Nederlandse Modelbouw en Luchtvaartsite

Dutch Modelling and Aviation

In Memoriam

Klaas Willem Jonker
(Wilko)
† April 30, 2018

On Monday 30 April 2018, Wilko Jonker died after a long illness at the age of 58. He leaves behind a wife and two children. The Dutch military aviation and plastic modeling were his hobby and on this website he shared all the knowledge he has collected over the years. His hobby has been able to distract him from the persistent disease in his body until the last week of his life. The contacts with other hobbyists were a major support for him.

This website will be maintained by different people for as long as possible, so that other enthusiasts can continue to benefit from extensive content.

Koolhoven FK.51

In service with LVA; RNlNAS and NEIAF.

In service with LVA.

The first series of ten aircraft was intended as a training aircraft for advanced pilot training. They received the registration 1 to 10 and were, different from the conventional, light blue Colour scheme of the training aircraft of the LVA, overall dark brown. These aircraft looked very similar to the prototype, but they had a more powerful engine.

The second series of registrations 11 to 25 was painted entirely blue.

The third and last series, referred to as a light scouts, registration with 400 to 428 was sprayed overall dark brown.

Soon these aircraft proved not useful for operational reconnaissance purposes and were mainly used for training.

During the armistice in May 1940 the trainers were stationed at Soesterberg and Haamstede. A part of the flight school was moved to Haamstede during the mobilization.

IMG 5938 V2

Koolhoven FK.51 (replica) 429, photographed in 2010 at the Military Aviation Museum at Soesterberg.

IMG 5939

Koolhoven FK.51 (replica) 429, photographed in 2010 at the Military Aviation Museum at Soesterberg.

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IMG 5941 V2

Koolhoven FK.51 (replica) 429, photographed in 2010 at the Military Aviation Museum at Soesterberg.

The scouts were placed with 2LvR and divided into four groups.

These groups were stationed as follows; 1st reconnaissance group, I./2 LvR was stationed with four aircraft at Hilversum; II./2LvR was stationed at Ypenburg with five FK.51s ; III./2LvR was based at Ruigenhoek with four aircraft and finally IV./2LvR was stationed at Gilze-Rijen with five aircraft.

During the war days they were not used for reconnaissance.

On May 10, 1940 one FK.51 was lost at Hilversum during the attack in the early morning, two other FK.51s were damaged. The same day the remaining aircraft were evacuated to Middenmeer and later flown to Ruigenhoek.

The remaining aircraft were destroyed there after the capitulation.

During attacks KF-51 421 was damaged was at Gilze-Rijen. The group IV./LvR was instructed to evacuate to Haamstede; The 415 was not flyable so only 411 left with two Fokker C.V to Haamstede and shortly thereafter shot to fire.

 

Koolhoven FK.51, Serial  8.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Row Koolhoven FK.51s of the first series.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, serial 4 standing near a hangar.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, serial 10.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, serial 1.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 in a hangar at Soesterberg.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, serial 5.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]

 

Koolhoven FK.51, serial 20.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, 22, standing on its nose near Rijswijk, August 2, 1938.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, 18.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, 23, 1st lt G.W. de Zwaan standing in front of it.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 left side view.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Rear view of Koolhoven FK.51.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 11 atp Soesterberg after an accident on May 5, 1939. The aviator was sgt. Ruiter.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 23 with orange triangles.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Accident with Koolhoven FK.51 11 at Soesterberg op May 5, 1939.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 on its nose near Zeist), March 30, 1938.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]

 

Koolhoven FK.51 400 at the Koolhoven factory at Waalhaven.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]

 

Formation of two Koolhoven FK.51's; FK.51 405 in use as weather plane.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Emergency landing at Voorhout by Koolhoven FK.51 428, May 12, 1940; some locals standing on it.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Cockpit Koolhoven FK.51 406 with armament.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 425 with crew.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51 with orange triangle as national markings at Souburg.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Accident with Koolhoven FK.51 11 at Soesterberg May 5, 1939.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Rear armament Koolhoven FK.51 426.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Junkers Ju 52, Henschel Hs 126 and two twee Koolhoven FK.51 after de capitulation on a boat.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]

 

In service with RNlNAS.

In August 1935 the Koolhoven FK.51 was evaluated at naval air station De Kooy Partly under the influence of the order by the LVA, it was decided to order a series of FK.51s to replace the Fokker D.VII and Fokker C.I for the continued flight training.  On August 1, 1936 a first batch of six aircraft was ordered. These were fitted with a Wright Whirlwind R-975-E1 radial engine. The devices could eventually be converted for reconnaissance . On June 18, 1937 a second order for a further nine aircraft followed. The last three of which were delivered as a scout.

The aircraft proved to be very robust, but had a pretty bad view. Reason to doubt the usability as a scout.

After the accident with the E-1 and E-6, in May 1938, research showed that there were cracks in the wooden Astra durabel propellers, so the FK.51s were grounded between May and August 1938. The air screws were replaced with new screws from Aircscrews Ltd.

Until the early spring of 1940, the aircraft were well used for neutrality patrols, but during the May days they were not operational deployed and all were most probably destroyed during air raids on De Kooy.

Advanced trainer Koolhoven FK.51, serial E-12.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Advanced trainer Koolhoven FK.51, serial E-10.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
The only technical officer with a naval fly brevet in the thirties OMSD2 F. ter Horst.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51. Detail Armstrong Siddeley "Cheetah" V9 cylinder radial engine of 325 hp.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Advanced trainer Koolhoven FK.51, serial E-13.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Advanced trainer Koolhoven FK.51, serial E-10.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Advanced trainer Koolhoven FK.51, E3 at air base De Vlijt on the isle of Texel.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]

 

In service with NEIAF.

 The NEIAF ordered between 1935 and 1939 sixty FK.51s spread over four orders. These were to replace the AVRO 504.

The last fifteen aircraft were not delivered due to the German invasion in May 1940. They stood, awaiting the engines at the factory at Waalhaven and and were completely lost during the bombing on may 10, 1940.

The devices were placed at the flying school at Kalidjati.

In September, the aircraft had, just as in the Netherlands, orange triangles applied and later in 1940, a new registration system was implemented, in which the registration of the remaining devices was increased by 100.

De FK.51 was from 1940, gradually replaced by Ryan STM.

At the outbreak of the war on December 7, 1941 were still about twenty aircraft left, which still were used for reconnaissance and for control of the camouflage.

They were assigned to the third and fifth division of the sixth aircraft group, VLG VI. (3-VLG-VI and 5-VLG-VI).

After February 25, 1942, they are no longer operationally deployed. The remaining aircraft that were not destroyed during the bombings, were destroyed on March 8, 1942 at the capitulation.

 
Advanced trainer Koolhoven FK.51, at Kalidjati November 1940, being fuelled.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51. K21, NEIAF at Waalhaven.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, K8, NEIAF.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Koolhoven FK.51, K13, NEIAF.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Tail of Koolhoven FK.51, K26 NEIAF.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]
Advanced trainer Koolhoven FK.51, at Kalidjati, NEIAF 1940.
[Enclosed photo from BeeldBank NIMH. Click on photo for ordering information]