M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)

P.Lewis British Aircraft 1809-1914 (Putnam)

Vickers Gunbus E.F.B.1 to F.B.6

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   The E.F.B.1 is believed to have crashed on its first test flight, but, as the design was considered promising, development proceeded into the E.F.B.2. This was given extra power with the installation of the nine-cylinder 100 h.p. Monosoupape Gnome in a nacelle which had been shortened at the rear, compared with that of the E.F.B.1. Another great difference between the two machines was the abandonment in the E.F.B.2 of the "all-staggered" look of its predecessor by the use of unequal-span unstaggered wings and of vertical struts and rudder. A tailplane with a curved leading-edge took the place of the rectangular one of the first machine, and crew vision was improved with a pair of large celluloid windows let into each side of the nacelle. Testing of the E.F.B.2 was carried out at Brooklands during October, 1913, by R. H. Barnwell.
   Second thoughts about the Gunbus design were apparent in the E.F.B.3 No. 18b exhibited at the Olympia Aero Show of 1914. Strut-connected ailerons were introduced on the four wing-tips and the mainplanes were of equal span. The propeller cut-out in the upper centre section was deleted, as the engine had been moved a little towards the rear. Another omission was that of the side windows in the nacelle.
   Following the E.F.B.3 came the E.F.B.4, which differed in detail. The sides of the nacelle were covered with fabric, and the gun was taken out of the trunnion mounting to be raised on to a pillar mounting to fire over the coaming for better sighting and manipulation. The oil tank was resited over the nacelle for improved control of the C.G. and the ailerons were connected by cables instead of struts. The interplane, centre-section and undercarriage struts, and the uprights between the tail booms, were made of wood in place of the metal struts used on the earlier machines of the series. The undercarriage also was revised by increasing the distance between the uprights and by lengthening the pair of skids.
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H.King Armament of British Aircraft (Putnam)

The Admiralty mounting consisted of a cradle or frame which could rock in a vertical plane and also rotate in azimuth. At one end of this member, the gun was carried on a universal joint; at the other end was the gunner's seat. The cradle was curved in form and was mounted on a horizontal pivot carried in a bracket which itself had a vertical swivelling pin stepped in a socket attached to the aircraft structure. A handwheel operating a worm gear was provided for traversing.
Whether this mounting was ever installed in an aircraft the present writer does not pretend to know; but the mounting identified with the next airframe development (E.F.B.2) was designed by Vickers themselves, and is likewise illustrated. In this installation the gun projected through the nose, somewhat as on the Destroyer, but the gap was closed by a shield of hemispherical form which moved with the gun both in elevation and traverse. This shield was primarily to protect the gunner from the airstream and to afford a good aerodynamic form for the nacelle nose, but the possibility of making it bullet-proof was considered. The mounting embodied a cross-head which carried the gun and was provided with a 'training pivot' mounted in a socket bolted to the forward portion of the fuselage. A plate having a curved slot concentric with the gun trunnions was attached to the gun and a clamp was provided by which the plate could be locked to the cross-head with the gun at any desired angle of elevation. The socket could also be fitted with a clamp for holding the cross-head rigid with the socket when the gun was not in use. Mention was made by Vickers of 'transparent sight openings in the hemispherical shield' and the form of the sight is shown in the drawing. The backsight was adjustable over a vertical scale.
The possibility of armouring has already been mentioned, and armoured Gun Buses were actually built. In this context reference may be made to a paper read early in 1913 by Maj F. H. Sykes. Commander of the Military Wing of the RFC, calling for #a two-seater fighting machine to carry a gun, ammunition, light armour and petrol for 200 miles'. Present on that occasion was Capt (later Maj) Herbert F. Wood, who was very closely connected with the development of the Gun Bus series and who remarked that, although Maj Sykes had stated that 'the armoured aeroplane could not lift as fast as the smaller machine', he was not sure that this were not possible if speed were sacrificed. 'Because such a machine would be used purely as a defensive factor against foreign flying machines.' he said. #it ought to be possible to get sufficient speed for a short time by diving.' A similar practice was enforced upon Fury, Gauntlet and Gladiator pilots when the Blenheim bomber came in.
The 'transparent sight openings# mentioned by Vickers. in connection with the hemispherical shield-type mounting described, were in evidence on the E.F.B.3 when it appeared at Olympia in 1914. It was reported:
'In the nose of the nacelle, and mounted on a universal joint resting on the tubular framework, is a Vickers Automatic Rifle Calibre gun which had a range of action of 30 degrees in any direction from the line of flight. The gun projects through a circular opening, whilst a hemispherical shield is mounted on and moves with the gun barrel. This shield is fitted with mica windows, through which the gunner obtains his sights. This arrangement enables the gunner to operate the gun without the draught of wind interfering with the sighting of it.'
The ammunition supply was stated to be 300 rounds. Another report stated that the gunner was protected not only from the wind but from the gases from the gun when in action.
That this mounting constituted the first gun turret for aircraft can hardly be denied.

