The Bristol Scout was designed in the second half of 1913 by
Frank Barnwell and
Harry Busteed, Bristol's chief test pilot, who thought of building a small high-performance biplane while testing the
Bristol X.3 seaplane, a project which had been designed by a separate secret design department headed by Barnwell. The design was initially given the works number SN.183, inherited from a cancelled design for the Italian government undertaken by
Henri Coanda, the half-finished fuselage of which remained in the workshops and the drawings for the aircraft bore this number. The design was an equal-span single-bay biplane with staggered parallel-chord wings with raked wingtips and
ailerons fitted to the upper and lower wings, which were rigged with about half a degree of
dihedral, making them look almost straight when viewed from the front. The wing section was one designed by Coanda which had been used for the wings of the
Bristol Coanda Biplanes. It was powered by an 80 hp (60 kW)
Gnome Lambda rotary engine enclosed in a
cowling that had no open frontal area, although the bottom was cut away to allow cooling air to get to the engine. It had a rectangular balanced
rudder with no fixed
fin and split elevators attached to a non-lifting horizontal stabiliser. The fixed horizontal tail surfaces were outlined in steel tube with wooden ribs and the elevators constructed entirely of steel tube. The first flight was made at Larkhill on 23 February 1914 by Busteed and it was then exhibited at the March 1914 Aero Show at
Olympia in London. After more flying at Larkhill the prototype, later referred to as the
Scout A, was returned to the factory at
Filton and fitted with larger wings, increasing the
chord by six inches (15 cm) and the span from 22 ft (6.71 m) to 24 ft 7 in (7.49 m). These were rigged with an increased dihedral of °. Other changes included a larger rudder, a new open-fronted cowling with six external stiffening ribs distributed in symmetrically uneven angles around the cowl's sides (especially when seen from "nose-on") and fabric panel-covered wheels. It was evaluated by the British military on 14 May 1914 at
Farnborough, when, flown by Busteed, the aircraft achieved an airspeed of 97.5 mph (157 km/h), with a stalling speed of 40 mph (64 km/h) The aircraft was then entered for the 1914
Aerial Derby but did not take part because the weather on the day of the race was so poor that Bristol did not wish to risk the aircraft. By this time two more examples (works nos. 229 and 230) were under construction and the prototype was sold to
Lord Carbery for £400 without its engine. Carbery fitted it with an 80 hp
Le Rhône 9C nine-cylinder rotary and entered it in the London–Manchester race held on 20 June but damaged the aircraft when landing at
Castle Bromwich and had to withdraw. After repairs, including a modification of the undercarriage to widen the
track, Carbury entered it in the London–Paris–London race held on 11 July but had to ditch the aircraft in the English Channel on the return leg; while in France, only one of the two fuel tanks had been filled by mistake. Carbury managed to land alongside a ship and escaped but the aircraft was lost. Numbers 229 and 230, later designated the
Scout B when Frank Barnwell retrospectively gave type numbers to early Bristol aircraft, were identical to the modified Scout A, except for having half-hoop-style underwing skids, what appear to be six stiffening ribs positioned around the engine cowl's exterior circumferential surface (also made with a larger circular front opening for engine cooling when compared to the Scout A) and an enlarged rudder. Completed shortly after the outbreak of war in August 1914, they were requisitioned by the War Office. Given
Royal Flying Corps serial numbers 644 and 648, one was allocated to
No. 3 Squadron and the other to
No. 5 Squadron for evaluation. The production aircraft, later called the
Scout C, differed from their predecessors mainly in constructional detail, although the cowling was replaced by one with a small frontal opening and no stiffening ribs, the top decking in front of the cockpit had a deeper curve and the aluminium covering of the fuselage sides extended only as far as the forward centre-section struts, aft of which the decking was plywood. ==Operational history==