A.Jackson De Havilland Aircraft since 1909 (Putnam)

Royal Aircraft Factory B.S.1

  The last aircraft designed by Geoffrey de Havilland and his team before he left to join the Aircraft Manufacturing Co. Ltd. was the B.S.1 single seat biplane flown early in 1913. Powered by a 14 cylinder, two row Gnome rotary, it was the first aeroplane in the world specifically designed as a fast single seat scout and as Bleriot was said to have originated the tractor biplane, was known as the Bleriot Scout, or B.S.1.
  Its wooden, circular section monococque fuselage, a masterpiece of the cabinet maker's art and years ahead of its time, merged smoothly into the lines of the closely cowled engine to give the B.S.1 a very good streamlined shape. Lateral control was by warping the single bay wings and the tail unit featured a diminutive rudder, without fixed fin, mounted above a one-piece tailplane and elevator.
  For its day the B.S.1 was very fast and in March 1913 its designer, now Lt. de Havilland, Special Reserve, was timed over the speed course at 91.4 m.p.h. Unfortunately the rudder was far too small for the considerable keel surface of the deep front fuselage and directional control was poor. Consequently, later on the day of the speed trials, it went out of control in a turn and de Havilland was injured as it struck the ground in a flat spin.
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SPECIFICATION AND DATA
  Construction: By the Royal Aircraft Factory, Farnborough, Hants.
  Power Plants:
   (B.S.1) One 100 h.p. Gnome
  Dimensions: Span 27 ft. 6 in. Length 22 ft. 0 in.
  Weights: All-up weight 1,230 lb.
  Performance:
   (B.S.1)
   Maximum speed 92 m.p.h. Landing speed 51 m.p.h.
   Initial climb 900 ft. min. Endurance 3 hours

P.Hare Royal Aircraft Factory (Putnam)

B.S.1

  The design of this, the world's first single-seater scout, was undertaken by Geoffrey de Havilland, with assistance from Henry Folland and S J Waters. Its basic layout was scaled down from the B.E.3, though it had single-bay wings, an early use of such a bracing system. Lateral control was by warping. The streamlined fuselage was of circular cross-section, and the front section was built around four longerons which extended only from the engine mounting plate to a point some three feet aft of the cockpit. The rear fuselage was of true monocoque construction. Although the engine cowling allowed sufficient space for the 140hp two-row Gnome rotary which de Havilland considered might prove necessary to attain the desired speed, a smaller Gnome, rated at 100hp, was fitted initially.
  Immediately behind the engine mounting plate was a divided tank holding twenty-two gallons of petrol and eleven gallons of oil, thus placing the disposable load on the centre of gravity. There was no instrument panel as such, the few instruments fitted - revolution counter, altimeter, airspeed indicator, watch and compass - being attached directly to the rear face of the fuel tank. The sturdy twin-skid undercarriage, which was typical of the period, was less aesthetically pleasing than the rest of the otherwise advanced design, although the wheel spokes were fabric covered to reduce drag.
  The 'Bleriot Scout' was completed early in 1913 and was test-flown by de Havilland on 13 March. Its maximum speed was in excess of 90mph, and its initial rate of climb was around 800ft/min. Control was light, but de Havilland thought that the rudder was too small, as a result of the scaling down from the B.E.3, especially as the covered wheels added keel area forward of the centre of gravity. By 25 March he had designed a larger rudder, but continued to fly the aeroplane with the original unit while waiting for the replacement.
  Unfortunately, at about 5.00pm on 27 March, de Havilland went into a spin in the B.S.1 while turning at a height of about 100ft, proving his diagnosis regarding the rudder to have been correct, and crashed to the ground. His injuries, according to O'Gorman's report, were confined to 'two badly strained ankles and the loss of some teeth', but in fact he had also fractured his jaw. The report, which was intended for submission to the War Office, was probably composed to make as light as possible of the affair, and refers to the machine ' . . . smashing first the skids and then the bodywork', but as O'Gorman estimated the cost of repairs at ?900 the damage was clearly much more serious than the description suggests.
  Authority for the repair was eventually granted, and upon completion the aeroplane became known as the S.E.2 ('S' now standing for 'Scouting'). There is some evidence to suggest that it had already been thus redesignated at the time of its crash, and its continued career is described under that designation.

