Fokker C.X [C.10]
Introduction
The Fokker C-X was - together with the C-V - the only prominent bi-plane in the WWII fleet of the Dutch airforce. The C-X - although outdated - performed surprisingly well as a light strike plane.
Design and construction
Late 1933 the design of a new airforce reconnaissance plane [as a replacement of the C.V] was started, which was followed by the first [prototype] flight in October 1934. The C.X resembled the features of its pre-ancestor but was more aerodynamic and a tiny bit smaller.
Although its design was started on instigation of the NEI [Netherlands East-Indies] airforce, the first order for a production series was received from the Netherlands airforce. It was a trial order for 4 C.X's, in 1936 followed by another order for 16 more. All 20 planes were registered in the 700-series [700 u/I 719].
The C.X was designated as a strategic [medium range] reconnaissance plane with ground support capabilities. In order to meet the latter it was imperative that bomb-racks for different ordinance-configurations could be installed.
Although the C.X was experienced as a satisfying aeroplane to fly, repeated engine problems were experienced. The C.X was equipped with the 640 hp Rolls Royce Kestrel V engine. Just like the similar engines of the C.V this engine had a fabrication weakness in respect to its gear-wheels. These had to be replaced every so many hours due to extreme wear. Also the engine suffered from hampering fuel injection under higher G-force circumstances. Although these problems were not solved - other than by replacing parts - the C.X proved a very capable plane; in particular in the role she would be used for during the May War.
The production of a suitable bomb-rack was another challenge. In 1936 none of the C.X's was fitted with an operable rack, for the Van Heyst design failed to pass the trials time and again. Workable racks would therefore only be installed on all C.X's at end of 1937. These racks were the best the Dutch industry could produce at that time - lacking any development experience with bombers. The C.V and C.X racks would still proof quite unreliable during the May War, when a number of planes would return with a considerable part of the ordinance still stuck to the rack(s). This aspect made the planes not only hard to trim during return-flight but it also posed a considerable danger during landing [with life bombs under the wings].
Communication-wise the C.X's - like the C.V's - were equipped with radio-telegraphs. The mono wing fighters, Douglas 8A-3N's and T.V bombers were equipped with radio-telephonic systems. The crews of these modern planes could communicate amongst each other. This was no option to fighter crews escorting the older C.V and C.X planes and vice versa. Radio telegraphic traffic was therefore directed to the ground station and from there passed on to the modern planes making use of radio-telephonic ground stations. In real life this problem meant that in formation the old habit of hand-signals were maintained and that escort-flights had to select their meeting-points with the C.V and C.X very carefully otherwise both flights would fail to meet each other.
The C.X was armed with one 7.9 mm FN synchronized machinegun for frontal defence, and a manually operated 7.9 mm Lewis gun in the rear that was operated by the observer/navigator. The plane was capable of carrying 400 kg of bombs; either 8 x 25 kg, 8 x 50 kg or 4 x 100 kg. The first two configurations were applied during the May War.
The Fokker C.X was fitted with a Rolls Royce Kestrel engine of 640 hp. This engine was almost identical to the engine of the C.V but in combination with the superior aerodynamic model of the C.X it provided for a considerable speed increase. The C.V had a top-speed of 250 km/hr with the 630 hp Kestrel engine, whilst the 10 hp more of the C.X engine in combination with the more efficient aerodynamic shape provided for a top speed of 316 km/hr. Cruising speed was about 270 km/hr. Also the ceiling of the C.X [8,300 m - 27,500 feet] was much higher in comparison to the C.V [6,500 m - 22,000 feet]. Climbing speed however was considerably lower than the highly manoeuvrable C.V. The latter was mainly caused by the smaller wing-surface and span of the C.X as well as its heavier airframe weight.
May war
During the May War only 11 [out of 16] C.X's were operational [700, 705, 706, 708, 709, 711 u/I 715, 719], of which 2 [708, 709] were lost due to enemy fighters. The majority of the C.X's were stationed at Bergen AFB, where they were parked outside the base when war broke out. This saved them from destruction when Bergen was taken by surprise by the German Luftwaffe at the first invasion hour.
The C.X's were almost entirely used for ground-attack missions. They raided against the German airborne positions at the AFB's Waalhaven and Valkenburg, at Moerdijk, in and around Rotterdam and against German artillery positions east of the Grebbeberg. These missions were all successfully executed. A limited number of recce missions were flown by individual planes. Two planes [700, 705] flew to France before the capitulation. There they were left [the 700 at Caen; the 705 at Mardyck near Dunkirk], and some crew members managed to evacuate to England.
The Germans captured a number of Fokker C.X's. It is not known what they did with these planes. Possibly they were donated to the Finish airforce.
Service elsewhere
NEI airforce: The NEI airforce bought 13 C.X's in 1936, which were already considered too old to be assigned to operational units when they arrived in the East-Indies. They were all assigned to the flying school at Kalidjati. These planes were not used during the period December 1941-March 1942 when the NEI were in war with Japan. The fate of the planes is uncertain.
Finland: Fokker delivered 4 C.X's to Finland in 1937. These planes were fitted with the 835 hp Bristol Pegasus [radial] engines. The Fins [Valtion Lentokonetehdas] built 30 C.X in license in 1937 and 1938. In 1942 another 5 were produced. Registrations in the Finnish airforce were FK-78 u/i FK-116. These planes flew numerous missions in the Finnish-Russo wars. The remaining C.X's were used until 1958 [!] as training planes.
Spain: In 1936 Spain bought one C.X and later built another one on a license contract. They were used by the Republicans. Their fate is unknown.
Typicals C.X in service with the Dutch airforce May 1940
| Type: | Strategic reconnaissance / light ground support | |
| Manufacturer: | Fokker [Netherlands] | |
| Crew: | 2 [pilot and observer/navigator] | |
| Engine: | Rolls Royce Kestrel V, 640 hp | |
| Armament: | 1 off 7.9 mm FN synchronized frontal machinegun 1 off 7.9 mm Lewis manually operated machinegun rear 400 kg bombs [8 x 25 kg; 8 x 50 kg; 4 x 100 kg] |
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| Size: | Length: 8,8 m Wing span: 12 m |
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| Weight: | 2,300 kg [full tank and ammo, no ordinance] | |
| Max. speed: | 316 km/hr [cruising speed 270 km/hr] | |
| Range: | 830 km | |
| Ceiling: | 8,300 m [27,500 feet] | |
| In service: | 1935-1940 | |
| In service May 1940: | 16 [of which 11 operational and 5 in repair at 10 May] | |
