The manufacturing firm W.G. Armstrong, Whitworth & Co, Ltd. of Newcastle-on-Tyne hired Dutch designer Frederick Koolhoven as their chief designer,. This led to a pair of robust, underappreciated two-seater F.K. aeroplane designs. The aircraft division of the company did not last long after the war, closing in late 1919.
Aircraft from the Great War or shortly thereafter include:
- The FK1 was a prototype 1914 biplane.
- The FK10 was a quadriplane two-seater. Four prototypes were built in 1917, but it was not selected for production.
- As if four wings were not enough, the FK11 took an FK10 fuselage and mounted fifteen narrow-chord staggered wings.
- The FK12 was an awkward-looking triplane multiseat escort that was abandoned due to performance problems.
- The FM4 was a bulky prototype single-seat fighter from autumn 1918 that was not produced.
- The Ara was an elegant fighter that did not fly until 1919. It was doomed by the failure of the A.B.C. Dragonfly radial engine.
- Bruce'69, p.10.
- Bruce'69, p.29.
- Bruce'69, pp.21-24.
- Bruce'69, p.24.
- Bruce'69, pp.25-26.
- Bruce'69, pp.26-28.
- Bruce'69, pp.28-29.