Koolhoven F.K.56

The Koolhoven F.K.56 was a 1930s Dutch basic training monoplane designed and built by Koolhoven.

Koolhoven F.K.56
3-views of the F.K.56
Role	Basic training monoplane
National origin	Netherlands
Manufacturer	Koolhoven
First flight	30 June 1938
Primary user	Netherlands Army
Number built	31

Development

The F.K.56 was a low-wing monoplane powered by a 450 hp (336 kW) Wright Whirlwind R-975-E3 radial piston engine. Designed as a basic trainer, the F.K.56 had two seats in tandem for the instructor and pupil under a fully enclosed canopy. The first prototype flew on 30 June 1938 and had fixed conventional landing gear and an inverted gull wing. The second prototype had retractable landing gear while a third prototype was fitted with a straight wing and dual controls.

Ten aircraft were ordered by the Netherlands Army based on the design of the third prototype. These ten, including the re-worked first and third prototypes, were all delivered before the German invasion of the Netherlands in May 1940.

Earlier in February 1940 the Belgians had ordered twenty F.K.56 basic trainers and seven had been delivered before the rest were destroyed in an air raid on the Waalhaven factory.

Operators

Belgium

• Belgian Air Force

Netherlands

Specifications

Data from

General characteristics

• Crew: 2
• Length: 7.85 m (25 ft 9 in)
• Wingspan: 11.50 m (37 ft 9 in)
• Height: 2.30 m (7 ft 7 in)
• Wing area: 20 m² (220 sq ft)
• Empty weight: 1,058 kg (2,332 lb)
• Max takeoff weight: 1,600 kg (3,527 lb)
• Powerplant: 1 × Wright Whirlwind R-975-E3 Radial piston engine, 336 kW (451 hp)

Performance

• Maximum speed: 300 km/h (190 mph, 160 kn) at a height of 500m (1640 ft)
• Range: 800 km (500 mi, 430 nmi)
• Service ceiling: 7,300 m (24,000 ft)

References

Bibliography

• The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.
• Cortet, Pierre (July 2000). "Rétros du Mois" [Retros of the Month]. Avions: Toute l'Aéronautique et son histoire (in French) (88): 4. ISSN 1243-8650.