  Powerplant: 100hp Gnome rotary
  Dimensions:
   span 27ft 6in
   length 20ft 6in;
   height 8ft 10in.
  Weight: 1,232lb (loaded).
  Performance:
   max speed 92mph at sea level;
   min speed 51mph;
   initial climb 800ft/min (approx).


B.S.2

  Few details are known of this machine, except that it was to have been rather larger than its predecessor, with a welded-steel-tube fuselage. It has been suggested that it may have formed the basis for the design of the R.E.1.

  No dimensions known.

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

P.Lewis British Aircraft 1809-1914 (Putnam)

S.E.2/S.E.2a/B.S.1/B.S.2

  During 1912 the Royal Aircraft Factory at Farnborough drew up plans of its own conception of a single-seat scouting biplane, the first example anywhere of such a type. Designed by Geoffrey de Havilland, it was designated B.S.I and was built early in 1913. Originally the scheduled power plant was a fourteen-cylinder two-row 140 h.p. Gnome, but when the machine appeared it was fitted with a ten-cylinder two-row 100 h.p. Gnome. The experience gained by the Factory with the B.E.I and the S.E.I was used to produce a single-bay staggered biplane of advanced aerodynamic practice and with a fine, streamlined appearance.
  The fuselage consisted of a circular wooden monocoque shell into which the engine was faired with a close-fitting cowling. External bracing was by streamlined Raf-wires. No fin was fitted, the tail unit being similar in shape to that used on the B.E.3; the elevator was in one piece.
  The B.S.I was tested by Lt. de Havilland in March, 1913, and crashed after a fast, measured-course run at 91.4 m.p.h., the pilot sustaining a broken jaw. A speed range of 51-92 m.p.h. had been established during the tests. The cause of the crash was attributed to incorrect balance of side areas, an aspect of design about which comparatively little was known at the time, the machine going into a slow flat spin.
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SPECIFICATION

  Description: Single-seat tractor biplane scout. Wooden structure, fabric covered.
  Manufacturers: Royal Aircraft Factory, Farnborough, Hants.
  Power Plant: 100 h.p. Gnome.
  Dimensions: Span, 27 ft. 6 ins. Length, 22 ft.
  Weights: Loaded, 1,232 lb.
  Performance: Maximum speed, 92 m.p.h. Landing speed, 51 m.p.h. Climb, 900 ft./min. Endurance, 3 hrs.

P.Lewis The British Fighter since 1912 (Putnam)

Meanwhile, the Royal Aircraft Factory had been extremely fortunate in attracting to its staff some of the best brains in the new science. The scope of technical investigation had increased steadily with the improvement in facilities for research, and sufficient practical experience had been accumulated to enable the staff to undertake the design and construction of a small but, for the era, remarkably advanced series of scouts.
  The first outcome of this new line of investigation was the B.S.1, designed by Geoffrey de Havilland during 1912 and completed early in 1913. Considering that the machine was drawn up such a short time after consistent and reasonably reliable flying had become commonplace in Britain, it was an extraordinary and brilliant example of swift progress and advanced applied aerodynamics. Gone was the simple rectangular-section fuselage which had so far been the accepted thing. In its place was a finely-contoured, wooden monocoque structure with the engine cleanly blended into the circular section under a neat metal cowling. Originally the fourteen-cylinder, two-row 140 h.p. Gnome was chosen but substituted was the less-powerful ten-cylinder two-row 100 h.p. Gnome. The B.S.1’s elegant form was that of a tractor biplane with well-staggered single-bay wings, this last feature - in company with cutouts at the upper and lower centre-sections - being incorporated to give the pilot the best possible view from his well-shielded cockpit. Streamlined bracing-wires, known as Raf-wires, were Factory developments and were used on the scout. The shape of the wingtips and the tail unit showed that the B.S.1 had its ancestry in the B.E.2 and B.E.3.
  The machine, the first in line of all single-seat scouts, was tested by de Havilland during March, 1913, but, in his hands, crashed in the same month. Before the accident, however, tests revealed an excellent performance, including a top speed of 91’4 m.p.h. over a measured course, a climb of 900 ft./min. and an endurance of 3 hours. The mishap, which gave the pilot a broken jaw, was the result of faulty side area balancing, a part of the art of design which was then still rather a mystery.