P.Lewis The British Fighter since 1912 (Putnam)

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.
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   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.

F.Mason The British Fighter since 1912 (Putnam)

Vickers E.F.B.2

   Even before the Vickers E.F.B.1 was lost early in its flight trials, Archibald Low was at work on a new design in a further attempt to meet the Admiralty’s requirement for a gun carrier. Not satisfied with the new Wolseley engine, he now turned to the Gnome monosoupape nine-cylinder rotary, claimed by its manufacturers to develop 100hp. This aeroplane, the E.F.B.2, featured wings of slightly reduced span and overhang, and without stagger, the interplane struts, tail boom struts and stern post all being vertical. The large tailplane was now almost semi-circular in plan, and the single central landing skid gave place to a pair of skids located immediately inboard of the wheels.
   An unusual feature was the inclusion of a pair of huge celluloid windows on each side of the nacelle, while the decking immediately forward of each cockpit coaming was also transparent. A trunnion-mounted Vickers-Maxim machine gun, with limited arcs of fire, was incorporated in the extreme nose - but in such a position that prevented accurate aiming.
   From all accounts the E.F.B.2 was pleasant to fly, being flown frequently during the second half of 1913 at Brooklands by Capt Herbert F Wood, Vickers’ technical adviser, and by Harold Barnwell, the company’s chief pilot. It was clear, however, that the Gnome monosoupape was not giving anything like its widely advertised power, and the E.F.B.2’s performance was disappointing, failing even to match that of the earlier aircraft. Nevertheless, the aeroplane went a long way in encouraging Low to persevere with the Gunbus formula, backed strongly by Capt Wood.
  

   Type: Single pusher engine, two-seat fighting biplane.
   Manufacturer: Vickers Ltd (Aviation Dept), Knightsbridge, London.
   Powerplant: One 80hp Gnome monosoupape nine-cylinder air-cooled rotary engine driving two-blade pusher propeller.
   Structure: Predominantly steel-tubular construction with fabric-covered wings and tail, and duralumin-covered nacelle; twin skid-and-wheel undercarriage.
   Dimensions: Span, 38ft 7in; length, 29ft 2in; height, 9ft 7in; wing area, 380 sq ft.
   Weights: Tare, 1,050 lb; all-up, 1,760lb.
   Performance: Max speed, 60 mph at sea level; initial climb, 200 ft/min; endurance,2 1/4 hr.
   Armament: Single trunnion-mounted 0.303in Vickers-Maxim machine gun in extreme nose of nacelle.
   Prototype: One. No production.


Vickers E.F.B.3

   Third and last of Archibald Low’s Gunbus designs for Vickers was the E.F.B.3 (or Vickers Type 18B), displayed at the Fifth Olympia Aero Show on 16 March 1914. Convinced that with only minor improvements in the E.F.B.2 his new design would secure a production order from the War Office (for the Admiralty appeared to be showing preference for Sopwith and Short gun carriers), Low determined to improve the efficiency of the upper wing by eliminating the trailing edge cut-out. This necessitated moving the engine aft by about nine inches to allow clearance for the propeller; in order to counteract the shift of c.g., this in turn required moving the crew correspondingly forward.
   The transparent panels in the sides of the E.F.B.2’s nacelle were discarded as largely superfluous; steel structural components were used throughout (except for wing and tail surfaces); and the ailerons on top and bottom wings were interconnected by steel struts, replacing wing warping.
   Other features of the E.F.B.2 were retained, including the trunnion-mounted front gun and identical tailplane and rudder; yet, despite the alterations to the nacelle, the E.F.B.3 was marginally shorter and lighter than its predecessor. It was therefore difficult to reconcile that the speed performance was not noticeably better. In the course of flight trials a new vertical tail surface was fitted, comprising a fixed triangular fin forward of the sternpost and a revised rudder.
   Notwithstanding the Admiralty’s interest elsewhere, twelve production E.F.B.3s were ordered, but before they were completed they were taken over by the War Office, and an extensive redesign undertaken - which emerged as the E.F.B.5. Although the unofficial name Gunbus had been in use for some months in the Vickers works, it was now formally adopted, despite the fact that Sopwith (also using the Brooklands flying field) was using the same name for that company’s similar aircraft.

