Designed by Frederik Koolhoven, the F.K.8 prototype first flew in May 1916, and was similar to its predecessor, the F.K.3 and intended to supersede the capabilities of the FK.3.

The standard production versions were powered by a 120 hp Beardmore engine and in the original form had an angular engine cowling and radiators which met in an inverted Vee in front of the top wing. After a time production aircraft were delivered with a more rounded cowling carrying a small box-like radiator on each side.

Early models had a Vee-skid in front of their wheels.

Later machines with a 160 hp Beardmore. All were fitted with a form of dual control so that the rear cockpit observer could partially fly the machine if his pilot was incapacitated.

Armament consisted of a single forward-firing fixed 7.62mm Vickers machine gun and a single 7.62mm trainable Lewis-type in the rear cockpit position. Provisions for bombs were also a part of the arsenal for the FK.8.

The first RFC unit to receive F.K.8s was 35 Squadron, which flew fully equipped to France on January 24, 1917. Number 2 Squadron began to re-equip in April 1917; 10 Squadron in July; 8 Squadron in August, and 82 Squadron, fully equipped with the type, arrived in France in November 1917. In the Middle East zone of operations, 17 and 47 Squadrons in Macedonia, and 142 Squadron in Palestine were equipped with F.K.8s by 1918, and continued to operate them until the end of the war. In England, several home defence units were partly equipped with the F.K.8, and one belonging to 50 Squadron was responsible for shooting down a Gotha bomber on July 7, 1917.

The F.K.8 first came into prominence during the German spring offensive of March 1918, being used primarily in a tactical low-level bombing and strafing role against German infantry.

At least 1596 machines were built and delivered for service use. By October 31, 1918, a total of 694 F.K.8s were still on RAF charge, but at the end of 1919 few examples remained. Eight found their way onto the Civil Register, and two went to Australia where they helped to pioneer air travel from late 1922 onwards.

Gallery

Armstrong Whitworth F.K.8
Engine: 1 x 120hp Beardmore
Wingspan: 13.26 m / 43 ft 6 in
Length: 9.58 m / 31 ft 5 in
Height: 3.33 m / 10 ft 11 in
Wing area: 540 sq.ft
Armament: 1 x 7.62mm Vickers mg, 1 x 7.62mm Lewis mg

Armstrong Whitworth F.K.8
Engine: 1 x 160hp Beardmore
Wingspan: 13.26 m / 43 ft 6 in
Length: 9.58 m / 31 ft 5 in
Height: 3.33 m / 10 ft 11 in
Wing area: 540 sq.ft
Max take-off weight: 1275 kg / 2811 lb
Empty Weight: 1,918 lbs (870kg)
Fuel capacity: 47.5 Imp.Gal
Max. speed: 153 km/h / 95 mph / 83kt
Service ceiling: 3690 m / 12100 ft
Endurance: 3 hr
Armament: 1 x 7.62mm Vickers mg, 1 x 7.62mm Lewis mg
Crew: 2
Hardpoints: 4

When W G Armstrong, Whitworth & Co received a contract in 1914 to build B.E.2 aircraft for the Royal Flying Corps and the Royal New Zealand Air Service, it offered to design and build a simpler but equally efficient two seat trainer aircraft instead. Similar in configuration to the B.E. in its initial state, with separated cockpits for pilot and observer, the Frederik Koolhoven designed F.K.3 construction started in August 1915.

Armstrong Whitworth F.K.3 Article

Production versions incorpo¬rated a tandem crew cockpit with the pilot seated forward and a more efficient tail design. The prototype F.K.3 had a 120 hp Austro Daimler engine, but most production models had the 90 hp RAF la, while a few had the 105 hp RAF lb.

Approximately 500 F.K.3s were ordered for RFC use, the bulk of which were allotted to training units where they gave service until the end of hostilities.

Only one RFC squadron used F.K.3s operationally; 47 Squadron in Macedonia, where they became a bomber and general reconnaissance machine from late 1916 until the Armistice. On October 31, 1918, the RAF had a total of 62 F.K.3s still on charge. At least four of these went onto the post 1918 Civil Register as G-¬EABY (ex 119629), G EABZ (ex-B9518), G EAEU (ex-B9612) and G EALK (ex-B9603).

Engine: RAF.1a, 90 hp or Beardmore, 120 hp
Span: 12.2 m (40 ft)
Length: 8.8 m (29 ft)
Height: 3.6 m (11 ft 10.75 in)
Empty weight: 762 kg / 1682 lb
Loaded weight: 932 kg / 2056 lb
Maximum speed: 142 km/h (88 mph) at 1980 m (6500 ft)
Service ceiling: 3962 m (13 000 ft)