anything less than whole-hearted encouragement and assistance to those whose direct responsibility is the strength of the armed forces for the shielding of the population, is playing straight into the hands of the country’s enemies and is a scandalous denial to its brave sons of the quality of equipment which they have every right to expect to be provided for them.
   The monoplane ban of 1912 meant the loss of several years of steady development which Great Britain could ill afford, particularly since her traditional protection of the water surrounding her had been shown three years earlier as being no longer her complete safeguard. She could now be attacked by air from the Continent and consequently needed to exploit every conceivable means for her protection. The banning of a particular class of fast aeroplane was certainly no way of furthering this object and even the Bristol Monoplane in Barnwell’s advanced style was unable to make much headway against the opposition, a resistance which was to face the monoplane until the mid-1930s.
   The 110 h.p. Clerget powered the M.1A and the designer aimed at achieving as streamlined an installation as possible by employing a spinner with a large diameter, leaving a cooling slot between itself and the cowling. A simple rectangular-section wooden basic fuselage was faired to circular form with the usual arrangement of formers and stringers. The wings were mounted in the shoulder position and braced by wires from a central cabane over the cockpit.
   Construction of the prototype A5138 was so quick that it was ready in September, 1916, for testing by Freddy Raynham. The machine’s top speed was a rewarding 132 m.p.h. and a further four examples were constructed as M.1Bs with slight modifications and armed with a single synchronized Vickers gun on the port decking.
   News of the new fast and handy monoplane fighter, which soon circulated among squadron pilots, raised high hopes and anticipation of its appearance in France. Such was not to be, however, and the landing speed of 49 m.p.h. was stated to be too high in justification of the rejection for use on the Western Front. One hundred and twenty-five were, nevertheless, ordered into production as the M.1C using the 110 h.p. le Rhone and having the gun mounted centrally and synchronized by the Constantinesco gear. The M.1C did manage to see operational service in the Middle East but its denial to the pilots of the Western Front stands out as one of the worst examples of official incompetence and ineptitude extant. The issue in quantity of the M.1C to the R.F.C. in France could have wrought a great change in the Allies’ favour in the fighting in the skies.
While the T.T.A. was undergoing its trials, a completely different concept of a two-seat scout made its debut - the Bristol S.2A. A single-engine biplane with pilot and gunner seated side-by-side, it was inspired by the Scout D but, as a reliable synchronizer for a forward-firing gun was still awaited, the expedient of carrying a gunner alongside the pilot was adopted in the interest of keeping down the overall size of the aeroplane. The 110 h.p. Clerget provided the power initially in 7836 and 7837, the pair of prototypes. By the time that they were ready, one during May and the other during June of 1916, fairly adequate synchronizing gears were ready and the temporary solution provided by the S.2A was not required. Its performance was commendable and one of the two S.2As was modified for further trials with the lower power of the 100 h.p. Monosoupape Gnome.
In the course of September, 1915, design work had been initiated on an ambitious two-seat fighter biplane to be powered by twin engines and designated Bristol T.T. - Twin Tractor. Responsible for the project’s layout were F. S. Barnwell and L. G. Frise and in its general concept, together with the gunner in the nose and the pilot located behind the wings, the T.T. resembled the Vickers F.B.7 and F.B.8. The machine was of 53 ft. 6 in. span and was scheduled to employ a pair of 150 h.p. R.A.F.4a engines. Non-availability of these units forced the installation of two 120 h.p. Beardmores, the revision resulting in a new designation T.T.A. Two Lewis guns armed the front gunner and a third Lewis was installed for the pilot to fire to the rear. The T.T.A. was ready for its initial trials in May, 1916, and these were carried out by Capt. Hooper of the R.F.C.
   Like the two Vickers products, the Bristol T.T.A. lacked the primary requisites of a fighter and was too ponderous and low-powered to possess sufficient manoeuvrability, besides denying the pilot and gunner the quick communication between them which was so essential in a fighter. There was also negligible prospect of being able to fire the guns to the rear, which left the machine defenceless from that quarter; consequently, the pair of prototypes - 7750 and 7751 - were abandoned.
   The F.K.11 was not proceeded with but another design from Armstrong Whitworth, the three-seat F.K.5, also exhibited some equally remarkable features. It was built as the result of a War Office requirement for a multi-seat, long-range escort and anti-Zeppelin fighter, a specification to which Vickers and Sopwith also constructed prototypes.
   The Bristol F.3A, a development of the T.T.A., using its aft fuselage, biplane wings and tailplane and the 250 h.p. Rolls-Royce Mk.I for power, was proposed to the same requirement but was abandoned. To give the F.3A’s gunners unrestricted field of fire, they were going to be installed in a pair of cockpits incorporated in the upper wings.
The twin-engine Bristol T.T.A.
Two prototypes of an all-metal, two-seat fighter, designated M.R.1 and intended to eliminate the disadvantages attendant upon the usual wooden airframes under tropical conditions, were constructed following Barnwell’s basic layout for the project during July, 1916, with the detail design work undertaken by W. T. Reid. The engine chosen was the 150 h.p. Hispano- Suiza, the airframe that it powered being a two-bay biplane which was slightly larger overall than the F.2A and F.2B. The fuselage was mounted mid-way in the gap between the wings and was a stressed-skin monocoque covered with sheet aluminium. The pilot was provided with a single Vickers gun in the cowling while the gunner had a Lewis gun on a Scarff ring. Although tested comprehensively, the M.R.1 was not selected finally for production but is of note for its use of metal for the framework and the fuselage covering.
During the Summer of 1917 Bristol’s designer Frank Barnwell set to work on the design of a new single-seat fighter, the Scout F, to use the water-cooled 200 h.p. Sunbeam Arab II engine. The Scout F materialized as a single-bay biplane with N-type interplane struts and a very clean engine installation which was assisted materially by the location of the radiator between the undercarriage legs. Tests revealed excellent overall performance and flying characteristics bqt the Arab power plant persisted in giving trouble.
   Of the three Scout Fs constructed the third, B3991, was fitted with one of the new radial engines then beginning to appear. This was the 347 h.p. Cosmos Mercury with which B3991, redesignated Scout F.1, made its initial flight during April, 1918. The engine was installed to blend neatly into the F.1’s nose and, with it, the machine turned in a first-class performance, carrying armament of two Vickers guns on the front decking but development of the Scout F.1 was eventually halted.
As the War’s last days drew nearer Bristol’s F. S. Barnwell proceeded with his design for a two-seat fighter to take over from the F.2B. His first approach to a successor was started in November, 1917, as the F.2C with three alternative engines - the 230 h.p. Bentley B.R.2 rotary, the 260 h.p. Salmson radial and, finally, the 320 h.p. A.B.C. Dragonfly 1 - considered as the power unit. The Dragonfly was selected for the Badger Mk.I, as the F.2C was eventually named, and the prototype, F3495, was taken into the air for the first time on 4th February, 1919, by Capt. C. F. Uwins but crashed when the engine stopped suddenly owing to the failure of the petrol supply. The second Badger constructed, designated Mk.II, used the 450 h.p. Cosmos Jupiter radial with its greater power and reliability. The Badger was characterized by its single-bay, staggered, sweptback wings with their N-style interplane struts, and was armed with twin Vickers guns for the pilot and a Lewis for the observer. Three prototypes were built but no production ensued.
During 1910 there occurred one of those chance meetings which may sometimes have such far-reaching effects. F. M. Green engaged in conversation with Geoffrey de Havilland who, after having crashed his first aeroplane early in its tests, had constructed another and taught himself to fly on it. De Havilland told Green that, as the financial resources which he had had for pursuing his flying experiments were all but exhausted, it looked as though he might have to terminate such work. At Green’s suggestion, de Havilland applied to the Balloon Factory for a post as designer and test pilot. The outcome was that in December, 1910, he and his friend and assistant, F. T. Hearle, joined the staff of the Factory, taking with them to Farnborough the biplane for which the War Office paid £400. Although at the time it was evident neither to the authorities nor to de Havilland, in this way was the pioneer constructor enabled to carry on his work to such outstanding advantage in later years to the country, and to give immediate impetus to heavier-than-air development at the Factory by delivering to it a reasonably practical aeroplane. The Factory was so enamoured of its new acquisition that it bestowed on it the honour of the first official designation F.E.1.
   In design and execution de Havilland’s machine was, without exception, typical of the aeroplanes of the period. The layout was that of the successful Farman-style two-bay biplane with stabilizing and control surfaces carried on four booms fore and aft of the wings. The pilot’s position was the logical one on the leading edge of the lower wings, with the engine and its pusher propeller mounted behind him. Two main wheels and a tailskid formed the landing-gear and ailerons gave the machine its lateral control. The engine was the 45 h.p. unit which had been made to de Havilland’s design by the Iris Motor Company at Willesden. The entire framework of the biplane was of wood, the material resorted to by most of the constructors at the time. Its great virtue was that it was easily worked, without the necessity on the part of the impecunious flyers for any outlay on expensive tools or machines. Besides, wood was strong and cheap and easily repaired after the all-too-frequent mishaps which attended the attempts to stagger off the ground. The structure was braced with tensioned wire and covered with fabric.
Two months before the start of the War, the Royal Aircraft Factory parted with one of its most experienced and talented designers when Geoffrey de Havilland left in June, 1914, to work in the civilian industry by joining the design staff of the Aircraft Manufacturing Company at Hendon. Since being founded in 1912, Airco had been making aircraft which were not of its own design but its head, George Holt Thomas, was keen on setting up a design office so that the firm could establish itself as a company manufacturing its own designs.
   De Havilland’s first type for his new employers was to be a reconnaissance and fighting machine, perforce a biplane, and his success with the tractor B.E. series and the B.S.1 at Farnborough encouraged him to adhere to the same layout. The general form was evolving on the drawing board when it was realized by the War Office that there was still no practical means of firing a gun ahead through the propeller. Proposals for solving this problem had been submitted to the War Office by the Edwards brothers but had come to naught. The request was made that the tractor project should be abandoned and that a pusher layout be substituted.
   The revised machine was to be designed around the air-cooled 70 h.p. Renault V-8 engine and was to carry a front gunner in addition to the pilot. Although the new machine was by no means de Havilland’s first essay in design, it was designated D.H.1 and this and his succeeding types for the same company continued to be known by their designer’s initials, the name Airco being rarely applied as well.
   The D.H.1 exhibited a marked overall resemblance to the F.E.2 but was slightly smaller and heavier. One or two features of note were incorporated in an otherwise conventional two-bay pusher layout. These included a landing-gear embodying coil springs and oleo tubes for shock-absorbing, and a pair of aerofoil surfaces - some 3 ft. in span each - mounted on each side of the nacelle between the centre-section struts to act as airbrakes.
   On completion in January, 1915, de Havilland carried out the tests of the D.H.1 at Hendon. Its performance was reasonably good, although the Renault’s 70 h.p. was considerably lower than the 120 h.p. of the Beardmore which Airco had hoped would become available for it. Negligible effect was produced by turning the airbrakes through their 90° angle across the slipstream and drag was lessened when they were subsequently removed. The D.H.1 was forced to wait some time for its Beardmore engine as the few available went to the Royal Aircraft Factory. A number were built powered by the Renault and were fitted with cut-down sides to the gunner’s cockpit and undercarriages which reverted to rubber-cord springing. The production version built at King’s Lynn by Savages was designated D.H.1A, and benefited from the power of the Beardmore, the radiator of which was installed prominently immediately behind the pilot’s head. The gunner’s armament was a single Lewis gun on a pillar mounting in the nose, from which he had an excellent field of fire, and on some examples a Lewis gun was fitted for the pilot to fire over the gunner. In spite of its useful attributes, the D.H.1 never really got into its stride as a weapon of war as the F.E.2 was already well developed and the seventy-three D.H.1s and D.H.1As constructed were distributed mainly among Home Defence and training units, six of them finding their way out to the Middle East in 1916.
Prototype D.H.1.
While aerial activity over the Western Front steadily increased during the first half of 1915, in the Airco design office Geoffrey de Havilland was committing to the drawing-boards his concept of a single-seat armed scout of pusher layout, destined to be basically a smaller version of the D.H.1. Designated D.H.2 the machine was one of the cleanest and among the best-looking of pusher designs. The two-bay wing formula was adhered to, with the pilot seated well forward in the nacelle to command an excellent view in every direction. The 100 h.p. Monosoupape Gnome was chosen to power the D.H.2 which made its first flight in July, 1915.
   The sole object of designing the new pusher was to produce an effective fighting scout, the armament of which was a single Lewis gun pivoting on a mounting at the side of the cockpit. The intention was that the pilot should aim the gun by hand as needed, but production D.H.2s had the gun fixed in a central trough in the upper coaming of the nacelle, a location which assisted the clearance of possible stoppages. Construction was of wood throughout with the exception of the steel-tubing booms carrying the tail unit.
   In keeping with the machine’s intended role as a fighter, the performance was brisk and the generous control surfaces gave the D.H.2 great sensitivity, a quality which was extremely useful but which required careful handling and constant attention by the pilot. Among the hazards to be guarded against were unexpected spins and the catastrophic possibility of the rotary’s cylinders parting company with the crankcase and cutting through the tailbooms.
   The D.H.2’s great distinction is that it formed the equipment of the R.F.C.’s first single-seat fighter squadron, No. 24, a unit which arrived in France on 7th February, 1916, to be followed shortly by Nos. 29 and 32. The new fighter proved to be exceedingly useful and successful, doing great work in action for the two years following its introduction. Of four hundred D.H.2s produced, most used the standard engine but the 110 h.p. le Rhone also was employed as an alternative power plant.
An out-of-the-ordinary concept which did achieve fair success was Geoffrey de Havilland’s little D.H.5 single-seat biplane of 1916, unusual in that it incorporated back-stagger in pursuit of that much-sought-after feature of a fighter - a first class view for the pilot.
   Designed around the 110 h.p. le Rhone, the D.H.5 was in every other respect quite conventional in layout and construction. Unfortunately, performance at height was not a strong point with the type so, because of this fault, employment was found for it mainly in ground attack in which role the excellent forward view was a great asset.
In the Autumn of 1916 there appeared the first aeroplane to be both designed and constructed by the Fairey Aviation Company. Hitherto, the firm had built some Short-designed seaplanes but, with the F.2 three-seat, long-range fighter, it started the extensive line of aircraft which were to carry the name of Fairey for the ensuing forty years. The F.2 was intended for the R.N.A.S. and was a three-bay tractor biplane with a span of 77 ft. and a pair of 190 h.p. Rolls-Royce Falcon engines. Both gunners had Lewis guns on Scarff rings, one being in the nose cockpit and the other just aft of the wings.
   Although, when it flew in May, 1917, the single prototype 3704 showed the F.2 to be a competent enough design, it proved to be another of the early examples of that class of the large, multi-seat, multi-engine fighter which, owing to its inherent disadvantages, was to prove time and time again unsuitable for adoption and production.
J. D. North, designer to Claude Grahame-White’s concern at Hendon, tried his hand at a gun-carrier with the Type 6 Military Biplane which was ready in time for display at the 1913 Aero Show at Olympia. Designed on comparatively unorthodox lines, the machine was fitted with an Austro-Daimler engine mounted in the nose of the deep nacelle. The crankshaft was extended rearwards the length of the nacelle, where it was connected to the two-blade propeller by a chain drive. The propeller itself revolved around the upper tubular tail-boom which acted also as its bearing. This feature was reminiscent of the arrangement adopted in the Royal Aircraft Factory’s F.E.3 but the Type 6’s tail had the benefit of additional support from a pair of lower booms making in all a rigidly-braced triangular framework. The bore of the uppermost boom was used to carry the control wires to the rudder and elevators. Centre-section struts were omitted, the upper wings being carried across the nacelle by the inner interplane struts. Twin pairs of main wheels were suspended in slots in ski-shaped skids, and the nacelle carried two passengers on the sprung tops of the tool boxes on each side of the engine, the pilot being accommodated behind them. The Type 6’s single machine-gun was a Colt installed in the nose with 50 vertical and 180 horizontal field of fire.
Grahame-White Type 11 Warplane at Hendon in 1914.
Grahame-White Type 11 Warplane
1916 saw the appearance of another hopeful scout design from Grahame-White, the Type 20 single-seat biplane with the 80 h.p. Clerget. The machine embodied a neat, circular-section fuselage to which were fitted wings set with a pronounced gap. No progress was made with the Type 20.