   Type: Single pusher engine, two-seat, two-bay fighting biplane.
   Manufacturer: Vickers Ltd (Aviation Dept), Knightsbridge, London.
   Powerplant: One 100hp Gnome monosoupape nine-cylinder air-cooled rotary engine driving two-blade pusher propeller.
   Structure: All-steel structure with metal-clad nacelle; fabric-covered wings and tail surfaces. Twin wheel-and-skid landing gear.
   Dimensions: Span, 37ft 4in; length, 27ft 6in; height, 9ft 9in; wing area, 385 sq ft.
   Weights: Tare, 1,050lb; all-up, 1,680lb.
   Performance: Max speed, 60 mph at sea level; climb, 300 ft/min: range, 300 miles.
   Armament: One 0.303in Vickers machine gun on trunnion mounting in the nose of the nacelle.
   Prototype and Production: One prototype which circumstantial evidence suggests later became the prototype E.F.B. 5, with serial number 32; twelve aircraft, Nos. 861-872, were ordered by the Admiralty, but taken over by the War Office before completion, probably as F.B.5s.

W.Green, G.Swanborough The Complete Book of Fighters

VICKERS E.F.B.2 UK

   Following the loss of the E.F.B.1, Vickers undertook major redesign of its gun carrier while retaining the basic configuration to result in the E.F.B.2, again against an Admiralty contract. The E.F.B.2 eliminated the wing stagger of the previous aircraft and increased the span of the lower wing while retaining warping for lateral control. The fuselage nacelle was redesigned and large celluloid windows were inserted in its sides; the angular horizontal tail surfaces gave place to surfaces of elliptical form and a 100 hp Gnome Monosoupape nine-cylinder rotary engine was fitted. The 0.303-in (7,7-mm) machine gun on a ball-and-socket mounting in the forward cockpit was retained, and the E.F.B.2 entered flight test at Bognor in the autumn of 1913, but crashed there during the course of October.

Max speed, 60 mph (97 km/h) at sea level.
Initial climb, 200 ft/min (1,02 m/sec).
Range, 150 mis (241 km).
Empty weight, 1.050 lb (476 kg).
Loaded weight, 1,760 lb (798 kg).
Span, 38 ft 7 in (11,76 m).
Length, 29 ft 2 in (8,89 m).
Height, 9 ft 7 in (2,92 m).
Wing area, 380 sqft (35,30 m2)


VICKERS E.F.B.3 UK
  
   In December 1913, a third Vickers Experimental Fighting Biplane, the E.F.B.3, made its debut. The slight overhang of the top wing was eliminated to result in an equi-span biplane, the fuselage nacelle underwent further redesign, the celluloid windows being eliminated, and, most important, ailerons on both upper and lower wings supplanted the wing-warping control of its predecessors. The 100 hp Gnome Monosoupape rotary was retained as was also the 0.303-in (7,7-mm) Vickers gun. Displayed at the Aero Show held at Olympia in 1914, the E.F.B.3. was the subject of an order from the Admiralty for six aircraft placed in December 1913. This contract was subsequently taken over by the War Office, the six aircraft embodying a number of modifications - at least one was fitted with an eight-cylinder Vee-type 80 hp Wolseley engine - and being referred to as the Vickers No (or Type) 30. These were to lead in turn to the E.F.B.5 and F.B.5 Gunbus. The following data relate to the early E.F.B.3 with Gnome engine.

Max speed, 60 mph (97 km/h) at sea level.
Initial climb, 300 ft/min (1,52 m/sec).
Range, 300 mis (483 km).
Empty weight, 1,050 lb (476 kg).
Loaded weight, 1,680 lb (762 kg).
Span. 37 ft 4 in (11,38 m).
Length, 27 ft 6 in (8,38 m).
Height, 9 ft 9 in (2,97 m).
Wing area, 385 sq ft (35,77 m2).

