J.Bruce British Aeroplanes 1914-1918 (Putnam)

Siddeley Sinaia

  THE design of the Sinaia was begun in the spring of 1918. It was a large twin-engined biplane of distinctive appearance, apparently intended for service as a bomber. In the disposition of its defensive armament the Sinaia struck an original note: the engine nacelles extended rearwards for a considerable distance, and a gunner’s cockpit was provided in the tail of each, quite six feet behind the trailing edges of the wings. Between them these two gunners covered the aircraft’s tail completely; but their positions, full in the slipstreams, must have made it well-nigh impossible for them to wield their Lewis guns.
  A conventional fuselage was used. It terminated in a biplane tail-unit which had a small central fin and three rudders. Both upper and lower elevator surfaces were horn-balanced but did not move in parallel, indicating that one of them was a trimming surface.
  The mainplanes were of unequal chord, and were arranged to fold. Upper and lower ailerons were horn-balanced; the balance areas were similar in shape to the corresponding surfaces on the third Siddeley R.T.1.
  The engines for which the Sinaia was originally designed were two of the new (but now little-known) Siddeley Tigers. The Tiger was a liquid-cooled vee-twelve which developed 486 h.p. With Tiger engines the aircraft was designated Sinaia Mark I. Alternatively, it could be powered by two Rolls-Royce Condors: this was the Sinaia Mk. II. A Mark III version with two Beardmore Atlantics was envisaged, but had been abandoned by January, 1919. It appears that an installation of two Napier Lions was also contemplated.
  Four prototypes were ordered, and the fuselage of the first was in course of assembly late in June, 1918. By that time an experimental forward fuselage portion had been made for tests with a Coventry Ordnance Works quick-firing gun.
  With the Armistice, the need for economy and the absence of any urgency brought work virtually to a standstill; and it was not until June 25th, 1921, that the Sinaia first flew. The test flying was done by Captain Frank T. Courtney. Apparently the aeroplane was not developed, for neither it nor its Tiger engines were later heard of.


SPECIFICATION
  Manufacturers: The Siddeley-Deasy Motor Car Co., Ltd., Park Side, Coventry.
  Power: Sinaia Mk. I: two 486 h.p. Siddeley Tiger. Sinaia Mk. II: two 600 h.p. Rolls-Royce Condor. Sinaia Mk. Ill: two 500 h.p. B.H.P. (Galloway) Atlantic.
  Dimensions: Span: 86 ft 10 in.
  Areas: Wings: 1,823 sq. ft.
  Weights: Loaded: 16,000 lb.
  Armament: Gunners’ cockpits were situated in the nose of the fuselage and at the rear of each engine nacelle, and presumably each would have at least one Lewis machine-gun on a Scarff ring-mounting. Experiments were carried out with a Coventry Ordnance Works quick-firing gun.
  Serial Numbers: J.6858-J.6859.