   Despite its lack of success in obtaining orders for its previous scout designs, the Grahame-White Company tried once again with the Type 21 which was completed in April, 1917. The machine was a single-seat biplane, powered by an 80 h.p. le Rhone, in which every effort had been made to streamline the airframe and cut down drag. Single I-type interplane and centre-section struts braced the wings, to which ailerons were fitted to all four tips. Despite its attributes, which included a top speed of 107 m.p.h., the Grahame-White Type 21 was not adopted.
Two other single-seat fighters which were constructed during 1917 and remained prototypes only were the H.1 and H.2 designed for Mann Egerton and Co. by J. W. Carr to fall within the Admiralty’s N.1A requirement. Both were square-set, two-bay biplanes, fitted with the 200 h.p. Hispano-Suiza engine and armed with a single Vickers gun on the front decking and a Lewis gun on the upper centre-section. Intended for shipboard operations, the wings were made to fold, and N44 - the H.1 - carried external flotation equipment in the form of wing-tip floats as well as an under-fuselage float. The H.2 - N45 - utilized inflatable bags to provide its buoyancy. Although both machines were reasonably successful in their tests, neither version found official favour.
The biplane formula was sweeping strongly into favour and by 1914 had demonstrated its qualities undeniably in the Bristol Scout, Sopwith Tabloid and the Royal Aircraft Factory’s S.E.s. Biplane construction was stronger and lighter than that of the monoplane, and brought with it a brisk performance on the available power. However devoted to the monoplane its disciples might be, the only hope of obtaining production orders for a design lay in submitting to the requirements of the R.F.C., and developing acceptable biplane prototypes, whatever views a designer might hold concerning relative merits.
   The Summer of 1914, therefore, found Martinsyde abandoning the monoplane and busily engaged at Brooklands on a new design, the S.1, to the officially-approved biplane formula for a single-seat scout. When the machine made its appearance in the Autumn it was seen to present a completely conventional aspect and certainly possessed no features which could be classed as radical. Its 80 h.p. Gnome was fully and neatly cowled, the cooling air being admitted through a horizontal slot. Standard wooden construction was used throughout, with the usual fabric covering for the airframe.
   At first glance, with its single-bay wings and overall compact appearance, the S.1 appeared to be remarkably similar to the Tabloid but closer inspection revealed detail differences. At their forward extremities, the undercarriage skids incorporated small auxiliary wheels and the fuselage exhibited a higher fineness ratio compared with that of the Tabloid. The S.1’s wingtips possessed considerable outward rake and the complete tail unit outline set the pattern which was adhered to for all of the subsequent Martinsyde scouts. Martinsyde had also finally relinquished wing warping in favour of ailerons, of which four were fitted to the S.1. The original style of landing gear was subsequently replaced by a simpler form of normal V type. Despite its trim appearance the S.1’s performance was inferior to that of the Tabloid. The top speed of 87 m.p.h. was 5 m.p.h. lower than that of the Sopwith, a consequence of the slightly larger overall dimensions of the Martinsyde, and the S.1 was considered to be unstable longitudinally and to be bedevilled with poor response from its ailerons.
   The Martinsydes began to come off the production lines in late 1914 and, by the end of the year, eleven had been delivered. The S.1. had not found sufficient favour to be ordered to equip any complete squadron and the four which found their way to the Western Front served with Nos. 1, 4, 5 and 6 Squadrons, R.F.C., early in 1915. On 10th May, 1915, the S.1 which had been given a home by No. 6 Squadron provided high drama for its pilot, Capt. L. A. Strange. The machine had been fitted with a Lewis gun on the upper surface of the top centre-section to give uninterrupted fire over the propeller. The ammunition drum jammed after being emptied in attacking a German machine and, while Strange stood up to free it, the Martinsyde turned over into an inverted spin. Its pilot fell out, clinging for dear life onto the ammunition drum which, luckily for him, remained lodged in place. After losing several thousand feet of height, Strange managed to swing himself back into the cockpit, regained control and lived to tell the tale.
   The total estimated production run of the rather colourless Martinsyde S.1 was about sixty machines, such a small number that, had the type possessed any particular fighting virtues, it would hardly have been able to demonstrate them to any positive extent.
Martinsyde S.1.
While their S.1 was being produced in small numbers for the R.F.C., the Martinsyde design staff pressed ahead with a project by A. A. Fletcher for a long-range, single-seat fighter of good all-round performance. The new machine, designated G.100 and serialled 4735, was completed during the Summer of 1915, being designed around the reasonably powerful 120 h.p. Beardmore engine, driving a three-blade propeller. In common with its ancestor, the S.1, the G.100 found itself known as the Martinsyde Scout.
   Well-proportioned and purposeful in appearance it utilized the normal fabric-covered wooden structure of the era but several modifications were embodied in the production machines which appeared during the last days of 1915. The metal cowling over the engine was considerably neater, a two-blade propeller replaced the three blader and double flying-wires were installed.
   To enable the G. 100’s forward-firing Lewis gun to be used effectively, it was mounted on the upper centre-section at a height from which the line of fire would pass over the propeller. The only really unconventional feature about the G.100 was the second Lewis gun carried on a bracket on the port side of the fuselage just to the rear of the cockpit. This very odd arrangement was for the protection of the pilot who was expected to be able to perform the remarkable combined feats of flying the machine and firing blindly behind him with the second gun.
   To fulfil its mission as a long-range fighter, the G.100 had been designed purposely as a relatively large biplane with generous wing area to carry aloft sufficient fuel for a worthwhile endurance of 5-5 hours. Consequently in combat it was at a disadvantage compared with smaller, more agile contemporaries.
   On reaching the Western Front at the beginning of 1916, the G.100 was allocated to escort two-seaters of various squadrons, No. 27 Squadron, R.F.C., being the sole unit to be equipped completely with the Martinsyde G.100 and arriving at the battle front on 1st March, 1916. The fact that it was a useful weight-lifter was quickly recognised and the G.100s found themselves soon adapted as bombers.
   An improved version of the Martinsyde G.100, the G.102, appeared during 1916, benefiting by the extra 40 h.p. available from its 160 h.p. Beardmore engine and taking to itself the name Elephant. Experimental armament installations on Elephants included one with a Lewis gun to starboard of the cockpit and firing upwards at about 45° through the centre-section and another which was used during the Summer of 1917 in trials with the Eeman gun gear. The Martinsyde G.100 and G.102 carried out some of their most redoubtable work in the Middle East and the memory of the Elephant has been carried forward as the symbol in the badge of No. 27 Squadron, R.A.F.
Martinsyde G.102 Elephant photographed at Brooklands.
At Brooklands Martinsyde had been busy building a new single-seat biplane fighter, the R.G., which was of single-bay layout and smaller than the Elephant but on generally similar lines. Powered by the 190 h.p. Rolls-Royce Falcon and armed with two Vickers guns on the front coaming, the R.G. exhibited the hallmark of a first-rate and competent fighter design. Tests at Farnborough during February, 1917, revealed a fine performance but, as both the Camel and S.E.5 had by then been adopted as replacement fighters and the Falcon was needed for Bristol Fighters, the Martinsyde R.G. unfortunately came to naught.
Mid-1917 saw the debut of a two-seat fighter, the F.1, from Martinsyde at Brooklands. The machine was odd in carrying its observer in the front cockpit where he could do little that would be effective in combat. A 250 h.p. Rolls-Royce Mk.III powered the F.1, giving it a top speed at 6,500 ft. of 109-5 m.p.h. A two-bay biplane of normal appearance and construction, the F.1 had little to recommend it in its original form but Martinsyde made another effort at producing a two-seat fighter reconnaissance machine when they completed their F.2 biplane in May, 1917. <...>
A two-bay biplane of normal appearance and construction, the F.1 had little to recommend it in its original form but Martinsyde made another effort at producing a two-seat fighter reconnaissance machine when they completed their F.2 biplane in May, 1917. A 200 h.p. Hispano-Suiza engine gave it a top speed at ground level of 120 m.p.h., the F.2 being armed with a single Vickers gun for the pilot and a Scarff-mounted Lewis for the gunner. Although a competent enough design in most respects, the indifferent view for the pilot told against the F.2 and it stood little chance of filling the place occupied by the competitive Bristol F.2B.
Following the lack of success with their F.1 and F.2, Martinsyde abandoned the two-seat formula for a fighter and turned with hope to the single-seater again as a proposition likelier to yield more positive results.
   The F.3 was ready for testing by November, 1917, and lived up to its parent firm’s expectations. An eminently compact, clean single-bay biplane, it was powered at first by an experimental Rolls-Royce Falcon which delivered 285 h.p., resulting in a useful maximum speed at ground level of 142 m.p.h. and a service ceiling of 24,000 ft. Two Vickers guns fired forwards from beneath the cowling. Martinsyde had the satisfaction of knowing that, according to official reports, in the F.3 a machine had been designed which was considered to be superior to any other contemporary single-seat fighter. The following year production got under way as the F.4, incorporating minor alterations.
   By June, 1918, the revised production version of the Martinsyde F.3, designated F.4 and named the Buzzard, was ready for its trials, powered by the 300 h.p. Hispano-Suiza engine. In the Buzzard an improvement in the view for the pilot was effected by moving the cockpit a short distance to the rear. In trials during August, 1918, following the fitting of improved pistons to the engine, the Buzzard Mk.I recorded a maximum speed at ground level of 144-5 m.p.h., earning itself the distinction of being the fastest type of British aircraft in production when the War ended. The machine’s all-round excellence resulted in good orders for it to re-equip fighter squadrons and included a long-range version - the Mk.Ia. However, production was unable to get under way sufficiently during the few remaining months of the War for the Buzzard to enter service and the machine, in view of its fine qualities and advanced conception, was unfortunate in not being selected to continue the single-seat fighter tradition in the peacetime Royal Air Force.
D4263, a Martinsyde F.4 Buzzard.
Among the companies engaged in sub-contract aircraft work was the firm of F. C. Nestler, Ltd., and near the close of 1916 they constructed a manoeuvrable 100 h.p. Monosoupape Gnome-powered single-seat biplane scout to the designs of Mons. Boudot. The Nestler Scout was quite conventional in conception but was abandoned after it crashed at Hendon on 26th March, 1917, while being flown by J. B. Fitzsimmons who lost his life in the accident.
During 1917 Farnborough’s brilliant fighter designer H. P. Folland had vacated his position at the Factory and joined the Nieuport and General Aircraft Co. Ltd., at Cricklewood, where he was soon responsible for the firm’s first original design, the B.N.1, which was started early in 1918. As was to be expected from the Folland drawing-board, the resulting single-seat fighter was a workmanlike design with clean and appealing lines. Although stagger was employed widely to improve view, it was not embodied in the B.N.1’s two-bay cellules and another unusual feature, which Folland had used on his earlier S.E.4, was the fitting of single I-type interplane struts. The normal fuselage-mounted twin Vickers guns were augmented by a single Lewis gun on the upper centre-section. The B.N.1, wrecked in a crash on 10th March, 1918, was designed to use the 230 h.p. Bentley B.R.2 and displayed a vertical tail outline which revived the shape employed on the S.E.2a and S.E.4.
Two further single-seat fighters were planned under the R.A.F. Type 1 conditions. These were the Armstrong Whitworth Ara and the Nieuport Nighthawk but neither machine was ready before the beginning of 1919.
   In the design, H. P. Folland succeeded in raising the standard of his art as a single-seat fighter designer to a new level in laying out a two-bay biplane which displayed excellent proportions and looked every inch a fighter. In flight, the Nighthawk’s behaviour was in every way compatible with the promise inherent in its appearance. Handling characteristics and performance figures were admirable, including a top speed of 151 m.p.h. at ground level and a service ceiling of 24,500 ft. The Nighthawk was given what had become the standard armament of twin fixed Vickers guns. Large-scale production of the machine was ordered even though it was powered by the Dragonfly radial but the unfortunate vicissitudes which attended the engine curtailed any chance of widespread service for it.
   A decision was made during 1920 which was to have in the future a momentous effect, unforeseen at the time, on the subsequent development of the British single-seat fighter. This was the agreement among the directors of the Gloucestershire Aircraft Co. of Cheltenham to continue in business as aircraft manufacturers despite the lack of potential orders. The Company’s experience of aeroplane manufacture originated during the War when H. H. Martyn of Sunningend undertook at first sub-contract component work, finally progressing to producing complete aeroplanes of de Havilland and Bristol design. The firm was noted particularly for the outstanding workmanship put into its aircraft and set about continuing its aspirations by acquiring the designs of the Nieuport and General Aircraft Company when that firm closed down at Cricklewood in 1920. Of substantial advantage to Gloucestershire in the project was that the British Nieuport chief designer, H. P. Folland, agreed to join the firm. Under this set of circumstances there was set in motion the production of a long line of excellent fighters from Cheltenham and Gloucester originating in the gifted brain of Folland.
   The Dragonfly-engined Nighthawk was shown at the initial R.A.F. Pageant at Hendon on 5th July, 1920, but, for the time being, no sign was forthcoming from the Air Ministry of interest in promoting and encouraging new designs in fighters for the Royal Air Force. Foreign governments, however, were keen on building up air arms for themselves, having witnessed what strength could be wielded by the air forces of the belligerent powers in the late war. Consequently, a batch of fifty modified 230 h.p. Bentley B.R.2-powered Nighthawks, under the original name of Mars Mk.II, Mk.III and Mk.IV but redesignated Sparrowhawk Mk.I, Mk.II and Mk.III respectively, were sold to the Imperial Japanese Navy, thus providing the firm in 1921 with its first fighter contract.
Nieuport Nighthawk (Jupiter)
The sense of urgency which rose above all other considerations manifested itself in many ways on the home front. One of those who were immediately affected was the remarkable Noel Pemberton Billing who, after several years of experimenting with various landplane designs, had veered towards the development of marine aircraft. Always a thinker on extremely original, but at the same time practical, lines of approach he had, in June, 1914, finally formed a limited company under his name at Woolston, Southampton, to manufacture his designs. As soon as war became inevitable, Pemberton Billing drew up at top speed his concept of a single-seat scout and built the machine at once. To enable it to be produced quickly in the necessary quantities envisaged, the P.B.9 was designed on lines of the utmost simplicity around the 50 h.p. Gnome engine. The sole prototype was rushed through the works at the beginning of August to completion in eight days, out of which the actual construction took a week, after which phenomenal performance it was known naturally as the Seven-Day Bus.
   The P.B.9’s appearance could not have been less like that of its immediate predecessor, the P.B.7 single-seat flying-boat, the sleek lines of which made the machine one of the most advanced in design practice at the 1914 Olympia Aero Show. The box-like fuselage of the Seven-Day Bus exhibited stark utility in its form in sharp contrast with the exquisite contours of the P.B.7’s hull. The 26 ft. span wing panels of the P.B.9 bore out the theme of unrestrained simplicity, being square-cut, of constant chord and each in one piece. The lower set were taken straight across underneath the fuselage to be bolted direct to it. On the power of a 50 h.p. Gnome Victor Mahl flew the P.B.9 at Hendon, where it was successful enough to spend its life as a trainer for R.N.A.S. pilots. Even though the R.F.C. and R.N.A.S. were so critically short of scouts when they were plunged into war, Pemberton Billing’s remarkably inspired effort at filling the gap so adroitly was wasted as the machine was not ordered into production. Although this was the case, the little P.B.9 scout deserves a corner to itself in the annals of fighter development as one of the very earliest examples of the inexpensive, quickly-built, utility type which came to be known in later years as the light fighter.
Scout biplane PB9 later PB13 was built in seven days in August 1914, was tested at Netley and Brooklands and taken over by the RNAS.
Among the assortment of pusher scouts hopefully produced by various concerns, there appeared in 1915 a single-seater from the drawing-board of Noel Pemberton Billing. A single-bay biplane, powered by the 80 h.p. le Rhone, the P.B.23E was a sprightly-looking machine, with the pilot seated in a finely-formed, metal-covered nacelle suspended between the wings at midgap and containing the single Lewis gun in its nose.
   The P.B.23E, soon known from its appearance as the Sparklet or Push-Proj, made its first flight at Hendon early in September, 1915, following which the Admiralty placed an order for twenty of a modified version as the Pemberton Billing Scout.
