Armstrong Whitworth
FK 5 and FK 6
During World War One, before the pattern of fast, furious aerial dogfights developed, many in England were proponents of a kind of 'flying battleship'. These people saw more merit in great number of weapons and firepower than speed and maneuverability. The result of this train of thought, which may have come from England's deep-rooted maritime tradition, was a number of big, heavy fighters being built, which did not advance to more than one prototype each.
These big fighters offered room for a pilot and a number of gunners and generally appeared very strange, like, for instance, the Sopwith L.R.T.Tr three-seat triplane and Vickers F.B.11 three-seat biplane. Without a doubt, the strangest aircraft to emerge from the previously mentioned train of thought was Frits Koolhoven's FK 5 design. The FK 5 was a triplane too, and it featured two middle-wing mounted gondolas, in each of which a gunner could accomodate himself with a machine-gun to do battle with the enemy. To provide the gunners with an optimal field of fire, the gondolas protruded a good length ahead of the propellor, which turned mere centimetres away from the wing's leading edge. The pilot sat behind the wings, because of which he only had a good view... upward.
However, Fairbairn-Crawford, Koolhoven's superior, did not trust the craft one bit and refused to give permission for the first flight. A serious row ensued with Koolhoven, but he pressed on anyway. After some test flights, which, as shown in the accompanying photos, went anything but smoothly - the craft crashed at least two times - the project was put on hold. It was only resumed when the English ministry of war communicated its desire for a multiplace escort fighter, which could also serve to tackle the Zeppelin airships that regularly bombarded England. The FK 5 design was altered in such manner so it could perform these tasks. The aircraft that now emerged, designated FK 6, was bigger than the FK 5. The engine and propellor were positioned further away from the wings; the pilot, again seated behind the wings, had a slightly better view - but stellar it still was not. It is possible the two machine-gun gondolas, now mounted below the middle wing, were designed for the Davis gun. Armstrong Whitworth had in fact, in April 1916, received two wooden models of this gun, one for 2 pounds shells, one for 6 pounds shells, in order to, according to official documents, 'equip a large aeroplane, now building for the ministry of war'. This aeroplane can only have been the FK 6. The 23rd of March, 1916, four FK 6 aircraft were ordered, which were to receive serial numbers 7838 through 7841. The numbers 3684 and 3685 were also mentioned in connection with the FK 6, these were to apply to two aircraft for the Royal Naval Air Service. Unfortunately, it is not known whether this concerned two of the four aircraft already ordered, or two additional aircraft. The two aircraft were expected by the RNAS in March 1916, but after November of that year the numbers are no longer mentioned in any publication. It is well possible this is connected to the fact that, around that time, it had become clear that the big, heavy fighter had shown itself to be a mistake and therefore only one FK 6 had been built, the '7838'. Not much is known about the aircraft's test flights, conducted by Lieutenants Peter Legh - who would follow Koolhoven to British Aerial Transport Ltd. and fatally crashed the BAT FK 25 'Basilisk' - and R. Payze. It appears the tests were conducted in slapdash fashion.
During the few flights made, it became readily apparent performance anything but met expectations. Interest in the aircraft had evaporated anyway - the competing Vickers and Sopwith aircraft met the same fate - and development was soon abandoned, which also had to do with the new availability of synchronising gear for machine-guns, which enabled shooting through the propellor-disk.
Technical data FK 6
engine type: 250hp Rolls-Royce
max. speed: 160 km/h (estimated)
take-off weight: unknown
span: 18.90m
length: 11.29m