04/15/2018. Remarks by Johan Visschedijk: "When Captain F.M. Green became chief aeronautical engineer of the Siddeley-Deasy Motor Car Company in January 1917, he began the design of a single-seat fighter. A compact single-bay sesquiplane predominantly of wooden construction with fabric skinning, the S.R.2 was powered by a 320 h.p. A.B.C. Dragonfly nine-cylinder radial engine. Armament comprised two synchronized 0.303 in (7.7 mm) machine guns. A contract for six prototypes was reduced to three in mid-1918, the first of these (serialed C4541) flying in April 1919, by which time the fighter had been officially named Siskin. The first prototype Siskin was subsequently re-engined with one of the earliest two-row radials, the 325 h.p. fourteen-cylinder Armstrong Siddeley Jaguar. Development in this form was continued by the Armstrong Whitworth.company.

In 1921 Siddeley Deasy acquired the name and goodwill of Sir W.G. Armstrong Whitworth & Co. Ltd, which had closed down its aviation department. Retaining the basic features of its predecessor, the Siskin Mk.II evolved in 1922. This was completely redesigned structurally, and embodied fuselage and wing spars of high-tensile steel tubing and strip. Registered G-EBEU on August 21, 1922, the two-seater Siskin Mk.II was powered by the 325 h.p. Jaguar I. It participated in the very first King's Cup Race, which started at Croydon on September 8, 1922. It averaged 127 mph (204 kmh) on the round Britain course until a broken center section fitting compelled test pilot Frank T. Courtney to land it at Manchester.

G-EBEU was again entered in the King's Cup Race in July 1923, this time modified as a single-seater with an increase in performance sufficient to give Courtney a handsome win at an average speed of 149 mph (240 kmh). G-EBEU was also shown abroad and in December 1924 was exhibited in Czechoslovakia at the Prague Aero Show. On August 11, 1925, the aircraft was deregistered as permanently withdrawn from use.

Meanwhile a second Siskin Mk.II had been completed as a single-seat fighter constructed, this was registered G-EBHY (c/n A.W.11) on October 1, 1923, to enable it to fly over foreign soil en route to demonstrations in all quarters of Europe. However, the Siskin Mk.II failed to attract orders. G-EBHY was deregistered on September 2, 1925, and fitted with skis it was sold to the Royal Swedish AF."