   The revised model, designated P.B.25 by the designer, used wings of swept-back form in place of the straight-edged original style, and the former metal-covered nacelle was replaced by a new one enclosed in fabric. Increased power was provided by the installation of the 100 h.p. Monosoupape Gnome engine and the Lewis gun was raised to a far more accessible position in the top of the fore-decking of the nacelle. The first of the P.B.25s, 9001, received a slight increase in power over the remainder of the batch by having a 110 h.p. Clerget fitted.
   Despite its competent performance, which included a top speed of 89 m.p.h. with the Monosoupape Gnome, and its advanced conception, the P.B.25 is not known to have been engaged in any operational role.
Pemberton Billing P.B.23E.
One of Noel Pemberton Billing’s particular concerns was the lack of effective defence against the stealthy, cloud-wrapped menace of the Zeppelins. His logical and inventive mind formulated several requirements as an antidote which were transformed during 1915 into the P.B.29E, a remarkable pusher quadruplane. As an aid to good climb performance, the wings were of particularly high aspect ratio and were expected also to bestow a minimum speed of 35 m.p.h., a feature designed to contribute to endurance while on patrol, to assist materially in operating the machine in the very primitive conditions under which night flying was then taking place, and also to provide a steady gun platform. The gunner, standing in a streamlined enclosure between the two uppermost pairs of wings, had an outstandingly good all-round 360° field of fire. The two-bay wings each bore a pair of ailerons and the two 90 h.p. Austro-Daimler engines, driving four-blade propellers, were mounted on the underside of the lowest-but-one pair of wings which joined the fuselage level with the top longerons. Two pilots were carried in tandem cockpits; to the rear of the aft cockpit the fuselage section became triangular and terminated in a tail assembly with biplane horizontal surfaces and triple fins and rudders. A sense of urgency in the Woolston works drove the P.B.29E through to completion in some seven weeks from the start of the design but the machine’s life was short as, after being flown at Chingford, it was wrecked in a crash at the same place.
1916 saw the completion of another of Noel Pemberton Billing’s unusual designs - the Supermarine Night Hawk. The project had started the year before, following the appearance of the P.B.29 quadruplane and the Admiralty’s decision to investigate the inventor’s claims for his concept for anti-Zeppelin warfare. Pemberton Billing was enabled to set about designing the machine in 1915 by the agreement of the Admiralty to his release on indefinite leave for the purpose from the R.N.A.S. in which he was serving as a Flight Lieutenant.
   The Night Hawk, when it saw the light of day, was a truly extraordinary creation. Once again, the quadruplane layout was followed but with sweptback wing panels in the three-bay structure. The pilot was seated in a generously-glazed enclosed pylon structure, which reached above to the upper wings and also carried the top front gunner with his 1-5-pounder Davis. To his rear was a position for a Lewis gun on a Scarff ring and the nose of the fuselage terminated in another cockpit containing a Scarff-mounted Lewis gun. Both of the machine-gun locations were provided primarily for the machine’s own defence. Forward of the front Lewis gun position was a searchlight which received its power from a generator driven by a 5 h.p. A.B.C. engine, the complete unit being installed in the nose.
   The Night Hawk embodied many other ingenious and advanced features but was provided with comparatively low power from a pair of 100 h.p. Anzani engines which were given the onerous task of coping with a wing span of 60 ft. and a loaded weight of over 6,000 lb. C. B. Prodger carried out the initial flights of the sole Night Hawk 1388 at R.N.A.S. Eastchurch and established the machine’s top speed to be 75 m.p.h. and its landing speed the aimed-for 35 m.p.h. Substantial endurance of 9 hrs. normal and 18 hrs. maximum was part of the machine’s patrol capabilities.
   During the gestation period of the Night Hawk, Pemberton Billing relinquished his part in the control of the company which bore his name and the machine finally emerged from the newly-formed Supermarine Aviation Works, Ltd., under Hubert Scott-Paine.
   Despite its many advanced features, the Night Hawk remained a single prototype but, during the same period, the Sopwith Company was engaged on a comparably unusual design which was destined for fame and success. Supermarine’s quadruplane was unable to make the grade but the Sopwith Triplane’s attributes were such that it soon established itself favourably in service.
During the early part of 1916 Sqn.Cdr. J.W. Seddon, one of the early pioneers of British aviation, was stationed at Port Victoria on the Isle of Grain and was responsible for the investigations which resulted in the construction of the Port Victoria P.V.1. This was an attempt at improving the performance of the Sopwith Baby seaplane, particularly as far as its weight-lifting qualities were concerned. As with any service aeroplane, the tendency was to continue adding more equipment to the steady deterioration of performance.
   The standard Baby’s wings were of the popular low thickness/chord type with comparatively little camber. This form of aerofoil gave low drag but possessed accompanying low lift properties. National Physical Laboratory experiments on aerofoil sections with greater camber had shown them to be superior for general weight lifting but a loss of speed was the penalty. Sqn.Cdr. Seddon decided to put the Laboratory investigations to practical test and had a Sopwith Baby modified by fitting a standard fuselage with new wings of identical area but with increased aspect ratio and of heavily-cambered profile. Forward stagger was also increased and new larger floats were installed. The finished conversion weighed some 300 lb. more than the normal Baby but was quite successful in proving that the revised wings enabled the P.V.1 to lift greater loads. With the 100 h.p. Monosoupape Gnome the top speed was 77 m.p.h. and the height reached was in excess of 8,000 ft. The P.V.1 later contributed to early experiments related to possibilities of launching by catapult in the course of which it took off from a railway truck on the Isle of Grain.
   The R.N.A.S. Experimental Construction Depot at Port Victoria was now getting into its stride and followed up the P.V.1 conversion with a completely original design, the P.V.2, for a Zeppelin-intercepting seaplane, single-seat gun-carrier. The armament selected was the Davis 2-pounder with ten rounds and further stipulations were that the top speed was to be 80 kt., operational cruising height 10,000 ft. and endurance 3 hours.
   The P.V.2 was drawn up around the 100 h.p. Monosoupape Gnome, enveloped by a broad-chord cowling, from the periphery of which the fuselage section tapered smoothly to the tail end. The upper wings were mounted direct onto the top longerons, to avoid obstruction of the pilot’s view by struts, while the narrow-chord lower planes passed in one piece well below the underside of the fuselage. Rectangular-section pontoon-type floats were fitted but were changed later for the more refined style of Linton Hope float.
   The P.V.2 N.1 presented an altogether extremely attractive appearance for its time, and during its first flight tests in June, 1916, flew successfully with the exception of the aileron control. This fault was rectified by shortening the original broad-span ailerons to half their span and with strengthening them. The P.V.2 was not destined to adhere to the original project of operating with the Davis gun as development of the weapon was terminated.
   Rather than abandon the P.V.2 altogether, the machine was rebuilt as the P.V.2bis with the upper wings elevated by 1 ft. on struts, together with the addition of a 2 ft. centre-section, so that they passed over the fuselage and thereby improved the forward view for landing. As a seaplane fighter the P.V.2bis was scheduled to carry a pair of Lewis guns above the upper centresection but apparently only one was fitted eventually.
Admiralty interest in fighters continued to increase with the result that, during the first months of 1916, the Port Victoria designers received a request from the Experimental Armament Section for a two-seat fighter layout required to be an effective gun-carrier.
   Plans were commenced for a pusher project on a land undercarriage and powered with the 110 h.p. le Rhone. It would seem that this machine would have been the P.V.3 but the project did not reach fruition and was dropped in favour of a revised development on floats. This was designated P.V.4 and given the serial N8. An American-designed engine, the 10-cylinder Smith Static radial which delivered 150 h.p., was scheduled to power the P.V.4. Based on the output of this engine, the specification included a top speed of 80 kt., an initial climb rate of 5,000 ft. in 15 min., an endurance of 8 hours, wireless equipment and a Lewis gun for the gunner. The crew of two were housed in a trim, streamlined nacelle, to the top longerons of which were fitted the upper wings. The lower wings were considerably smaller than the upper set and the tail unit was carried on four slim booms. Stepped Linton Hope main floats formed the landing-gear, together with a single tail float, and a Scarff ring in the nose was used to enable the gunner to make the best use of an outstanding field of fire for his gun. The Smith Static, being produced in Britain by Heenan and Froude, was extremely slow in reaching production status, so that by the time that the P.V.4 was ready for its power unit in the Autumn of 1916 the Static was still not available. After continuing delay, a final effort was made in mid-1917 to get the P.V.4 airborne by installing a 110 h.p. Clerget. The Clerget’s greater length upset the balance of the machine completely and only considerable revision of the design could have rectified the faults. By this time the cleaner tractor with its synchronized forwards-firing gun was in the ascendant and development of the P.V.4, commendable design though it was, was dropped.
During 1917 the Admiralty’s Air Department continued to request designs from the R.N.A.S. Experimental Construction Depot at Port Victoria on the Isle of Grain, the P.V.4 being followed by a single-seat fighter seaplane which was to encompass also the role of light bomber. Two versions were built - the P.V.5 N53 sesquiplane and the P.V.5a with wings of equal span. Floats of Linton Hope style were intended to be used and the engine scheduled was the elusive 150 h.p. Smith Static which was late in arriving for the pair of prototypes.
   Finally, the 150 h.p. Hispano-Suiza was installed in the P.V.5 and the machine was mounted on floats of refined pontoon style. Its companion P.V.5a was fitted with the more powerful 200 h.p. Hispano-Suiza and received the intended Linton Hope floats. Each machine was armed with a single Vickers gun in front of the cockpit. Both machines were quite successful in their trials but neither was considered to be required for production.
Port Victoria P.V.5 N53.
The next designation in the Port Victoria design series, P.V.6, was allotted to an uncompleted project for a fast scout landplane. Attention was next turned to meeting a call for a very small, low-powered scout capable of being flown from minor warships. The engine specified was the two-cylinder, geared 45 h.p. A.B.C. Gnat. Besides the Port Victoria Depot, the Experimental Flight at Eastchurch was asked also to submit a design.
   Each machine was a diminutive biplane, that designed at Port Victoria being designated the P.V.7, while the Eastchurch-conceived machine, through transference to Port Victoria for completion, became the P.V.8. Respectively, the aircraft were called the Grain Kitten and the Eastchurch Kitten.
   Both types constituted early examples of the often-attempted light fighter, each being a well-conceived and competent approach to an interesting challenge.
   Grain’s P.V.7 was the smaller of the two, following the normal layout for a single-seat, single-bay biplane of unequal span and showed traces in its outline of its predecessors from the same design source.
   The Eastchurch Kitten was rather more angular and of cleaner cut than the Grain machine and received equal-span wings, set with accentuated stagger on single I-type interplane and centre-section struts.
   Both the P.V.7 and P.V.8 were forced to use the lower output of the direct-drive 35 h.p. A.B.C. Gnat as the 45 h.p. version of the engine was not available. Each was armed with a single Lewis gun on the upper centre-section and each machine was modified in several respects after completion in mid-1917 and, of the pair, the P.V.8 showed itself to be the superior aeroplane.
The next designation in the Port Victoria design series, P.V.6, was allotted to an uncompleted project for a fast scout landplane. Attention was next turned to meeting a call for a very small, low-powered scout capable of being flown from minor warships. The engine specified was the two-cylinder, geared 45 h.p. A.B.C. Gnat. Besides the Port Victoria Depot, the Experimental Flight at Eastchurch was asked also to submit a design.
   Each machine was a diminutive biplane, that designed at Port Victoria being designated the P.V.7, while the Eastchurch-conceived machine, through transference to Port Victoria for completion, became the P.V.8. Respectively, the aircraft were called the Grain Kitten and the Eastchurch Kitten.
   Both types constituted early examples of the often-attempted light fighter, each being a well-conceived and competent approach to an interesting challenge.
   Grain’s P.V.7 was the smaller of the two, following the normal layout for a single-seat, single-bay biplane of unequal span and showed traces in its outline of its predecessors from the same design source.
   The Eastchurch Kitten was rather more angular and of cleaner cut than the Grain machine and received equal-span wings, set with accentuated stagger on single I-type interplane and centre-section struts.
   Both the P.V.7 and P.V.8 were forced to use the lower output of the direct-drive 35 h.p. A.B.C. Gnat as the 45 h.p. version of the engine was not available. Each was armed with a single Lewis gun on the upper centre-section and each machine was modified in several respects after completion in mid-1917 and, of the pair, the P.V.8 showed itself to be the superior aeroplane.
The tiny Port Victoria P.V.8 Eastchurch Kitten.
Last of the Port Victoria series of original fighter designs was the P.V.9, a single-seat 150 h.p. Bentley B.R.I-powered sesquiplane seaplane which was completed in the last month of 1917. Two machine-guns were carried, a fuselage-mounted Vickers and a Lewis on the upper centre-section. The sole prototype, N55, proved to possess fine all-round qualities and was considered to out-perform any previous design in the same category. Despite these attributes, an ultimate lack of demand resulted in the abandonment of the P.V.9.
Since the days when it had been the Balloon Factory, the Army Aircraft Factory had naturally, in its daily association with the military aspect of aeronautics at Farnborough, been conscious of some degree of war potential in the aeroplane and had experimented accordingly with wireless and photography. Eventually, it was realized that an aeroplane reconnoitring enemy positions might need to carry its own defensive armament, and to test such an installation a Maxim free-firing machine-gun was fitted on a simple mounting in the nose of the nacelle of the F.E.2 biplane during 1912. The F.E.2 was originally the F.E.1 which had been reconstructed in 1911 with modifications following its crash during the Summer of the same year while being flown by Lt. T. J. Ridge, then the Factory’s Assistant Superintendent. The Iris engine had been replaced by the popular 50 h.p. Gnome and crew comfort was improved by the addition of a two-seat covered nacelle projecting in front of the lower wings.
   The way ahead to the evolution of the armed scout was clearly opening up. Successful tests throughout the year prompted yet another rebuilding of the long-suffering F.E.2, and early in 1913 the machine was completely redesigned and reconstructed as a two-seat gun-carrier of greatly refined aspect compared with its earlier appearance. The former crude, slab-sided nacelle had given way to a new structure of far cleaner and pleasanter aerodynamic form with good protection for the tandem-seated crew. Behind them was the increased power of a 70 h.p. Renault engine driving a four-blade propeller. The well-rounded plan-form of the B.E.2a was evident in the new outer wing panels and the entire tail unit had been revised, attention being paid also to cleaning up the landing gear. The gun mounting in the nose had been improved and, altogether, the new F.E.2 presented an extremely workmanlike appearance. The alterations had brought the span up to 42 ft. and increased the loaded weight by 50%. The top speed also had been improved to 67 m.p.h. The machine continued to be flown for the rest of the year but its end came abruptly on 23rd February, 1914, when it crashed near Wittering while being flown by Ronald Kemp, with fatal consequences to the other occupant, E. T. Haynes. The cause of the accident was ascertained to have been lack of fin area to balance the forward side area which had increased when the new enlarged nacelle had been fitted. Nevertheless, the F.E.2. had served the Factory well and had proved to be very good value at the £400 which the War Office had paid originally for it. In its final metamorphosis the machine played the part of the progenitor of the Fighting Experimental series of pusher biplanes the first of which, the F.E.2a, had been designed at the Factory during August, 1913, some six months before the F.E.2’s demise.
Meanwhile, the Royal Aircraft Factory had been extremely fortunate in attracting to its staff some of the best brains in the new science. The scope of technical investigation had increased steadily with the improvement in facilities for research, and sufficient practical experience had been accumulated to enable the staff to undertake the design and construction of a small but, for the era, remarkably advanced series of scouts.
   The first outcome of this new line of investigation was the B.S.1, designed by Geoffrey de Havilland during 1912 and completed early in 1913. Considering that the machine was drawn up such a short time after consistent and reasonably reliable flying had become commonplace in Britain, it was an extraordinary and brilliant example of swift progress and advanced applied aerodynamics. Gone was the simple rectangular-section fuselage which had so far been the accepted thing. In its place was a finely-contoured, wooden monocoque structure with the engine cleanly blended into the circular section under a neat metal cowling. Originally the fourteen-cylinder, two-row 140 h.p. Gnome was chosen but substituted was the less-powerful ten-cylinder two-row 100 h.p. Gnome. The B.S.1’s elegant form was that of a tractor biplane with well-staggered single-bay wings, this last feature - in company with cutouts at the upper and lower centre-sections - being incorporated to give the pilot the best possible view from his well-shielded cockpit. Streamlined bracing-wires, known as Raf-wires, were Factory developments and were used on the scout. The shape of the wingtips and the tail unit showed that the B.S.1 had its ancestry in the B.E.2 and B.E.3.
