Vickers EFB3 and SB1

An experimental two-seat fighter of Gunbus layout and a training aircraft derived from it.
 

Vickers EFB3


The Vickers EFB3 (Experimental Fighting Biplane) was a development of the EFB2 (described separately) and was the immediate predecessor of the successful Vickers FB5 Gunbus fighter.
 
Vickers EFB3 metal shelled nacelle at Brooklands 1913 The Vickers EFB3 at Brooklands in 1913.
 
The Vickers EFB3 was a single-engine pusher biplane designed to carry a Vickers 0.303 inch machine gun in the extreme nose. As with the earlier Vickers EFB2, this gun was mounted on trunnions in the extreme nose. It was articulated, providing a somewhat restricted field of fire.
 
The Vickers EFB3 was powered by a 100 hp Gnome monosoupape rotary engine, driving a two-blade propeller. The aircraft fuselage structure was all-metal and steel interplane struts were used. The main differences from the Vickers EFB2 were that the engine was moved rearward, so that no cut-out for the propeller was required in the upper wing.
 
In consequence, the crew nacelle was lengthened, with the crew moved forward to bring the centre of gravity back to its previous position. Ailerons were installed on the upper wings, in place of wing warping. The transparent cockpit side panels, that were to become a feature of the Vickers EFB2, were removed after being declared unnecessary.
 
During its initial trials, the Vickers EFB3 was modified to receive new vertical tail surfaces of a triangular shape, with a fixed fin forward of a revised rudder.
 
Vickers EFB3 stbd rear Brooklands Jun 1914 new fin An experimental Vickers EFB3 at Brooklands in June 1914 with a modified fin and rudder..
 
The Vickers EFB3 attracted the attention of the Admiralty, who placed an order for twelve production aircraft as the Admiralty Type 18B. With the outbreak of the First World War, this contract was taken over by the War Office, which led to a significant redesign, with the final production configuration becoming the Vickers FB5 Gunbus (which is described elsewhere on this website).
 
The twelve initial production aircraft were allocated serial numbers 861 to 872 before completion as Vickers FB5 Gunbus aircraft.
 
 

Vickers SB1


The Vickers SB1 (School Biplane 1) was a derivative of the Vickers EFB3, with a new crew nacelle.
 
For obvious reasons the gun armament was removed and the front cockpit fitted with dual controls. The nacelle was also raised slightly above the lower wing on short struts. Power was provided by a 100 hp Anzani radial engine.
 
The photograph below, from the Vickers archive, is identified as being the SB1 and generally conforms to the above description. However, the undercarriage design differs markedly from that of the Vickers EFB3. Some references suggest that the Vickers SB1 was designed but not actually built, so it remains possible that this image has been misidentified in the archive. The photograph was however, clearly taken at Brooklands.
 
Vickers EFB3 SB1 stbd rear The Vickers SB1 was derived from the EFB3 as a possible training aircraft.
 

Variants & Numbers


One prototype EFB3 believed to have been modified and converted to become the EFB5 (prototype for the FB5 Gunbus). 12 production aircraft ordered by the Admiralty believed completed as FB5. One SB1 training derivative.
 

Specification (EFB3)


Powerplant
Ome 100 hp Gnome Monosoupape
Span
37 ft 4 in
Maximum Weight
1,680 lb
Capacity and Armament
Pilot and gunner; one Vickers machine gun fired from the front cockpit
Maximum Speed
60 mph at sea level
Range
300 miles
 

Survivors


No examples of the Vickers EFB3 or SB1 survive.

Other information