P.Lewis The British Fighter since 1912 (Putnam)

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.

F.Mason The British Fighter since 1912 (Putnam)

Bristol Type 8 S.2A

   Once the Bristol Type 6 T.T.A. had passed out of the design stage, Frank Barnwell turned his attention to another original idea to overcome the lack of a reliable synchronized front gun, this time producing what was in effect a two-seat development of the Scout D, but instead of pursuing the customary tandem cockpit layout, which would be expected to require lengthening the fuselage by several feet, he adopted side-by-side accommodation of the crew in a single cockpit. While the pilot could concentrate on controlling the aircraft, his gunner could load, aim and fire the armament.
   Two prototypes, Nos 7836 and 7837, were produced to meet an Admiralty requirement for a two-seater, and the first was flown at Filton in May 1916. Powered by a 110hp Clerget rotary, it featured the tail unit of the Scout D as well as similar wings, though with reduced rake at their tips. The centre section of the upper wing was somewhat wider than on the Scout owing to the increased fuselage width, while the cabane struts were angled outwards, but without stagger; because the lower wing was mounted slightly further aft, stagger was maintained on the interplane struts. The broader fuselage also allowed for a wider track undercarriage.
   As neither prototype was ever fitted with armament, it is not known what gun mounting was intended, although it seems probable that the gun would have been fitted on top of the wing to fire over the propeller.
   The S.2A was not adopted for production, despite a moderately good performance, having been overshadowed by the Sopwith Pup with synchronized front gun. Trouble had been experienced with the Clerget engine in the first prototype, possibly due to inadequate cooling, and the second prototype was later flown at Gosport with the Gnome monosoupape engine.


   Type: Single-engine, two-seat, single-bay biplane scout.
   Manufacturer: The British & Colonial Aeroplane Co Ltd, Filton, Bristol.
Powerplant: One 110hp Clerget engine; also 100hp Gnome monosoupape engine.
   Dimensions: Span, 28ft 2in; length, 21ft 3in; height, 10ft 0in.
   Weights: All-up, 1,400lb.
   Performance: Max speed, 95 mph at sea level; endurance, 3 hr.
   Armament: Probably a single Lewis machine gun mounted above the wing centre section.
   Prototypes: Two, Nos 7836 and 7837 (first flown in May 1916). No production.

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

BRISTOL S.2A UK

   A derivative of the Scout D intended to meet an Admiralty specification for a two-seat fighter, the S.2A had side-by-side seating and was intended to be armed with a single 0.303-in (7,7-mm) Lewis gun. In the event, it was rejected by the Admiralty in favour of the Sopwith 1 1/2 Strutter, but work continued on the two prototypes at the behest of the War Office which envisaged the type primarily as a potential advanced trainer for the RFC. The two prototypes were completed in May and June 1916 respectively, being powered by the 110 hp Clerget engine (although one was later re-engined with a 100 hp Gnome Monosoupape), and were delivered to the Central Flying School at Upavon. They were found to be manoeuvrable and quite fast, but no further development was undertaken.

Max speed, 95mph (153 km/h).
Endurance, 3.0 hrs.
Loaded weight, 1,400 lb (635 kg). Span, 28 ft 2 in (8,58m).
Length, 21 ft 3 in (6,48 m).
Height, 10 ft 0 in (3.05 m).

J.Bruce British Aeroplanes 1914-1918 (Putnam)

Bristol S.2A

  THE lack of a British synchronising gear for machine-guns resulted in the appearance of some peculiar aeroplanes in the early stages of the war. Usually the compromise which had to be adopted in order to provide reasonably effective armament had a catastrophic effect upon performance.
  The Bristol S.2A was a reasoned attempt to produce a two-seat scouting aeroplane with the speed of a single-seater but capable of defending itself while yet remaining under the full control of its pilot. The aeroplane was a small side-by-side two-seater biplane; the passenger was responsible for firing the defensive armament.
  The machine was a development of the Scout D. In fact, it had the same wings and tail-unit as the single-seater. The fuselage was wide enough to accommodate the two occupants side-by-side, and the centre-section was correspondingly wider than that of the Scout D. The engine was the 110 h.p. Clerget, which proved to be somewhat troublesome.
  Two prototypes were built in May and June, 1916, and the type proved to be quite fast and manoeuvrable under test. Production was not undertaken, for interrupter gears had meanwhile become available.
  One of the S.2As was later used at Gosport, where it was fitted with a 100 h.p. Gnome Monosoupape and was flown with a modified engine cowling. There was no cowling below the level of the airscrew shaft, and three large apertures were cut in the upper portion.


SPECIFICATION
  Manufacturers: The British & Colonial Aeroplane Co., Ltd., Filton and Brislington, Bristol.
  Power: 110 h.p. Clerget; 100 h.p. Gnome Monosoupape.
  Dimensions: Span: 28 ft 2 in. Length: 21 ft 3 in. Height: 10 ft. Chord: 4 ft 6 in. Span of tail: 10 ft.
  Weights: Loaded: 1,400 lb.
  Performance: Maximum speed: 95 m.p.h.
  Production: Two prototypes were built under Contract No. 87/A/372.
  Serial Numbers: 7836-7837.

H.King Armament of British Aircraft (Putnam)

S.2A. This 1916 development of the Scout, designed for the Admiralty, had side-by-side seating and was intended for fighting. The proposed armament was a Lewis gun, possibly on a pillar mounting behind the cockpit.