   The machine, the first in line of all single-seat scouts, was tested by de Havilland during March, 1913, but, in his hands, crashed in the same month. Before the accident, however, tests revealed an excellent performance, including a top speed of 91’4 m.p.h. over a measured course, a climb of 900 ft./min. and an endurance of 3 hours. The mishap, which gave the pilot a broken jaw, was the result of faulty side area balancing, a part of the art of design which was then still rather a mystery.
Although, in the straightforward two-bay pusher biplane layout of the F.E.2, the Factory’s designers had played safe by following a formula which was by then well proven, tne next machine to be built within the Fighting Experimental category, the F.E.3, displayed an innovation which was a startling departure from the conventional. Designed primarily as a gun-carrier with a crew of two, it appeared at Farnborough in 1913. With a span of 48 ft. and a loaded weight of 2,100 lb., the machine was larger and heavier than its predecessor, the F.E.2. Stagger had been introduced in the wing cellules and the nacelle enclosed the 80 h.p. Chenu engine which received its supply of cooling air by way of the circular nose orifice. The four-blade propeller was mounted at the rear end of the nacelle and was remarkable in that it revolved around the single metal tubular boom which carried the tail surfaces and which replaced the structure of a quartette of braced wooden booms normally utilized for the purpose. The wheel and skid undercarriage was quite conventional. The F.E.3’s alternative designation was A.E.1, a title which is likely to have indicated Armed Experimental in view of the aircraft’s intended purpose. The Coventry Ordnance Works 1-5-pounder quick-firing gun was mounted inside the nacelle to fire its shells through the nose opening, trials of the installation being carried out during the Summer of 1913 in the single example built of the F.E.3.
   While the opening scenes of the conflict were being enacted on the Continent, at Farnborough the Royal Aircraft Factory’s designers were deeply involved in new projects in the midst of the greatly accelerated programme thrust on their resources in the strident urgency of war. Several Fighting Experimentals were numbered among their proposals and incorporated some widely diverse ideas in layout.
   The two-seat F.E.6, built in 1914, carried on the unusual theme demonstrated in the F.E.3 of the tail unit being borne on a single metal tubular boom which passed through the pusher propeller’s boss. The F.E.6 had the more powerful 120 h.p. Austro-Daimler for power and the layout again provided the gun with uninterrupted forward fire. As was the case with the majority of what might be classed as freak designs in search of the ideal, the F.E.6 was too radical to be successful as an operational machine and failed to be ordered for production.
The B.S.1’s fiat spin had damaged it but rebuilding was put in hand with particular attention to the tail unit. This was given small fins above and below the fuselage, a larger rudder of entirely new design and divided elevators in place of the former one-piece type. The engine was altered to a nine-cylinder 80 h.p. Gnome matched by a propeller of smaller diameter and finer pitch. On leaving the workshops the machine was redesignated B.S.2 for a short while but this was then changed to S.E.2. to signify Scouting Experimental in keeping with the aircraft’s avowed duty, and was in line with the revision of S.E. from the old Santos Experimental used solely for the ill-fated tail-first S.E.1.
   Despite a lower speed of 85 m.p.h., the S.E.2 was found to be a superior flyer in its new form and its sprightly performance, unmatched by any of its contemporaries, earned it the soubriquet of the Bullet.
   Continued flying of the machine encouraged further development and once again, during 1913, the S.E.2 went under cover to be brought into the open after its metamorphosis as the S.E.2a. The after portion of the fuselage monocoque had been replaced by a fabric-covered former and stringer structure terminating at the rear in a revised tail unit with larger fin and rudder, the alterations being accompanied by a slight reduction in weight.
   The solitary S.E.2a, which had belonged to No. 5 Squadron of the R.F.C., found itself part of No. 3 Squadron at Moyenneville in France in October, 1914, where it flew armed with the pilot’s .45 cal. revolver and also with a rifle fitted at an angle on each side of the fuselage to fire outside the propeller. Its high speed gave it clear superiority over any of the enemy’s aircraft but the S.E.2a remained at the Front for some six months only, returning to England during March, 1915, a lonely machine of brilliantly advanced design at the time of its conception and which deserved a far better fate than it received.
8294, a single-seat night fighter version of the B.E.2c, built by Grahame-White.
But new equipment was on the way. Some sixteen months earlier, in August, 1913, the Royal Aircraft Factory had drawn up a two-seat pusher biplane as an original fighter design from the outset. Designated F.E.2a it remained an unbuilt project until the war started. The War Office then decided that the R.F.C. needed a potent fighter immediately and ordered twelve from the Factory. Some five months elapsed before the prototype F.E.2a was ready in January, 1915, and when it appeared it could be seen that the new machine had lost the fairly shapely lines which had graced the last version of the F.E.2. The F.E.2a, with its three-bay 47 ft. 9 in. span wings, enlarged nacelle and sturdy oleo undercarriage, was a pugnacious, hefty-looking machine powered with a 100 h.p. Green engine driving a two-blade propeller. The Green was shrouded by a metal cowling and the pilot was raised well up in his cockpit so that he could see comfortably over the observer in front of him. Between the tail booms the trailing edge of the upper wings was hinged so that, aft of the rear spar, it could be turned down to function as a landing flap. The pair of skids on the undercarriage converged at the front to carry a small third wheel as a nose-over preventative. Although the Green power plant had been exceedingly useful a few years previously in getting many different early machines into the air, its comparatively low power/weight ratio told against it in a type which, for its role, demanded the best possible performance.
   Within two months, in March, 1915, a revised version using the more powerful 120 h.p. Beardmore appeared and was redesignated F.E.2b. The new engine was mounted without a cowling and another alteration was the deletion in the F.E.2b of its predecessor’s airbrake. Although the need was so great, production was extremely slow in getting under way and it was not until another eight months had passed that the initial order for twelve was completed. The first arrived in France on 20th May, 1915, for use by No. 6 Squadron but it took a further four months to enable the unit to muster but four F.E.2bs. As a design, therefore, the F.E.2b was more or less obsolescent by the time that it started flying over the lines but, none the less, proved itself a very useful type.
   Even though the pusher layout had patently had its day by mid-1916, the F.E.2b continued to soldier on and was revised in two examples, designated F.E.2c, which were built as night-fighters; the main alteration was that the pilot’s cockpit was the front one.
   Following the pair of F.E.2cs came the F.E.2d, which set out to achieve better performance by using the excellent new 250 h.p. engine from Rolls-Royce, the first of a magnificent line of peerless aero-engines from the same firm.
   Later to receive the name of Eagle, the 250 h.p. Rolls-Royce had been designed during 1914 by Henry Royce and his chief assistant A. G. Elliott. The intended rating was 200 h.p., but on test in October, 1915, under six months from the time drawings were commenced, the twelve-cylinder water-cooled engine gave 225 b.h.p. Further development produced 266 b.h.p. by March, 1916, 284 b.h.p. by the following July and 322 b.h.p. by the end of the same year.
   In the F.E.2d the Eagle gave the two-seat pusher fighter an extended lease of life and the new machine arrived in France in time for the operations during the Battle of the Somme which started at the beginning of July, 1916. Unfortunately, owing to the landing of the first F.E.2d to be sent to France on 30th June in German-held territory, the potentiality of this latest arrival at the Front was revealed to the enemy before it went into action. Notwithstanding, in spite of its obsolescence as a concept and its bulk and clumsy appearance, the F.E.2d gave valiant and untiring service. The type was used to undertake varied experiments in armament and attempted also to intercept Zeppelins but its efforts to aid Home Defence were not conspicuously successful.
F.E.2b, doughty opponent of German scouts.
However, the Royal Aircraft Factory’s staff had not been idle and in June, 1914, revealed a successor to the S.E.2a. A projected modification of the S.E.2a, the S.E.3, was dropped and the Factory went ahead to construct the S.E.4 designed by H. P. Folland, a man destined to play an ever-increasingly important part in British fighter design for many years afterwards.
   In the S.E.4 he produced a fast, unarmed scout embodying the very latest advances in aerodynamic practice. To reduce drag to the absolute minimum the fourteen-cylinder, two-row 160 h.p. Gnome was closely cowled and faired into the circular section, wooden monocoque fuselage. Single centre-section and interplane struts were used and both upper and lower wings had full-span ailerons which could be brought into play as landing flaps. The undercarriage was reduced to three struts and a leaf-spring axle, but uncontrollable swaying on the ground brought a reversion to the conventional vee-type structure. Another very advanced feature was the moulded celluloid cockpit canopy which was so distrusted by the pilots that it was soon discarded. With its original engine the S.E.4 No. 628 achieved a top speed of 135 m.p.h., making it the World’s fastest aircraft of its time. The 160 h.p. Gnome gave trouble with cooling, however, and was replaced by a 100 h.p. Monosoupape Gnome with an attendant drop in speed to 92 m.p.h.
   Although it was a brilliantly-conceived design, and was liked by its test pilots Norman Spratt and Major J. M. Salmond, the S.E.4’s landing speed of 52 m.p.h. was thought excessive for general use and, after damage in a landing accident, it faded from the scene. During its brief career, the S.E.4 had shown just what could be achieved at such an early stage in scout and fighter development and the machine remains a masterpiece of early aeroplane design.
   During 1915 designers were still faced with the two main alternatives of either the pusher or tractor layout for the armed scout. Steady evolution of the tractor type in general had endowed it with every advantage but one over the untidy pusher. The exception was still the installation and effective aiming of a forward-firing gun. In time a solution is found for every problem but, pending one for this particular obstacle, the Royal Aircraft Factory went ahead in 1915 with the design of another single-seat tractor scout.
   Although little connected with the S.E.4 - general overall layout and duty being about all that they had in common - the new machine was designated S.E.4a. H. P. Folland’s talents as a designer were responsible for the creation of the elegant and trim little newcomer, which exhibited simpler construction than that of its predecessor. The streamlined form of the S.E.4a’s fuselage was achieved by the addition of formers and stringers to the main rectangular-section, wire-braced framework of longerons and spacers. The 80 h.p. Gnome’s propeller was faired into the cowling ring with a large shallow spinner, inside which a fan cooled the engine with air drawn through the front orifice. Metal panels covered the nose as far back as the cockpit, the remainder of the airframe receiving the usual doped fabric covering. The staggered, equal-span wings were of single-bay cellule; the lower planes were joined to a centre-section, while the upper pair met at the centre-line to be joined to the fuselage by a pair of inverted V struts. The S.E.4a incorporated the idea, carried out on the S.E.4, of full-span ailerons which acted also as flaps. The machine’s fin and rudder profile was notable as that which stamped it and many succeeding fighters as Folland designs. The S.E.4a was an excellent example of the axiom that an aeroplane which looks right should fly well, a truth which was amply demonstrated by Frank Goodden with aerobatic displays at Farnborough.
   Overheating of the engine, even though the fan had been incorporated, brought about the discarding of the large spinner and the modification of the cowling to remedy the defective cooling. In all, four S.E.4as were produced by the Factory during 1915 and the 80 h.p. le Rhone was fitted as an alternative to the Gnome. To overcome the difficulty of firing straight ahead, a mounting for a Lewis gun was fitted above the upper wings at the apices of the centre-section struts so that the line of fire passed over the propeller, alternative armament being a rifle mounted at an angle on the fuselage side. Although it was a successful design and eminently suited to production, the S.E.4a constitutes yet another promising type which was unlucky enough to be passed over as a service machine. The only known military use made of it was that one was available at Joyce Green for Home Defence in the closing days of 1915.
Fifteen months or so after the Royal Aircraft Factory had produced the breathtaking BS I, they once again broke the mould with their extremely advanced SE 4 scout, which made its debut in June 1914. The machine is seen here in August 1914, shortly after being fitted with more conventional landing gear than the unsatisfactory original item. This one-off single seater, serial no 628, used a neatly cowled 160hp twin row Gnome rotary, giving it an astonishing top level speed of 135mph at sea level, along with an equally impressive 1,600 feet per minute initial rate of climb. Regrettably, the sole SE 4 was damaged beyond repair in a landing accident on 12 August 1914. Even more tragically, this mishap appears to have deterred any further development of the type.
The trim S.E.4a of 1915.
At the same time as the D.H.2 was being evolved at Hendon, to the South at Farnborough J. Kenworthy was at work in the precincts of the Royal Aircraft Factory on a contemporary single-seat pusher fighter - the F.E.8. The time taken from conception to realization of the D.H.2 was remarkably short as the dedicated Airco staff, under the energetic George Holt Thomas, applied their resources to producing the prototype as quickly as possible. The F.E.8 was not quite as lucky as, although design work had been initiated in May, 1915, the prototype first saw the light of day during the following October and ensuing troubles delayed its introduction into service. The F.E.8’s span was slightly greater than that of the D.H.2, while its weight using the same engine - the 100 h.p. Monosoupape Gnome - was a little less than that of the de Havilland machine; the speed at sea level was approximately the same for both, the F.E.8 reaching 94 m.p.h. compared with the D.H.2’s 93 m.p.h. The F.E.8, as a two-bay pusher biplane, possessed little of the pleasingly-proportioned appearance which the well-rounded, balanced lines of the D.H.2 presented to the eye. Instead, the Factory product was by comparison square-cut, angular and spindly. The prototype F.E.8’s four-blade propeller was embellished with a pointed spinner of generous size which could have had but a negligible effect upon performance and which was subsequently deleted on production examples. The F.E.8’s all-important armament was a single Lewis gun which, on the prototype, was installed at a low level in the nose of the nacelle. Except for the short exposed nose portion of the barrel, the gun was completely contained within the nacelle and was intended to be remotely controlled by the pilot seated above and behind it. Accessibility was poor, particularly so in flight and the gun was consequently elevated to a normal location on top of the coaming. Only a month after its appearance the first F.E.8 was wrecked in a crash in November, 1915, Service Trials in France being delegated to the next example which was completed in time to cross the Channel in December. Pilots who flew it liked the machine and their recommendations resulted in its immediate adoption for the R.F.C. Production, however, was unpleasantly slow in getting under way, six months passing before the first arrived to do battle over the Front. Alternative trial engine installations were the le Rhone and Clerget, both of 110 h.p., but any advantage in performance which they may have offered was of little benefit to a type which was out-dated by the time that it reached operational status.
F.E.8 prototype.
While the F.E.2b and F.E.2d were thus playing their part in the air war, another Royal Aircraft Factory design, the B.E.2c, was modified as a singleseat fighter in response to pressing demands from the Royal Flying Corps for such a type. Rather than set about designing a completely fresh machine, the Factory decided that the most expeditious way of meeting the case would be to modify the B.E.2c as dictated by the requirements.
   Airframe 1697 was selected for conversion into the prototype B.E.12, the designation allotted to the project. A new engine, the 150 h.p. R.A.F.4a, was installed in the nose and the front cockpit was deleted. Production B.E.12s embodied several detail modifications to provide increased fuel capacity and improved performance. Normal armament applied to the B.E.12 consisted of a single Vickers gun mounted to port on the fuselage and equipped with Vickers interrupter gear. Occasionally, additional fire-power was provided by a Lewis gun installed to starboard on a Strange mounting and alternative armament fitted consisted of a pair of fuselage Lewis guns on Strange mountings.
   The B.E.12 arrived in France to do battle in mid-Summer of 1916 but, in producing the conversion, the fundamental fact had been overlooked that inherent stability was a highly-developed feature of the B.E.2c but was not a quality which was in the least compatible with a fighter’s primary and essential requirement of manoeuvrability. The extra power and armament did nothing to meet this need and the B.E.12 was patently unable to rise to the requirements for which, in good faith, it had been designed. After but a few months’ use as a fighter, the B.E.12 was relegated to duties as a single-seat bomber.
   And yet, a further attempt was made to turn the B.E.12 into a successful fighter by producing a new version with single-bay wings. This was the B.E.12a which had the same 150 h.p. R.A.F.4a engine but was fitted with greatly extended tips to the upper wings. These tips terminated in ailerons given exaggerated horn balances which reached forward to the leading edge. The design proved unsatisfactory and was modified to use normal B.E.2e wings with strut-connected ailerons on each tip. At first this revised type was known as the B.E.12Ae but soon reverted in nomenclature to B.E.12a. All of this endeavour was in vain as the B.E.12a was as much a failure as the B.E.12 and served only in small numbers.
