Armstrong Whitworth F.K.6

In 1915, Frederick Koolhoven, the chief designer of Sir W G Armstrong Whitworth & Co Ltd, initiated work on a highly unorthodox three-seat triplane powered by a 250hp Rolls-Royce 12-cylinder water-cooled engine. It was intended to accommodate two gunners each with a 7.7mm machine gun in shallow nacelles mounted above the centre wing on each side of the fuselage, the gunners being seated ahead of the propeller plane of the tractor engine. Although a prototype was completed and allegedly designated F.K.5, this was never flown, being extensively damaged as a result of a ground loop during its first take-off attempt. The design, was extensively revised early in 1916 to meet an RFC requirement for an airship interceptor and long-range escort fighter. The revised design is believed to have been designated F.K.6 (and certainly not F.K.12 as has sometimes been stated) and four examples were ordered, two of these being intended for the RNAS. In the event, only one F.K.6 was built. The gunners' nacelles were underslung on the central mainplane, armament remained two 7.7mm Lewis guns and the 250hp Rolls-Royce engine was retained. It is believed that relatively limited flight testing was undertaken.

FACTS AND FIGURES

© The pilot of the original F.K.6 is unlikely to have been able to see much in any direction. The completely revised second example was only a marginal improvement.

© The nacelles were intended to give the gunners a good field of fire but a better solution might have been a single gunner in the rear fuselage. No armament was actually fitted.

© The middle wing was much longer than the others, but it is hard to know quite why. The other wings were equal span.

3-View

A three-view drawing (1620 x 977)