Журнал Flight

Flight, March 14, 1914.

WHAT THERE WILL BE TO SEE AT OLYMPIA.

THE EXHIBITS.

Vickers (Vickers, Ltd.). (66.)

   THERE will be two machines exhibited by Messrs. Vickers on their stand, one of which will be a two-seater fighting biplane with the engine and propeller to the rear of the wings, while the other will be a tractor biplane. The former will be constructed of steel practically throughout, as the main spars, fuselage and landing chassis are made of that material, and only the ribs and skids are manufactured from wood, as was the case with the fighting machine shown last year. This machine will have a Maxim gun fitted in the front, the gunner occupying the front seat and the pilot the rear. Various improvements have, however, been made in the design of this machine, and these we shall deal with fully in subsequent numbers of FLIGHT.
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Flight, March 21, 1914.

THE OLYMPIA EXHIBITION.

THE EXHIBITS.

VICKERS (VICKERS, LTD.). (66.)

   Two machines are exhibited on the Vickers stand - one a 100 h.p. fighting "pusher" biplane, whilst the other is a fast scouting tractor biplane. The 100 h.p. Fighting Biplane is of a somewhat similar type to the one exhibited at Olympia last year, with the exception that this machine has not staggered planes. It is driven by a 100 h.p. Gnome monosoupape engine, mounted on overhung bearings in the rear of the nacelle. The latter structure is made throughout of steel tubes covered with aluminium. In the nose of the nacelle, and mounted on a universal joint resting on the tubular framework, is a Vickers Automatic K.C. gun, which has a range of action of 30 degrees in any direction from the line of flight. The gun projects through a circular opening in the nose of the nacelle, whilst a hemispherical shield is mounted on and moves with the gun barrel. This shield is fitted with mica windows, through which the gunner obtains his sights. This arrangement enables the gunner to operate the gun without the draught of wind interfering with the sighting of it. The seats, which are of the bucket type, are arranged tandem fashion, the passenger, of course, occupying the front seat. The pilot controls the machine by means of a wheel mounted on a tubular bridge of inverted U-shape. Rotation of the wheel operates the ailerons, whilst a to-and-fro movement actuates the elevator. The rudder is worked by a pivoted foot-bar.
   The chassis is of a different type to last year's model. It consists of two ash skids, carried on four streamline steel tube struts. A tubular axle, streamlined with wood, is slung from the skids by rubber cord. This machine is built of steel practically throughout, with the exception of the wings, which have spars of I-section spruce, with ribs built up of three-ply webs and ash flanges. The lower plane is attached to the nacelle by fitting the spars into steel tube sockets running right across the nacelle. Streamlined steel tube struts separate the main planes, the whole being made rigid by means of stranded cables which are all in duplicate. The angle of incidence is 440, and the planes are set at a dihedral angle of 1°.
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Flight, June 26, 1914.

EDDIES.

   BROOKLANDS was the scene, on Saturday last, of great activity, though of a different kind from that which usually takes place there. Posters along the footpath from Weybridge station to the entrance gates announced a Red Cross Field Day, and a Red Cross Field Day it was. The slopes around the paddock and test hill were covered with Red Cross hospitals and tents, whilst Territorial troops livened things up by conducting a fierce "battle." It was amusing to watch a division of the defending Army scramble up the steep parts of the race track, the surface of which was obviously not designed for this sort of exercise, the majority of the "Terriers" evidently not having taken the precaution of fitting "non-skids." Ultimately, however, the top of the track was reached and from here a deadly hail of wax bullets were rained down on an imaginary enemy.
   Mr. Barnwell, on the Vickers gun-carrying biplane, went out over the surrounding country to locate the enemy, and his passenger did his level best to kill off as many of the "invaders" as possible with the machine gun which was mounted in the nose of the nacelle. Later Barnwell must have regretted his part of the manslaughter for he went out again to look for "wounded," and after locating them brought back information as to their whereabouts, and thus probably saved many lives by enabling the field ambulance to render prompt assistance. Among the large and distinguished company which watched the proceedings during the afternoon were H.M. Queen Alexandra and the Dowager Empress of Russia, this being the first visit of a member of the British Royal Family to the track. Numerous flights were also made during the afternoon by Messrs. Mahl, Gower, Wilberforce, and several other pilots. In the evening Hawker arrived from Hendon, and delighted everybody by looping in excellent style.