   An addition to the Home Defence fighter force during 1917 was a more powerful version of the B.E.12 with the 200 h.p. Hispano-Suiza engine and designated B.E.12b. A pair of Lewis guns on the upper centre-section armed the machine, thirty-six of which operated with Home Defence units.
Among the projected designs under way at the Royal Aircraft Factory when the War started was an ambitious layout by H. P. Folland and S. J. Waters for a large, twin-engine biplane armed with the Coventry Ordnance Works 1-5-pounder gun. Some time passed before the new machine, designated F.E.4 and intended for ground attack duties, was ready. The first of the two built was finished in 1916 and was powered by two 150 h.p. R.A.F.5 pusher engines which were employed to propel a machine with a span of 75 ft. 2 in.
   An odd aspect of the disposition of the crew members in the front cockpit was that the forward gunner was expected to operate the C.O.W. gun from his seat behind the pilot. The third man in the crew, another gunner, was sited in the fuselage aft of the wings. The machine’s large span brought about folding of the upper wingtips’ overhang which was hinged to drop downwards when necessary. Some alterations were apparent in the second F.E.4, on occasion known as the F.E.4a, which made its initial flight on 16th March, 1916. The engines had been changed to a pair of 250 h.p. Rolls-Royce Eagles and the rear cockpit deleted. An experimental gunner’s position was tried out in the centre-section of the upper wings, and an installation was made of a pair of Lewis guns which fired forward from each side of the fuselage gunner’s position behind the pilot.
   The F.E.4 represented another attempt to carry heavy armament into action by means of a large, weighty airframe, a concept which was not a happy one as two great essential ingredients in the formula for a fighter, those of manoeuvrability and speed, were lacking.
   Notwithstanding, two more designs, the F.E.5 and F.E.7 biplanes, were investigated as projects, both of them being developments of the F.E.4. The F.E.5 was to have been even larger, with a span of 103 ft. and would have had twin fuselages and three R.A.F.5 engines; the F.E.7 would have exploited a theme which was a favourite one with designers now and then, namely that of a central engine bay in the fuselage driving outrigged propellers. In the F.E.7’s case, the power plant was scheduled to be a pair of 250 h.p. Rolls-Royce Eagles with shafts and gears connection to the propellers. The F.E.7 was proposed as a two-seater, with a gunner operating a battery installation of multiple machine-guns.
December, 1916, was an auspicious month for it saw the completion of two of the most successful designs in the annals of British single-seat fighters - the Royal Aircraft Factory’s S.E.5 and the Sopwith Camel. Both machines were destined to play outstanding parts in the turbulent air fighting over the Western Front and their names were to form a glowing part of the legend of the first great War in the Air.
   The Farnborough S.E.5 was next in the line of Scouting Experimentals after the S.E.4a and its fin and rudder outline immediately indicated the hand of H. P. Folland again as the designer. Frank Goodden and J. Kenworthy contributed to the overall design and involved also were F. M. Green as design engineer, S. W. Hiscocks as his assistant, H. Grinsted as stressman, with W. S. Farren responsible for the aerodynamic and stability calculations. The S.E.5’s trim, well-balanced outline stamped it undeniably as a thoroughbred and the machine lived up fully to the promise it inspired.
   The machine’s wooden airframe was a normal structure with fabric covering and was centred around the 150 h.p. Hispano-Suiza engine with a flat frontal radiator. The single-bay wings were set with pronounced stagger and carried four ailerons, and the tailplane embodied the refinement of variable incidence controllable during flight.
   The prototype A4561 took off for the first time during December, 1916, and was soon modified with revised exhausts and increased windscreen area to the rear. The prototype’s life, however, was short as the wings failed late in January, 1917, during testing by Frank Goodden who was killed in the resulting crash. Modifications were made and the S.E.5 went on to make its great name in the hands of squadron pilots, the first unit to receive the type being No. 56 Squadron, R.F.C., during March, 1917. The armament of the S.E.5 comprised a Vickers gun mounted to port on the front decking and a Lewis gun on a Foster mounting which carried it on top of the upper centresection. The first production S.E.5s were delivered complete with a large windscreen over the front and sides of the cockpit but this was quickly replaced by a small screen of simple, flat form in the interest of visibility from the cockpit.
   By mid-1917 a revised version of the S.E.5, the S.E.5a, had started to reach the squadrons, No. 56 being the first to receive it. The new machine was powered by the geared 200 h.p. Hispano-Suiza and embodied minor alterations in the fore-fuselage. The higher-powered engine suffered from lack of reliability but the S.E.5a soon vindicated itself and established a first-class reputation amongst its pilots. The machine went into service with alternative engines which included the Hispano-Suiza of 220 h.p. and 240 h.p., the 200 h.p. Wolseley Viper W.4A and the 200 h.p. Wolseley Adder W.4B.
   As the War progressed through its final year two further Scouting Experimental designs were indulged in by the Royal Aircraft Factory designers. One, the S.E.5b, was built as a modification of an S.E.5 - A8947 - for comparative tests with the standard S.E.5a. The 200 h.p. Hispano-Suiza was streamlined into the nose, assisted by a large spinner, and a semi-retractable radiator of reduced area was installed underneath the engine to effect a considerable saving in drag. New unequal-span wings were fitted and the machine was tested also with normal S.E.5a wings, in which guise the designation S.E.5c was at times applied to it. The S.E.5b was given the standard S.E.5 armament of one Vickers gun and one Lewis gun.
   The other S.E. design, the S.E.6, remained an incomplete project but would have been a single-seat biplane to the same requirement as the Martinsyde F.3 with the useful power of the 275 h.p. Rolls-Royce Falcon III.
   After barely six years, the busy period of aeroplane design activity at the Royal Aircraft Factory came to an end but the organization could look back with satisfaction on time spent in developing a useful range of machines. Particularly noteworthy were its Scouting Experimentals, each of which had been in the forefront of advanced design and construction techniques, culminating in the outstandingly successful S.E.5 and S.E.5a.
The prototype S.E.5 A4561, forerunner of one of the finest types of fighter of the 1914-18 War.
During 1916, the Royal Aircraft Factory undertook the design of another pusher fighter reconnaissance machine, the F.E.9 biplane. The 200 h.p. Hispano-Suiza provided the power and the gunner was given an excellent field of fire. By 1917, when the three F.E.9’s built were completed, the comparatively untidy pusher layout was hardly expected to compete with tractor types and the F.E.9 was consequently used in various experiments.
Contemporary with the ill-fated F.B.25 and similar in layout and purpose was the N.E.1, six of which were built by the Royal Aircraft Factory. Intended for night interception, the N.E.1 carried a searchlight in the nose of its crudely-shaped box-like nacelle, which was suspended between three-bay wings of fairly high aspect ratio. The 200 h.p. Hispano-Suiza provided the power to enable the machine to take aloft its main offensive armament of a Coventry Ordnance Works quick-firer or a Vickers rocket gun. In addition, a forwards-firing Lewis gun was mounted on the starboard side of the nacelle. Reports on the N.E.1’s handling and performance were not favourable towards its use as a night fighter so that it remained but an experimental design.
Although by 1918 the pusher formula with the propeller revolving between tailbooms had been more or less abandoned as a proposition for projected fighters, the Royal Aircraft Factory proceeded to construct three examples of the A.E.3 Farnborough Ram, a pusher biplane carrying two and intended for use as a trench-strafer. The A.E.3’s antecedent was the N.E.1 of the previous year but, as protection for its crew, armour plating 1/4 in. thick clad the angular nacelle which housed a pair of Lewis guns, pivoted for firing vertically into enemy troops, and carried also another Lewis gun for firing to the rear. The two versions of the A.E.3 were the 200 h.p. Sunbeam Arab Ram Mk.I and the 230 h.p. Bentley B.R.2 Ram Mk.II. A Mk.III version of the Ram was considered as a project and would have used the lower-powered 150 h.p. Bentley B.R.I.
Among the firms engaged in sub-contract work which were tempted to strike out and build original designs of their own was that of Robey of Lincoln. Previously busy producing the Sopwith Gunbus for the Admiralty, in 1915 J. A. Peters evolved two contrasting single-seat biplane scouts in the company’s drawing-offices; one was a pusher, powered by either the 80 h.p. Gnome or the 90 h.p. Salmson M.7, and the other was a tractor for which the engine scheduled is thought to have been the 80 h.p. Clerget. The Robey pusher was of single-bay, unequal-span wing form and the pilot was seated high up in a nacelle upon which rested the upper wings. The general appearance was commendably clean and, with the Salmson engine, estimated top speed was 93 m.p.h.
   The Robey tractor, which followed the general trend of small single-seat tractor scouts of its time, possessed a very simple airframe.
   The two Robey single-seaters are among the least-known of the early British scouts and little has survived concerning either machine. The pusher is reported to have come to grief during its initial flight and it is not known if the tractor flew at all.
Among the firms who, during 1917, constructed prototypes specifically to carry the Admiralty-sponsored Davis recoilless gun, was that of Robey and Co. whose designer, J. A. Peters, evolved a large three-seat, three-bay tractor biplane to carry two of the large shell-firing weapons on the power of a 250 h.p. Rolls-Royce engine. Disposition of all three members of the crew was somewhat remarkable; the two gunners were located each in a nacelle faired into the upper wings on each side of the fuselage, while the pilot was situated no less comfortably in a cockpit towards the rear of the fuselage just ahead of the fin. As with the other prototypes designed to accommodate the Davis gun, the Robey-Peters Three-seater came to naught, in its own case being abandoned after crashing during its initial flight.
Clifford Tinson, late of Bristol and the Admiralty’s Air Department, was engaged by Sage and Company at the beginning of 1916 as Chief Designer. His first design for the firm was a two-seat biplane fighter with a wing span of only 22 ft. 2-5 in. and arranged so that the gunner received an unrestricted field of fire by standing to fire his Lewis gun through 360 above the upper wings. The engine was the 100 h.p. Monosoupape Gnome in a neat cowling, and a glazed cabin enclosed the crew and supported the upper planes. After flying for the first time on 10th August, 1916, the Sage Type 2 crashed on the 20th of the following month at Cranwell. The design was then abandoned as the style of armament installation had been rendered unnecessary by the advent of the synchronizer gear.
The Sage Type 2 with gunner’s position above upper wings.
By the same year, Short Brothers had become a firmly-established company with a number of extremely successful practical designs to their credit and had already begun to specialize in floatplanes, a type of machine in which they rapidly excelled and for which they were justifiably widely known. Among their products for 1913 was the S.81 Gun-carrier, designed for them by A. Camden Pratt specifically to carry out tests of armament. The machine was destined to be the final pusher Short floatplane and was a three-bay biplane, the wings of which folded. No.126 was a fairly large machine and was supported on the water by twin main and tail floats, augmented by one under each lower wingtip. A 160 h.p. Gnome provided the power at the rear of a nacelle which had to be particularly strong to stand up against the tremendous recoil of the quick-firing Vickers 1-5-pounder gun, for the thorough testing of which the S.81 had been ordered from Short Brothers.
   These trials had been instituted by the Naval Wing of the R.F.C. on 29th July, 1913, when Lt. R. H. Clark-Hall, a naval gunnery officer, had been given the job of supervising the assessment of suitable armament for naval aeroplanes. First intentions were that the Vickers 1-5-pounder received by the Navy was to be installed in the Astra Torres airship and then in a Sopwith Gunbus but the big gun finally found a home in the S.81, only one of which was built. The Gun-carrier carried out its allotted task for some two years, being used in early 1915 as a vehicle for the testing of the recoilless 6-pounder Davis gun.
While other firms were engaged in producing the smaller type of fighting scout, Short Brothers constructed a relatively large two-seat, three-bay biplane seaplane, powered by the 310 h.p. Sunbeam Cossack, and known as the 310 Seaplane Type B, or North Sea Scout. The machine was designed mainly to carry the 5-pounder Davis recoilless gun and was equipped also with a Lewis gun, both weapons being installed in the rear cockpit, but the cancellation of the Davis gun’s development brought about the discontinuation of the Short North Sea Scout.
Short Type B North Sea Scout.
March, 1917, saw the appearance of another Short scout seaplane, the S.364 two-seat biplane powered with the 200 h.p. Sunbeam Afridi. Two-bay wings of equal span were used and, compared with the ungainly angularity of other Short products of the period, the S.364 presented a far tidier picture. A single Lewis gun was provided for the rear cockpit’s Scarff ring but the S.364 was not developed beyond the prototype stage.
March, 1917, saw the appearance of another Short scout seaplane, the S.364 two-seat biplane powered with the 200 h.p. Sunbeam Afridi. Two-bay wings of equal span were used and, compared with the ungainly angularity of other Short products of the period, the S.364 presented a far tidier picture. A single Lewis gun was provided for the rear cockpit’s Scarff ring but the S.364 was not developed beyond the prototype stage.
The S.1’s more successful counterpart from the Sopwith stable, the nimble little Tabloid, had meanwhile been energetically developed into a useful scout at Kingston, following its dramatic victory in the Schneider contest at Monaco. The landplane Tabloid, fitted with the 80 h.p. Gnome, was in production for the R.F.C. and R.N.A.S. as a single-seater. A triangular fin was added at the tail and the front struts of the undercarriage were raked forward more sharply than on the original machine. Some of the production Tabloids were given an extra pair of struts in the undercarriage for additional strength.
   On the outbreak of war, four R.F.C. Tabloids were taken to France and were used, unarmed, for scouting by Lts. Gordon Bell and Norman Spratt during the early operations on the Western Front. To render his Tabloid more warlike Spratt carried a supply of flechettes, a form of sharp steel dart, which could be thrown out of the cockpit onto a target.
   When the R.N. A.S. entered the conflict, one Tabloid was on strength but four finally went to Cdr. C. R. Samson’s R.N.A.S. Squadron. Two of them, Nos. 167 and 168, earned immortal fame for the epic raid which was carried out by their pilots - Sqn.Cdr. Spenser D. A. Grey, who bombed Cologne railway station, and Flt.Lt. R. L. G. Marix, who destroyed the Zeppelin Z.IX in its shed at Dusseldorf.
   The Tabloid went into action devoid of any armament but Samson’s machines were fitted in February, 1915, with a Lewis gun mounting on the upper centre-section, an installation which was the brainchild of Wt.Off. J. G. Brownridge and Lt. T. Warner. Another Tabloid belonging to the R.N.A.S. was equipped with a Lewis gun installed on the starboard side of the fuselage, beneath the centre-section struts and enabled to fire through the propeller arc by the very rudimentary arrangement of steel deflector wedges, which were strapped around the specially shaped blades in the line of fire. Any bullet which might otherwise have hit the propeller during the uninterrupted firing of the gun was, therefore, made to ricochet off.
   In addition to the few Tabloids built prior to 4th August, 1914, another thirty-six were constructed from 1st October until 30th June, 1915, with ailerons taking the place of wing warping on later examples. This comparatively small production run meant that the type was unable to make much of a name for itself, but the Tabloid stands at the head of the subsequent lengthy line of scouts and fighters which were to emanate from Kingston.
Sopwith Tabloid prototype at Brooklands.
Sopwith Tabloid prototype
Among the aeroplanes pressed into service for anti-Zeppelin patrols were Sopwith Two-Seater Scouts, of which twenty-four had been produced and absorbed by the R.N.A.S. An unexpected tendency to slip into a spin was responsible for the nickname Spinning Jenny being earned by the type, which proved virtually useless as an interceptor of Zeppelins. Tugged aloft by its 80 h.p. Gnome the ungainly Sopwith was hard put to gain a meagre 3,000 ft. in height and wallowed far below the quarry which it was sent up to destroy from Coastal Air Stations.
   The Spinning Jenny was basically a landplane version of the Sopwith Type 807 seaplane of 1914. Two-bay wings of equal span were fitted to a fuselage which was more or less identical with that of the Type 807, the tail unit also following the same pattern. A rather mixed range of armament was fitted to the anti-Zeppelin Scouts and consisted of combinations of the German Mauser rifle loaded with incendiary ammunition in the hope of setting fire to the marauders, the normal service rifle with Hales grenades, a shot-gun containing chain-shot, and the Very pistol.
The two-seat Sopwith Scout, the Spinning Jenny.
