Military Wiki
Role Reconnaissance-fighter
Manufacturer Nationale Vliegtuig Industrie
First flight June 1923
Introduction 1925
Retired 1927
Primary user Finnish Air Force
Number built 17

NVI F.K.31 was a Dutch designed, two seat reconnaissance-fighter, which was developed in the 1920s by Frederick Koolhoven. The aircraft was equipped with an enclosed cockpit and single-strut landing gear. Only a small number of aircraft were produced. The aircraft saw some service in the Finnish Air Force.


The F.K.31 became Koolhoven's first design for the N.V. Nationale Vliegtuig Industrie ("National Aircraft Industry") a two seat scout and fighter. Its prototype became the sensation of the Paris Air Salon of 1922. However, the production of the F.K.31 met with many difficulties, forcing the N.V. Nationale Vliegtuig Industrie to close down.

Use in Finland[]

The Finnish Air Force used twelve F.K.31s between 1925-27. The aircraft had been purchased while the development still was being carried out. The Finnish pilots disliked the aircraft and it has been considered the worst aircraft of the FAF. The F.K.31s flew for fewer than 6 hours in the Finnish Air Force.



Specifications (F.K.31)[]

Data from {KOOLHOVEN FK 31}[1]

General characteristics

  • Crew: One, pilot
  • Length: 7.80 m (25 ft 7 in)
  • Wingspan: 13.75 m (45 ft 1 in)
  • Height: 3.40 m (11 ft 2 in)
  • Wing area: 27.20 m² (292.7 ft²)
  • Empty weight: 1,050 kg (2,310 lb)
  • Max. takeoff weight: 1,800 kg (3,960 lb)
  • Powerplant: 1 × Bristol Jupiter IV 9-cylinder radial engine, 313 kW (420 hp)


  • Maximum speed: 235 km/h (126 knots, 145 mph)
  • Service ceiling: 7,200 m (23,616 ft)
  • Endurance: 6 hours


  • 2 × 7.7 mm machine guns
  • References[]

    1. {{Unreferenced cite web |url= |title=KOOLHOVEN FK 31 |last= |first= |date= |accessdate=2007-01-19 |work= |publisher= }}
    • Green, William; Gordon Swanborough (1994). The Complete Book of Fighters. New York: Smithmark. ISBN 0-8317-3939-8. 

    This page uses Creative Commons Licensed content from Wikipedia (view authors).