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 100hp Gnome Monosoupape rotary was retained as was also the 7.7mm 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 80hp 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.

Engine: 100hp Gnome Monosoupape
Max take-off weight: 762 kg / 1680 lb
Empty weight: 476 kg / 1049 lb
Wingspan: 11.38 m / 37 ft 4 in
Length: 8.38 m / 28 ft 6 in
Height: 2.97 m / 10 ft 9 in
Wing area: 35.77 sq.m / 385.02 sq ft
Max. speed: 97 km/h / 60 mph
Range: 483 km / 300 miles

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 100hp Gnome Monosoupape nine-cylinder rotary engine was fitted. The 7.7mm 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 take-off weight: 798 kg / 1759 lb
Empty weight: 476 kg / 1049 lb
Wingspan: 11.76 m / 39 ft 7 in
Length: 8.89 m / 29 ft 2 in
Height: 2.92 m / 10 ft 7 in
Wing area: 35.30 sq.m / 379.97 sq ft
Max. speed: 97 km/h / 60 mph
Range: 241 km / 150 miles

On 19 November 1912, Vickers received a contract from the Admiralty for an experimental fighting biplane armed with a machine gun. Various configurations were investigated before the desirability of placing the gunner in the extreme nose of the aircraft, in order to achieve a clear field of fire, led to choice of a fuselage nacelle carrying at its rear an engine driving a pusher propeller. This nacelle was mated with an unequal-span heavily-staggered biplane configuration, the tail surfaces being carried by paired and vertically disposed booms attaching to the upper and lower rear wing spars on each side of the engine.

Designated E.F.B. (Experimental Fighting Biplane) 1 and dubbed “Destroyer”, the Vickers aircraft was armed with a single 7.7mm Maxim machine gun on a mount affording 60 degrees elevation and traverse. The airframe of the E.F.B.1 was primarily of metal construction, the nacelle accommodating the pilot and gunner, and carrying an 80hp Wolseley eight-cylinder Vee-type engine, being of steel tube with duralumin skinning. Wing warping was employed for lateral control.

Prior to its first flight, the E.F.B.1 was displayed at the Aero Show held at Olympia, London, in February 1913.

The gun was fitted for the first flight test, made at Joyce Green, but this rendered the aircraft so nose-heavy that it briefly left the ground, then nosed down, struck the ground and turned over.

Max take-off weight: 1207 kg / 2661 lb
Empty weight: 798 kg / 1759 lb
Wingspan: 12.19 m / 40 ft 0 in
Length: 8.38 m / 28 ft 6 in
Height: 3.63 m / 12 ft 11 in
Wing area: 35.77 sq.m / 385.02 sq ft
Max. speed: 113 km/h / 70 mph

The 1913 Vickers No. 26 “Pumpkin” biplane was designed and built by Vickers Aircraft.