Although the single-seat tractor scout was gradually beginning to come into its own at the time of the commencement of the War, the pusher layout - with its undoubted facilities for the installation and use of machine-guns - was being strongly pursued in the two-seat form.
   In August, 1914, the Sopwith company were busy completing for the Greek Naval Air Service six landplane versions of their 1913 Greek Seaplane. The additional order had been placed in March, 1914, following the Greek Government’s approval of the first example on floats. The new machines were to be armed with a single Lewis machine-gun in the front of the nacelle and the revised type became known as the Gunbus. The Greeks never received their expected Gunbuses as the six aircraft found themselves taken over by the Admiralty. The original Greek Seaplane had used a 100 h.p. Anzani engine but this was supplanted in the production batch of Gunbuses by the 100 h.p. Monosoupape Gnome and, in order to bestow as good a field of fire as possible, the nacelle’s fore part was revised in shape.
   After the batch of six were delivered, the Gunbus was revised again and received increased power by the installation of the 150 h.p. Sunbeam. The nacelle and undercarriage had to be strengthened to absorb the extra power and improved protection for the crew resulted from increasing the depth of the decking of the nacelle. In the original Gnome-powered design, the lower wings were mounted direct onto the sides of the nacelle but in the Sunbeam version they passed below it, to be attached by short struts. At the same time, a new horn-balanced rudder of increased area made its appearance and straight-edged horizontal tail surfaces were incorporated. Besides being built by Sopwith, the Gunbus was sub-contracted by Robey and Co. at Lincoln but, even though such a useful gun-carrier was available when the emergency arose, the production run of twenty-three complete machines was very small and no particularly noteworthy successes attended whatever operational use was made of the machines. The Gunbus, with its span of 50 ft., was of fair size and managed to reach 80 m.p.h. with the Sunbeam as power. Its severely restricted employment as an operational type was offset by the R.N.A.S. putting it to good use as a trainer at Hendon.
Sopwith Gunbus
The value of a single-seat scout seaplane with good all-round performance was appreciated by the Admiralty, particularly in view of the widespread commitments of the R.N.A.S. along the coasts of the British Isles, and the Tabloid seaplane was ordered into production in November, 1914, being given in recognition of its sparkling achievement earlier in the year the well-merited appellation Sopwith Schneider. The 100 h.p. Monosoupape Gnome was standardized as its power plant and the Schneider was little altered from Howard Pixton’s contest mount apart from the appearance of an extra pair of struts in the undercarriage. The bull-nose cowling over the upper portion of the rotary afforded protection from oil and gases whipped back in the face of the pilot and, at the same time, gave a fair view over the blunt nose.
   Original production Schneiders utilized the triangular fin shape but of slightly greater area than used on the Tabloids, together with wing warping; the fin was subsequently increased in area and given a curved leading edge and, conforming with advancing aerodynamic practice, ailerons on all four wings supplanted the strain-inducing warping. This final rejection of the warping system of lateral control was long overdue and was made not a moment too soon. The twisting of the wings’ structure imposed totally unnecessary strains, particularly where biplane cellules were involved, which were eliminated when the simple and effective aileron became accepted fully.
   The Spinning Jenny was obviously not going to be of any use in destroying Zeppelins and another Sopwith type, the single-seat Schneider, was turned to in the hope of succeeding where its two-seat compatriot had failed. As the Schneiders came off the accelerated production lines during the first months of 1915, they were directed by the R.N.A.S. to its coastal seaplane stations and also passed to some ships as part of their equipment. The Schneider’s brisk performance, allied to its incendiary bullet-firing Lewis gun which was mounted at an angle through an aperture in the upper centre-section, was expected to provide a satisfactory means of bringing the raiders down. Actual attempts to use the Schneiders from cruisers and seaplane-carriers in the North Sea when Zeppelins were sighted overhead in May, June and July of 1915 were failures from various causes, one of which was an unfortunate propensity for breaking their float structures on being swung into the water for taking-off. To overcome this obstacle and get the intercepting Schneiders cleanly into the air with as little loss of time as possible, the idea came from Admiral Sir John Jellicoe, in a letter to the Admiralty at the end of July, 1915, that the machines should be released from the 120 ft. flying-off deck of the aircraft-carrier Campania. By placing a jettisonable two-wheeled dolly beneath the floats, the seaplanes could then get smoothly and quickly away. 6th August, 1915, saw the first successful take-off by this method from Campania when Flt.Lt. W. L. Welsh was launched in a Schneider after a run of 113 ft. while the ship steamed at 17 kt. into wind. The little Sopwith had deservedly made a niche for itself in the R.N.A.S. and increasing demands meant that extra equipment was finding its way aboard to the gradual detriment of the machine’s performance. An increase in power was obviously essential and the 110 h.p. Clerget was selected as the answer. The change of engine brought with it an alteration in the cowling, which lost its old bull-nose character and assumed instead a horse-shoe aspect, open-fronted and terminating at the apices of the front landing-gear struts. With the new version’s appearance in September, 1915, there came the change of name to Sopwith Baby.
   The Fairey Company was more successful with its adaptation of the Sopwith Baby seaplane which it redesigned as the Hamble Baby to incorporate the Fairey Patent Camber Gear which consisted of wing trailing-edge flaps, used to produce increased lift and doubling as ailerons. Out of a total of one hundred and eighty Hamble Babies built, one hundred and thirty were by Parnall and Sons and, of these, seventy-four were on land undercarriages and known as Hamble Baby Converts.
N1123, a Blackburn-built Sopwith Baby.
Sopwith Schneider
Sopwith Baby
In the course of 1915, the Sopwith Aviation Company’s design office had prepared drawings for a two-seat biplane which was destined for a very successful career and for particular distinction as the first British tractor aircraft produced with a properly synchronized gun for the pilot to fire forward between the spinning propeller blades. With the construction of the prototype during the last few weeks of 1915, the Sopwith firm placed at the disposal of the Services a machine which was a great step forward in equipment.
   Apart from its advanced armament installation there was nothing radical about the new Sopwith, which officially to the R.N.A.S. was the Sopwith Type 9700 and to the R.F.C. the Sopwith Two-Seater. However, neither of these designations was that under which the machine passed into its distinguished niche in the annals of British military aircraft. Universally, it became the 1 1/2-Strutter, an appellation which is generally conceded to have evolved through the unusual arrangement of short and long pairs of centre-section struts. Powered by the 110 h.p. Clerget, the 1 1/2-Strutter represented a logical development, embodying the valuable experience in the techniques of design and construction amassed by the Company during the past few years.
   The pilot’s single Vickers gun was installed centrally on the front decking and, in the case of those used by the R.F.C., was synchronized with Vickers-designed gear, while those ordered for the R.N.A.S. used the Scarff-Dibovsky gear. As well as providing for the first time a fully effective weapon for the use of the pilot, the 1 1/2-Strutter carried a Lewis gun in its rear cockpit. The simple and rather restrictive Scarff-designed socket-and-pillar fitting for the rear gun, employed for the first 1 1/2-Strutters, was replaced on later versions for a while by the Nieuport ring type of mounting which bestowed greater mobility on the gun. The Nieuport mounting was not ideal, owing to its awkward arrangement and size, and Wt.Off. Scarff was not long in devising a great improvement with his No. 2 ring mounting. The Sopwith-Kauper and Ross gears were also installed for the front gun in later examples of the 1 1/2-Strutter.
   In addition to its armament innovations, the type incorporated a tailplane with variable incidence, which was altered during flight by a wheel control in the pilot’s cockpit, and hinged flap airbrakes in the lower wing roots.
   The Admiralty was earliest to show interest in the 1 1/2-Strutter as equipment for the R.N.A.S. and started the ball rolling with an initial order for one hundred and fifty, the first of which became available early in 1916. The R.N.A.S. commenced to use their machines with success as bombers and intended to develop such attacks on the Germans. However, the R.F.C. was so short of suitable aeroplanes prior to the opening of the Battle of the Somme, that, following a request from the War Office, the Admiralty agreed to transfer a considerable number of its 1 1/2-Strutters. The R.F.C. had also, on its own account, ordered 1 1/2-Strutters for its re-equipment, the initial machines of the procurement going to No. 70 Squadron. The type soon proved its worth over the battle front and was a welcome and reliable addition to Allied air strength.
   In retrospect, the Sopwith 1 1/2-Strutter is seen as the pioneer of the classic two-seat, tractor fighter layout, a concept which was to be exploited and developed to a very high degree for the ensuing two decades.
Sopwith 1 1/2-Strutter.
The other fighter which was to earn undying fame for itself, the paradoxically-named Sopwith F.1 Camel, also emerged during December, 1916. The Camel paralleled the S.E.5 as a single-bay biplane of purposeful aspect but utilized the rotary air-cooled 110 h.p. Clerget engine in the prototype. Production F.1s were built with the 110 h.p. le Rhone and the 130 h.p. Clerget engines as alternative power plants.
   Conventional in construction, the Camel was nevertheless an inspired design with outstanding manoeuvrability as a primary feature ensured by concentrating the engine, guns and pilot in the short forepart of the fuselage around the C.G. The twin Vickers guns were under the immediate control of the pilot in the coaming in front of the cockpit. The swift response of the Camel and its pronounced sensitivity made it an ideal fighter but pilots new to it had to be very wary indeed of the considerable torque effect exercised by the engine. Once its habits and qualities were understood and mastered, the Camel was without peer in its time and ran up a score of 1,294 enemy aircraft destroyed, to better that of any rival machine during the conflict.
   The success of the Camel and the S.E.5 led naturally to further development of both types during 1917. Various alternative engines were installed in the Camel and a special naval version went into production as the 2F.1. Successful take-offs were made from lighters towed by destroyers, trials were carried out in launching from H.M. Airship R.23 and a number of different armament installations were tested on Camels. Night-fighting Camels were produced by moving the cockpit rearwards to facilitate access to the pair of Lewis guns on their Foster mounting above the upper centre-section and a prototype trench fighter, the T.F.1, was built with a pair of downwards-firing Lewis guns in the fuselage and a third Lewis fitted above the upper centre-section.
   2F.1 Camels operated from warships’ platforms rendered useful service, following in the footsteps of the Pups which had pioneered such operations with the Fleet, including carrier landings.
Classic dog-fighter of the 1914-18 War, the Sopwith F.1. Camel.
C42 unit and location unknown
The Sopwith tender to the specification was a three-seat triplane also, designated L.R.T.Tr. but less frighteningly unusual than the F.K.6. The most significant feature of the Sopwith design was the gunner’s nacelle - of excellent aerodynamic form - mounted on the centre-section of the top wings. From this commanding position the field of fire was first-class and a second Lewis-gunner occupied the rear cockpit to guard the machine from attack in that quarter. The 250 h.p. Rolls-Royce Mk.l was installed in the L.R.T.Tr. and the wings, besides incorporating ailerons on each tip, embodied airbrakes in the lowest set of planes.
The experimental Sopwith L.R.T.Tr. three-seat triplane escort fighter.
Both projects came to naught but a bright star was rising in the rapidly-developing single-seat firmament with the appearance early in 1916 of the Sopwith Pup. Compact and well-balanced in design, the machine did not betray by its performance and handling qualities the confidence which its appearance inspired. Pilots were unanimous in their unqualified praise for the new product from Kingston. The construction of the Pup, known originally to the R.F.C. as the Sopwith Scout and to the R.N.A.S. as the Sopwith Type 9901, was of standard wood and fabric style and carried on the successful type of split axle undercarriage pioneered by the Sopwith Company. The 80 h.p. le Rhone was chosen to power the Pup, which carried a single Vickers gun fixed on the decking in front of the pilot and synchronized with the Sopwith-Kauper gear. The first six prototype Pups went to the R.N.A.S. and production examples followed in the Autumn of 1916. Ship-board versions featured an alteration in armament in which a Lewis gun was carried on a steel-tubing mounting so that it fired upwards at an angle through the centre section cut-out.
   The Pup was a success from its first appearance in service and continued to display its superiority over adversaries throughout 1917, contributing valuable assistance in the day-to-day operations in the air war.
Despite its many advanced features, the Night Hawk remained a single prototype but, during the same period, the Sopwith Company was engaged on a comparably unusual design which was destined for fame and success. Supermarine’s quadruplane was unable to make the grade but the Sopwith Triplane’s attributes were such that it soon established itself favourably in service.
   Although it bore itself on three sharply-staggered, narrow-chord wings, the Triplane prototype N.500 when it materialized at the end of May, 1916, was an eminently neat, practical design. Single interplane and centre-section struts braced the single-bay layout which was mated to a fuselage, tail unit and undercarriage close in appearance to those of the Pup. The power of the 110 h.p. Clerget engine, coupled with the small span of 26 ft. 6 in., endowed the Triplane with excellent manoeuvrability, climb and general all-round performance. Standard armament consisted of a single synchronized Vickers gun on the front decking but six were produced carrying a pair of Vickers in the same location.
   Both the Admiralty and the War Office ordered the Triplane in substantial numbers but, as a result of inter-Service exchanges of aircraft in an endeavour to redress the position on the Western Front, the Triplane was operated only by the R.N.A.S. squadrons, in whose capable and enthusiastic hands it soon struck fear into the hearts of the German crews once deliveries started at the end of 1916.
   The substitution of the 130 h.p. Clerget brought a corresponding benefit to the performance and the Triplane soared to its greatest heights of success with its exploits in the all-Canadian “B” Flight of No. 10 (Naval) Squadron under Flt. Sub-Lt. Raymond Collishaw. The Sopwith Triplane vindicated gloriously the faith which its designers had placed in the radical concept which it represented for a service aeroplane.
A successful British triplane, the Sopwith Triplane.
Sopwith Triplane
While the Clerget-powered triplane was establishing its reputation, two examples of a Hispano-Suiza-engined triplane single-seat fighter appeared from Sopwith - N509 with the direct-drive 150 h.p. and N510 with the geared 200 h.p. Both machines were somewhat larger than the Clerget-engined triplane but each was armed with a single Vickers gun in front of the pilot. Supplies of the engine were earmarked for the promising S.E.5 and the Hispano-Suiza triplane was not developed into a production type.
Sopwith Camel 2.F.1
While engaged in their production of scouts, the Sopwith Company built a very small single-seat biplane of 16 ft. 3 in. span and powered by a 50 h.p. Gnome for the use of H. G. Hawker, their test pilot. Trials were later made with the Bee, as it was named, after a single Vickers gun had been fitted to assess its use as a lightweight fighter but the design was not adopted.
The Sopwith designers did not rest on their laurels after turning out the Camel and followed it in May, 1917, with their 5F.1 Dolphin. The new fighter bore little, if any, resemblance to its illustrious predecessor and was notable in incorporating back-stagger in its two-bay, equal-span wings. The biplane’s gap was comparatively small, so that the pilot’s head projected through the upper centre-section.
   A deep nose radiator at first served the 200 h.p. Hispano-Suiza engine in the prototype Dolphin but was afterwards replaced by side radiators mounted one on each side of the cockpit. The prototype’s original fin and rudder, which followed the outline of the Camel’s, were changed for new surfaces complete with horn balance incorporated in the rudder. Further alterations to the vertical tail surfaces and to the fuselage around the cockpit area to improve the view took place before the Dolphin was considered ready to be issued to the squadrons. The Dolphin’s firepower was increased by the addition of a pair of Lewis guns, mounted in the centre-section on each side of the pilot, to fire forwards and upwards at around 45°. These extra Lewis guns did not prove particularly popular in use as they tended to swing during flight and to hit the pilot. Consequently, they were often discarded by the units using the machine but No. 87 Squadron, R.F.C., took to mounting the Lewis guns on the lower wings to fire outside the propeller disc. In each case, however, the main armament of two Vickers guns in the decking ahead of the pilot was retained. The Dolphin proved to be a sturdy and popular machine in service, one of the few adverse criticisms of it being the risk of injury to the pilot in a nose-over on landing. To guard against this the night-flying version was equipped with metal hoops above the inner pairs of interplane struts. The normal production Dolphin used the geared version of the 200 h.p. Hispano- Suiza but, as an alternative, the direct-drive 200 h.p. Hispano-Suiza was employed in the Dolphin Mk.III and the Dolphin Mk.II had the advantage of 300 h.p. delivered by the more powerful version of the Hispano-Suiza engine.
Sopwith Dolphin in its early form.
The feature of a deep fuselage filling the gap between the wings was adopted in a two-seat Sopwith fighter of 1918 - the 3F.2 Hippo - which incorporated back-stagger in its two-bay wing layout.
