In April 1916 came the Falcon-virtually a scaled~down Eagle. Again ratings increased and in April 1916 the figure was 205 h.p.; in May, 228 h.p.; in February 1917, 247 h.p.; and in April 1917, 262 h.p, all at 1,800 r.p.m. By November 1917 the output had risen to 278 h.p. and by July 1918 to 285 h.p.-in both instances at 2,000 r.p.m. Official data for the Falcon I were: weight, 650 lb; b.h.p. at normal r.p.m., 228; fuel consumption (gal/hr), 16.6. Corresponding figures for the Falcon II were: 665. 255, 18.25, and for the Falcon III (by far the most famous member of the family) 660, 270, and 18.75.
An unusual feature of this engine is the epicyclic propeller reduction gear which contains a clutch designed to limit the maximum torque, thus protecting the reduction gears.
Constructional particulars for the Eagle VIII apply generally to the Falcon III. First run in 1915, production of the Falcon began in September 1916 and was so successful that it was also manufactured under licence by Brazil Straker in Bristol. Production continued until 1927, by which time 2,185 had been built.
The best-known application of the Falcon was to the Bristol Fighter F.2B, wherein the Series Ill engine became standard and remained in service until the 1930s. Other British military installations were made in the Martinsyde F.1, F.3 and F.4, R.E. 6 and 7, Armstrong Whitworth F.K.12, Avro 523C and 529 Pike, Blackburn S.P. and G.P. seaplanes, Kangaroo and Sprat, D.H.4, Fairey F.2, Sopwith tractor triplane, Parnall Perch, improved Short 184, and Vickers Vendace.
Production ceased in 1927 after 2,185 were built. The unit cost in 1918 was £1,210.
Falcon II (Rolls-Royce 190 hp Mk II)
Falcon III (Rolls-Royce 190 hp Mk III)