   Remarkable in the Hippo was that the cardinal rule in multi-seat fighter design - that of close proximity of the crew members to each other in the interest of maximum co-operation for operational duty and survival - was disregarded by locating the pilot in front of the wings and the observer’s cockpit in a cut-out at the trailing edge. Notwithstanding this disadvantage, both enjoyed good positions for operating their guns - the pilot with his pair of Vickers and the observer with his single or double Lewis guns. The 200 h.p. Clerget 11B rotary powered both the first Hippo and the second modified version, X11, in their trials early in the year but the type progressed no further than the pair of prototypes.
The first prototype Sopwith 3F.2 Hippo.
The prolific Sopwith design office’s output was increased by yet another machine which appeared in 1918 - the 2FR.2 Bulldog two-seat biplane. Intended for fighter reconnaissance, low-set on its landing-gear and heavy-jowled, the weightily-armed Bulldog was aptly named. The first prototype had single-bay wings and the 200 h.p. Clerget 11 E.B. rotary for power. Twin Vickers guns were provided in front of the pilot, while the aft cockpit was fitted with two Lewis guns, one firing forwards and the other to the rear.
   A second prototype was built with two-bay wings of larger size and initially had horn-balanced ailerons which were later replaced by revised wings with plain ailerons.
   Following the Bulldog Mk.I with its Clerget engine came another version, the Mk.II with the ill-starred 360 h.p. A.B.C. Dragonfly Ia radial for its power plant, but neither type of Bulldog was developed further.
The first prototype Sopwith 2 FR.2 Bulldog Mk.I with single-bay wings and Clerget engine installation.
The Sopwith Company, which had played such a prominent and successful part in the development of British fighters, finished early in 1919 their Dragon, a well-proportioned two-bay biplane single-seater developed from the experimental prototype Snipe B9967 which had been fitted with the 320 h.p. A.B.C. Dragonfly 1 engine. The Dragon received the benefit of the extra 40 h.p. delivered by the 360 h.p. Dragonfly 1A and was in reality Snipe E7990, altered accordingly. Two Vickers guns constituted the armament and the Dragon recorded the excellent top speed of 150 m.p.h. The first flight took place during January, 1919, and production proceeded into the middle of the year but not for adoption by the R.A.F.
Production Sopwith Dragon with horn-balanced ailerons.
The busy Sopwith factory proceeded to produce in the Spring of 1918 another single-seat two-bay biplane fighter - the T.F.2 Salamander - with the emphasis on trench strafing. In appearance closely resembling the Snipe, the whole fore-section of the fuselage was protected by armour plating. The Salamander’s engine was the 230 h.p. Bentley B.R.2, standard armament being a pair of nose-mounted Vickers guns. Experimental installations were tested consisting of batteries of multiple machine-guns, even to the extent of equipping one Salamander with eight guns concentrated to fire downwards through the bottom of the fuselage. The Salamander went into production but was too late to become operational before the Armistice and its very nature nullified use in the R.A.F. after the War.
In October, 1918, there emerged at Kingston an unusual venture for Sopwith - a single-seat, parasol monoplane fighter named the Swallow or Sopwith Monoplane No. 2. The machine was derived from the Scooter or Monoplane No. 1, which had appeared earlier in the middle of the year. The Swallow, B9276, used a Camel fuselage, a 110 h.p. le Rhone engine and carried a pair of fixed Vickers guns on the fore-decking. The machine was a very neat and attractive design but received no development beyond the single prototype.
During the final months of the 1914-18 War a number of new single-seat fighters were completed or were in the final stages to meet the requirements of the R.A.F. Type 1 Specification issued in 1918. Several prominent firms tendered to it and, among them, Sopwith produced three interesting prototypes.
   May, 1918, saw the appearance of the Sopwith 8F.1 Snail Mk.I, of particular note for its finely-conceived wooden monocoque fuselage. The Mk.I was completed after its sister Snail with a conventional fuselage structure covered with fabric, which had been rolled out during the previous month. Both machines used the temperamental 170 h.p. A.B.C. Wasp 1 as power but the Snail Mk.II differed from the Mk.I in having its wings set with a small amount of negative stagger as opposed to the other machine’s positive stagger.
A surprise Sopwith design was a new triplane, the single-seat Snark, with a monocoque fuselage mounting the 360 h.p. A.B.C. Dragonfly la engine following earlier installation of the 320 h.p. Dragonfly 1. Although its fuselage lines were clean, as usual with a monocoque structure, the appearance of the rest of the airframe fell far short of that of the earlier Sopwith Triplane. The Snark was designed as a high-altitude fighter and was given very heavy armament in the form of two fuselage-mounted Vickers guns and four Lewis guns fitted beneath the lowest wings. Three prototypes were built and displayed excellent performance and handling characteristics but, apart from the troubles of the Dragonfly, the day of the triplane fighter was past.
Development of new, improved fighter designs continued at even greater speed and 1918 brought forth a number of machines of advanced design and increased performance. Of the aircraft actually built or merely considered as projects during this period there was not one which could be classed as an impractical freak. Indeed, all of them demonstrated plainly a sensible, rational approach to the design of single- and two-seat fighters, exemplified by an overwhelming predominance of the single-engine tractor biplane of refined form. Designers had obviously appreciated that therein lay the formula for success in the art of fighter design for the present and the immediate future. Although the final year of the 1914-18 War was notable for such an inspiring selection of prototype fighters only one, the Sopwith Snipe, was to be adopted for service in the R.A.F. in quantity. Even so, relatively few Snipes had been delivered to operational units in France by the end of the War and the main burden of aerial fighting continued to be borne until the Armistice by other fighters already in service.
   The Sopwith 7F.1 Snipe grew out of a requirement for a new single-seat fighter to take the fullest advantage of the 230 h.p. developed by the Bentley B.R.2 rotary engine. The prototype flew first on the power of the 150 h.p. Bentley B.R.1 engine until a B.R.2 was delivered for it, the machine’s airframe using single-bay wings fitted to a flat-sided fuselage. A second prototype was constructed with curved fairings added to the sides of the fuselage, redesigned fin and rudder and other modifications. Conclusions formed following its tests in December, 1917, resulted in the appearance in January, 1918, of a third prototype, this time with two-bay wings of extended span. The Snipe’s excellent climb and general manoeuvrability and its lack of the trickiness which had characterized the Camel brought general approval of its selection as the R.A.F.’s new single-seat fighter. Further minor alterations were made in the airframe to improve the machine’s all-round qualities and its armament was standardized as two Vickers guns in the front decking. A long-range variant of the Snipe was designated 7F.1a and one was used to flight-test the 320 h.p. A.B.C. Dragonfly radial engine, with which it reached a speed of 156 m.p.h. The Sopwith Snipe is notable as being considered the best all-round single-seat fighter in operation by the Allies at the time of the Armistice and was to remain in R.A.F. service for some eight years.
B9966, fifth prototype of the Sopwith 7F.1 Snipe.
Sopwith Snipe
One more single-seat fighter, the Snapper, remained to emerge under the name of Sopwith from the Kingston factory. It was completed during the Spring of 1919 under the R.A.F. Type 1 requirement with a normal wooden box-girder fuselage; the original intention was to provide it with one of mono- coque type. In common with several latecomers on the British fighter scene at the end of the War, the Snapper used the 360 h.p. Dragonfly 1A radial engine from which so much had been expected and which endowed the single-bay biplane with a top speed of 140 m.p.h. The machine’s armament was the typical one of two Vickers guns and the Snapper terminated the line of Sopwith scouts and fighters which had been sparked off some five years previously with the Tabloid.
The first prototype Sopwith Snapper.
In the course of 1918, three single-seat fighters were planned by separate companies, each machine being within the Admiralty’s N.1B requirement. One of them, the Supermarine N.1B Baby, N59, is notable as being the first of an extremely select class of British warplane - the single-seat, flying-boat fighter. As was to be expected from Supermarine, the Baby was of very pleasing appearance with an elegant mahogany Linton Hope hull. The 200 h.p. Hispano-Suiza engine was installed between the folding biplane wings to drive a pusher propeller. Maximum speed at sea level when tested in February, 1918, was 117 m.p.h., combined with excellent handling and manoeuvrability. Six months later, in August, the Baby was tested also with the 200 h.p. Sunbeam Arab engine but no production of the machine was undertaken.
A more conventional approach to the same type of aircraft was visible in the Vickers E.F.B.1 which was displayed on the Company’s stand at the same 1913 Olympia Aero Show. The Vickers machine had been designed by A. R. Low and G. H. Challenger to meet the requirements of an Admiralty contract, which the firm had received on 19th November of the previous year, calling for an experimental biplane armed with a machine-gun for offensive use. Equipped also with the bellicose name Destroyer, the first example of the Gunbus series followed, too, the pusher style forcibly dictated by circumstances at the time for any gun-carrier. Constructed under Vickers number 18, the E.F.B.1 was given two-bay, staggered wing cellules of unequal span. Composite construction was employed, with wood being used mainly but with tubular steel forming the tail booms and duralumin the covering of the two- seat nacelle. No. 18’s engine was an eight-cylinder V, air-cooled Wolseley developing 80 h.p. with water-cooled valves. The Destroyer’s all-important armament consisted of a Vickers-Maxim machine-gun installed in the nose coaming and capable of being aimed through a slot with 60° vertical and horizontal movement. This form of mount was not particularly satisfactory with its restriction on speed and in freedom of movement of the gun. Belt-feeding of the cartridges proved particularly awkward, both in following the gun as it was swung and in storing satisfactorily in the limited space in the nose. The E.F.B.1 is thought to have crashed the first time that it left the ground but was believed to hold such prospects of ultimate success that a revised version was put in hand. The E.F.B.1’s important distinction is that it represented the first serious attempt at designing from the start a true fighting aeroplane for the British services without being compromised by being simply a modification of an existing airframe.
Vickers E.F.B.1
The second Experimental Fighting Biplane, the E.F.B.2, abandoned the staggered wings, surfaces and struts featured in its predecessor and received the extra power of a nine-cylinder 100 h.p. Monosoupape Gnome engine mounted at the rear of a shorter nacelle. At the forward end, the Vickers gun swivelled in a ball-and-socket type of mounting and the crew’s vision was given the added benefit of large transparent celluloid panels on each side of the nacelle. The tailplane was modified to have a curved leading-edge and twin skids in the undercarriage replaced the single one fitted to the E.F.B.1. Brooklands was the scene of the testing of the E.F.B.2 by R. H. Barnwell in October, 1913.
   With their E.F.B.3 No. 18B revised Gunbus, also at the Show, Vickers were more successful in that it was part of the developing series which finally went into production as the F.B.5. The E.F.B.3 still carried the single nose gun in a nacelle which was now without the side windows. Minor modifications compared with its predecessor, the E.F.B.2, were strut-connected ailerons, equal-span wings and no cut-out in the upper centre-section trailing-edge as the engine and propeller had been moved slightly further rearwards.
Vickers E.F.B.2 Gunbus of 1913.
E.F.B.3 with metal-sheathed nacelle at Brooklands in 1913 with Harold Barnwell, Vickers' chief pilot, in rear seat.
Appearing in 1914, the E.F.B.3 was the first Vickers warplane to achieve production.
Immediately following the E.F.B.3 came the E.F.B.4 which had fabric sides to the nacelle, cable-connected ailerons and wooden interplane, centre section and upright struts between the tail booms in place of metal used so far. The undercarriage was enlarged but perhaps the most significant difference was that the gun had been raised from its trunnion form of mounting onto a pillar to give completely free movement in aiming.
   The next Gunbus, the E.F.B.5, was the final prototype for the production F.B.5 and reverted to steel struts, combined with equal-span wings and curved tailplane. An official order had still not been received for the Gunbus but Vickers, sensing that war was but a short time away, took the step of putting a batch of fifty of the type into production on their own responsibility as the F.B.5. Once again the design was altered before it was ready for its tests at Farnborough in July, 1914. To simplify production a rectangular tailplane was substituted; wooden struts were fitted again and the vertical tail was of well-rounded outline. The Vickers-Maxim gun had not proved to be the handiest of weapons for such an installation and was replaced by the lighter and more flexible Lewis with its drum cartridge feed.
   In company with their fellow British aircraft constructors, the Vickers company continued their efforts to produce an effective fighting machine. Their F.B.5, after being used in small numbers by one or two squadrons flying with mixed types, finally reached the Front as the sole equipment of one unit when No. 11 Squadron, R.F.C., arrived on 25th July, 1915, soon after finding its feet with its sturdy pushers. Experimental versions of the F.B.5 Gunbus which appeared in mid-1915 included an armoured example, fitted with the first of the 110 h.p. Clergets to arrive in Britain, and two for the Admiralty - Nos. 1534 and 1535 - both fitted with the more powerful 150 h.p. Smith Static radial engine. All three remained as prototypes and the Vickers design staff turned their attention to something more advanced.
Vickers E.F.B.4, with gun mounting on nose.
Also in July, Vickers produced another single experimental version of the Gunbus series, the F.B.6. This used, too, the 100 h.p. Monosoupape Gnome and was basically a modified F.B.5 with extended upper wingtips braced by kingposts and wire. At the same time the shape of the rudder was revised.
The single experimental Vickers F.B.6 of 1914.
Two-seat Vickers Scout of 1914.
While Harold Barnwell was busy designing the E.S.1 and E.S.2 for Vickers, another of the prominent British pioneer designers, R. L. Howard Flanders, was working for the same firm on a commission for a twin-engine machine capable of mounting a Vickers 1-pounder quick-firing gun. The designation F.B.7 showed that the new aeroplane was the next in line as a Fighting Biplane after the experimental F.B.6. The F.B.7 was the first design from Howard Flanders since his B.2 biplane of mid-1912 and was commenced just after the start of the War, following his enforced break with aeronautics after a serious motor-cycle crash and his subsequent recuperation far away in Australia.
   The F.B.7, the first twin-engine aeroplane built by Vickers and among the earliest of multi-engine, two-seat gun-carriers, in general appearance displayed a very obvious connection with its designer’s earlier B.2. It inherited the same low-slung fuselage style, together with the deep fore-fuselage and triangular-section rear portion. The undercarriage, with its very wide track and prominent central skid also owed its inspiration to the B.2. Other features common to both were the outline of the comma-shaped rudder, lack of a fixed fin, and the braced overhang of the upper wings - a feature which was even more accentuated in the F.B.7.
   A pair of 100 h.p. Monosoupape Gnomes, mounted starkly in the gap between the wings, powered the 59 ft. 6 in. span biplane. The pilot was seated in a roomy cockpit to the rear of the wings, a position from which his forward view was comparatively poor and which deteriorated still further when voluminous cowlings were installed later to shroud the engines. The bluff nose of the broad fuselage provided ample room for the large gun and enabled the gunner, whose seat was attached direct to the weapon’s mounting, to turn horizontally through a complete circle.
   Following the F.B.7’s initial flight during August, 1915, it proceeded to the C.F.S. at Upavon for evaluation, which was followed quickly on the 20th of the same month for an order for twelve production examples.
   Before work commenced on the batch, several significant alterations took place in the design. The most important of these was the location of the pilot’s cockpit in a greatly improved position forward of the wings and in a fuselage of greatly changed structure. Gone was the old triangular section at the rear and its place was taken by a conventional rectangular structure. A less happy change was the substitution of two 80 h.p. Renault engines as a result of a shortage of Monosoupape Gnomes. Designated F.B.7A and numbered 5717, the unwieldy machine was hard put to it to achieve any worthwhile performance on even lower power than that of its original engines, which themselves had been of far lower output than required to give the reasonable speed and agility to be expected in such a type. Vickers were left with little choice but to stop work on an altogether unsatisfactory combination and the War Office agreed to the annulment of the contract.
   Following the unfortunate failure of their F.B.7 and F.B.7A, Vickers produced in November, 1915, another twin-engine tractor biplane gun-carrier. Once again, Monosoupape Gnomes of 100 h.p. each were fitted but, this time, the airframe which they powered was of far cleaner, more advanced and more compact design. The span was only 38 ft. 4 in. on the F.B.8’s upper planes of the two-bay wings, the lower surfaces of which were attached to the bottom longerons of the fuselage. The tandem cockpit arrangement, with a considerable gap between the position of the Lewis gunner in the nose and that of the pilot behind the wings, reverted to the form used in the F.B.7. The spinning rotary engines were liable to fling oil in all directions and the pair on the F.B.8 were surrounded by metal rings designed to mitigate the nuisance. The general lack of agility compared with that normally found in a single-engine fighter once again told against the F.B.8, as also did the gap between the crew’s positions, and so the design fell by the wayside.
The Vickers F.B.7, 2 100 b.p. Gnome monosoupape engines
Under Harold Barnwell’s direction a new tractor scout, the E.S.1, was designed and built. Powered by the 100 h.p. Monosoupape Gnome rotary, the machine was completed in August, 1915, and was a single-bay, equal-span, non-staggered biplane of very neat and refined aspect. The lines of the broad-chord cowling flowed back into the fuselage along formers and stringers applied over the main wooden fuselage rectangular structure. Taper was introduced aft of the cockpit but the practice of carrying to some distance to the rear of the engine the full circular section of the engine cowling resulted in a comparatively inferior view from the cockpit along the bulky nose portion. Nevertheless, the E.S.1’s streamlining endowed it with a creditable top speed of 114 m.p.h. at 5,000 ft., and earned it the soubriquet of the Barnwell Bullet. As No. 7509, the E.S.1 went to France for Service Trials with the R.F.C. but was ultimately written off in a crash.
   The machine’s excellent performance was obviously worth exploiting and a modified version, the E.S.2, was ready in September, 1915. In this, the squared-off wingtips of the E.S.l had been replaced with those of rounded outline and the pilot’s view which, in the earlier machine had been commented on adversely, was improved in an upward direction by the provision of a generous opening in the upper centre-section. Altered also were the lower portion of the fuselage which, in the E.S.2, was flat instead of rounded and resulted in decreased depth, and the 110 h.p. Clerget’s cowling which was of reduced chord.
   A positive attempt was made in the E.S.2 to produce a tractor scout equipped with a fixed forwards-firing gun. This was accomplished by mounting a Vickers gun in a trough to port in the upper decking and synchronizing it to fire between the propeller blades by incorporating the interrupter gear which had been produced by Vickers in collaboration with G. H. Challenger.
   Even though the E.S.2 possessed a good performance and a long-awaited answer to the old gun-aiming problem, the two built - 7759 and 7760 - remained as prototypes only. Despite its several attributes, the type was dogged by the relatively poor view from the cockpit, owing to the plumpness of the generous cross-section of the fuselage. Nevertheless, the E.S.2 was a commendable step in the right direction and provided Vickers with valuable experience which was put to good use later. As an alternative to the 110 h.p. Clerget, the le Rhone of the same power was tested also in the airframe.
Vickers E.S.2 7759.
In December, 1915, a month after the debut of the twin-engine F.B.8, another two-seat Vickers fighter appeared. This time it was the single-engine F.B.9 - a revised F.B.5. Significant alterations in the design, bestowing an altogether more rounded appearance, were the replacement of the square tips of all horizontal flying surfaces by those of curved outline, and the shapelier nose to the nacelle. The comparatively complex form of twin-skid undercarriage was supplanted by a much neater V type. At the rear of the nacelle was fitted the 100 h.p. Monosoupape Gnome while, at the front, the gunner was given a new form of rotating circular gun-ring with a corresponding increase in the effectiveness of the weapon it supported. Although the top speed, compared with that of the F.B.5, had increased by 10 m.p.h., the F.B.9 appears to have been used mainly as a training type.
Vickers F.B.9
The Vickers member of the trio of prototype escort fighter designs was the F.B.11, which appeared also in 1916. The Vickers product showed a far more restrained approach to the problem than its competitors, being basically a straightforward tractor biplane but following the same arrangement for the disposition of the crew of three as that adopted in the Sopwith L.R.T.Tr. The upper gunner was accommodated in his lofty perch above the upper wings in a less shapely nacelle than that of the Sopwith but the Rolls-Royce Mk.1 engine of 250 h.p. was endowed with a neat cowling and radiator installation. None of the proposed escort fighters went into production as the development of synchronizing gears nullified the requirement.
Vickers F.B.11 with gunner’s nacelle in upper centre-section.
Although by 1916 the tractor layout was firmly established as the optimum for most classes of aeroplane, Vickers pressed forward during the year with another single-seat pusher fighter - the F.B.12. A well-streamlined nacelle was carried between the two-bay wings, the whole machine being designed around the 150 h.p. Hart radial engine which was expected to endow the F.B.12 with a performance superior to that of other pusher fighters extant. The F.B. 12’s airframe was ready before any example of its intended engine so the 80 h.p. le Rhone served to flight-test the machine in June, 1916. As well as flying with the le Rhone engine, the F.B.12 flew with the more powerful 100 h.p. Monosoupape Gnome and tests were made with revised wings of larger size and more angular form. Armament in each version was a single Lewis gun set well back in the upper nose of the nacelle.
   Yet another version of the basic F.B.12 design, the F.B.12C, made its appearance. The scheduled engine was again the elusive 150 h.p. Hart radial but, once more, it failed to materialize and in its place the F.B.12C utilized both the 110 h.p. le Rhone and the 100 h.p. Anzani. The machine differed from the two previous F.B.12 designs in having a flat-sided nacelle in place of the circular type, and modified wings and tail. Although Service Trials were carried out at the end of the year, the pusher fighter was in eclipse and could not be expected to compete with the cleaner tractor types.
The F.B.12, A7351, with short span wings, after it had been fitted with a Gnome monosoupape engine; note the fixed Lewis gun in the nose.
Elliptical wing-tips distinguished the first F.B.12.
Vickers F.B.12C.
Home Defence was one of the spheres in which both types proved finally of some value and was a role in which a new Vickers two-seat, fighter reconnaissance tractor biplane, the F.B.14, also found itself performing. The 230 h.p. B.H.P. was the engine originally scheduled for the F.B.14 but delays in its development forced Vickers to install as an alternative the less-powerful 160 h.p. Beardmore. The combination made its first flight during August, 1916, but was unable to demonstrate a performance in keeping with that which had been expected using the intended power plant. In spite of this disappointment, an order was placed for one hundred and fifty. The F.B.14 was certainly to date the cleanest of Vickers two-seaters and in appearance looked a most promising aeroplane.
   The switch to the 160 h.p. Beardmore did not, however, prove to be the panacea as difficulties with it led to the trial installation of the even lower output 120 h.p. Beardmore. With this engine the F.B.14 was quite unable to reach its required standard of performance as an operational proposition and most of the airframes constructed were passed engineless to the War Office for the search to continue for a suitable power unit.
   The installation of the 150 h.p. Lorraine-Dietrich resulted in the F.B.14A, and another version with larger two-bay wings in place of the earlier single-bay type and powered by the excellent 250 h.p. Rolls-Royce Mk. IV was designated F.B.14D. The power contributed by the Eagle IV engine was responsible for the F.B.14D having the best performance of the F.B.14 series but, even so, the machine was still not able to surpass that of the redoubtable Bristol Fighter.
   Vickers produced one more version of the basic design in the 150 h.p. R.A.F.4a-powered F.B.14F, which had a simplified fuselage without the curved coaming on the top surface and wings set with substantially greater stagger. Both the F.B.14D and the F.B.14F were employed on experimental work but six F.B.14s were allocated in 1917 for Home Defence operations.
1916 was the year in which Vickers produced another single-seat fighter, the F.B.16, which was to undergo considerable development as a basic design. The F.B.16 was a neat and workmanlike single-bay biplane and was able to be fitted with the engine scheduled for it, the 150 h.p. Hart radial, which had had to be abandoned as the unit for the Vickers F.B.12. Modifications were made in the F.B.16, which included removal of the cowling over the engine, the rounding of the previously humped fin outline, the replacement of the two-blade propeller by a four-blader, and the fitting of a considerably smaller headrest for the pilot.
   Vickers decided to put in hand an extensive redesign of the F.B.16 which came into the open in December, 1916, as the F.B.16A. The new fighter was of quite pugnacious aspect with sharply-staggered wings mated to a straight-sided fuselage, in the nose of which was mounted the 150 h.p. Hispano-Suiza engine. The top and bottom of the fuselage were rounded and the fin and rudder outline followed that of the modified F.B.16. The undercarriage was set well forward and the single Vickers gun, as fitted also to the F.B.16, was mounted on the front decking. In addition, the F.B.16A carried a Lewis gun on the upper centre-section on a sliding mounting.
   Test flights on 20th December, 1916, carried out by Capt. Simpson, resulted in a fatal crash but Vickers constructed another F.B.16A, the trials of which R. H. Barnwell conducted. Despite the lively performance which the F.B.16A exhibited it was not to receive a production order.
   Nevertheless, Vickers continued to expend time and money in developing the design still further so that, by June of 1917, F.B.16A A8963 had been transformed into the F.B.16D. As well as minor modifications to the airframe, engine power was stepped up by installing the 200 h.p. Hispano-Suiza, the armament comprising a Lewis gun firing through the propeller shaft and a second gun of the same type on the upper centre-section. The F.B.16D would have stood a good chance of being adopted for Service use as its performance was excellent for its time but engine accessibility was considered to be below the standard necessary for field maintenance.
   Two other versions of the F.B.16 were to appear - the generally-larger F.B.16E with two-bay wings, 275 h.p. Lorraine-Dietrich engine and two fuselage-mounted Vickers guns, and the F.B.16H which was similar to the F.B.16E but had even greater power from a 300 h.p. Hispano-Suiza engine which brought its speed at ground level to 147 m.p.h.
Vickers F.B.16D.
Vickers F.B.16H.
August, 1916, saw the emergence of the F.B.19 Mk.I, another of Vickers Ltd.’s endeavours in single-seat fighter design. The new machine was basically the resuscitation of the E.S.1 and E.S.2 of the previous year but with a slightly smaller span and reduced overall length. The F.B.19 Mk.I’s engine was the 100 h.p. Monosoupape Gnome and the armament provided was a single Vickers gun, mounted to port in a trough in the fuselage, and synchronized with the Vickers-Challenger gear.
   A new version then appeared, designated F.B.19 Mk.II, the wings of which embodied sharp stagger, and which used either the 110 h.p. Clerget or the 110 h.p. le Rhone engine.
   The Mk.I could also utilize the 110 h.p. le Rhone and both marks of F.B.19 went into limited production against orders for the R.F.C., by which service it was often called the Bullet. After being turned down for full-scale operation in France, the F.B.19 found itself flying in the Middle East and also with Home Defence units in the United Kingdom but was never fortunate enough to make a name.
Vickers F.B.19 Mk.II.
In their endeavours to produce a successful two-seat tractor fighter, Vickers evolved several variants of their basic F.B.24 design. The machine was first discussed at the end of 1916 as a fighter reconnaissance biplane to be designed around the 150 h.p. Hart radial engine but finally appeared in 1917 with the 200 h.p. Hispano-Suiza installed and designated F.B.24B. Its appearance was that of a normal unequal-span two-bay biplane with rather angular and inharmonious lines.
   A new version, the F.B.24C, made its bow with the 285 h.p. Lorraine-Dietrich 8Bd engine and embodied a modified fin of smaller size, besides being tried out with a pair of side radiators as an alternative to the frontal type.
   The field of view from the pilot’s cockpit under the upper centre-section was considered to be far too restricted for a fighting aircraft and an attempt was made in the F.B.24E to rectify the fault by raising the fuselage to the level of the upper wings and filling the resulting gap below the fuselage to the lower planes with the Hispano-Suiza’s radiator. The pilot’s upward view was vastly improved but at the expense of his downward vision.
   The general layout of the F.B.24E was carried forward into the F.B.24G which was given larger wings of equal span and the 375 h.p. Lorraine-Dietrich 13 as its power unit with two side-mounted radiators. None of the F.B.24 variants was eventually accepted for service.
Vickers F.B.24C.
Vickers suffered equally bad luck with their F.B.25 which reverted to the pusher biplane layout for a two-seat, anti-Zeppelin fighter. The broad nacelle housed two separate side-by-side cockpits, that to starboard being set in advance of the other. The rear of the nacelle contained a 150 h.p. Hispano-Suiza engine, in lieu of the intended 200 h.p. version of the same engine which was unobtainable for the machine. A single Vickers Crayford rocket gun was intended to be the F.B.25’s armament and, as an aid to night operations, a searchlight was fitted in the prow of the nacelle.
   The F.B.25 made no headway as it crashed at Martlesham Heath during trials which had already disclosed that its response to its controls was very poor, causing its demise.
May, 1917, was the month of the appearance of yet another ill-fated Vickers single-seat pusher fighter - the F.B.26 Vampire. Although very similar in general appearance to the same firm’s F.B.12 of the previous year, the Vampire had twice as much power in its 200 h.p. Hispano-Suiza engine and was rather larger and heavier. The two-bay style of wing cellule was retained with the nacelle fitted direct to the underside of the upper planes. A pair of Lewis guns in the nose of the nacelle armed the first F.B.26 but, after alterations to the wings, the cooling system and the vertical tail surfaces, the Vampire’s offensive power was increased by a third Lewis gun, the trio being on an Eeman mounting. The triple installation was tested both high up and low down in the nacelle, trials also being made with night-flying equipment installed.
   Although, the following year, one of the Vampires - B1485 - appeared as the F.B.26A Vampire Mk.II, powered by the 230 h.p. Bentley B.R.2 rotary, with an armoured nacelle and twin Lewis guns for use as a trench-fighter, development was cancelled in favour of the rival Sopwith firm’s Salamander.
The approach of the third firm, Westland, to the N.1B conditions took the form of a single-seat, tractor biplane on floats. R. A. Bruce and A. Davenport designed the machine which was intended to be operated from ships. Two prototypes, N16 and N17, were constructed, the engines chosen in each case being the 150 h.p. Bentley B.R.I. N16 used Sopwith floats, including the usual one at the tail. N17 differed in being equipped at first with a pair of long Westland-built floats which made a tail float unnecessary but the machine flew later with main and tail Sopwith floats. Tests were carried out in October, 1917, and the Westland N.1Bs were armed with one Vickers gun on the front decking and one Lewis on the upper centre-section. Although performance and handling were good, the landplane Pups and Camels were considered better for the purpose of sea operations and Westland’s N.1Bs were abandoned.
N17, the second Westland N.1B, equipped with long Westland floats.
Westland’s contribution to the series of R.A.F. Type 1 prototype fighters was provided by their design team of Bruce and Davenport and appeared in 1918 as the Wagtail. An appealing and shapely little biplane of 23 ft. 2 in. span, it mounted the 170 h.p. A.B.C. Wasp 1 engine, a unit which was one of the troublesome radials of the last part of the 1914-18 War. Construction of the Wagtail followed the usual form for a wood and fabric biplane but in its finely-conceived and balanced proportions the machine possessed an attractiveness matched by few others. Two Vickers guns on the front decking provided the Wagtail’s firepower and its maximum speed at 10,000 ft. was 125 m.p.h. Five were constructed but as prototypes only.
Side View of a Westland "Wagtail" Single-seat fighter. (170 h.p. A.B.C. Wasp engine.)
Westland Wagtail C4293.
The Westland designers Bruce and Davenport were responsible for a two-seat fighter reconnaissance biplane which the West Country firm completed towards the end of 1918. Called the Weasel, the machine was of typical two-bay layout but was one of the unlucky types to have the unreliable A.B.C. Dragonfly 1 engine of 320 h.p. Two Vickers guns were provided for the pilot and the observer used a single Lewis on a Scarff ring. The Weasel was quite successful in flight trials but the four built spent their lives in experimental work only.
Another little-known single-seat fighter design which came to naught was the Whitehead Comet of 1916. An 80 h.p. le Rhone was fitted to the single-bay, staggered biplane which had a well-formed fuselage of circular section but an indifferent view from the cockpit.
Yet another of the unsuccessful single-seat scout prototypes of 1916 was the Wight Baby of J. Samuel White and Company of Cowes. This was a 100 h.p. Monosoupape Gnome-powered single-bay biplane which embodied the double-camber wing section evolved by Howard Wright, and folding wings.
J. Samuel White were among the few aircraft companies to attempt to exploit the quadruplane form and did so with their single-seat scout of 1916. The three upper wings were equal in span but the lowest was shorter than the others. Differing chords on each set of wings were incorporated and the 110 h.p. Clerget-engined machine was modified several times in efforts to improve it but N546 remained the only example of one more of the various unacceptable quadruplane types built.