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Koolhoven F.K.55

Netherlands (1938)
Picture of Koolhoven F.K.55 Single-Seat, Single-Engine Prototype Fighter Aircraft

Only one example of the Dutch Koolhoven F.K.55 fighter was ever completed before the program was cancelled in full prior to World War 2.


Detailing the development and operational history of the Koolhoven F.K.55 Single-Seat, Single-Engine Prototype Fighter Aircraft.  Entry last updated on 5/10/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com

Prior to World War 2 (1939-1945) the Dutch held a respectable aero industry that produced a few notable types of local design. The Koolhoven F.K.55 was a prototype developed along the lines of a high-speed fighter and appeared during the latter half of the 1930s. The line ended with a sole example being built, its first flight held on June 30th, 1938, and the program terminated before the end of the year.

Its design, begun in 1937, was one of a sleek all-modern fighter with the cockpit set forward of the wing mainplanes and the mainplanes shifted just ahead of midships (and shoulder-mounted). Wingtips were rounded and the appendages straight in appearance. The tail unit was conventional with a single fin and a pair of horizontal planes. Construction was mixed, composed of metal and wood. A "tail dragger" undercarriage was featured. The engine of choice became a Lorraine 12Hrs "Petrel" V-12 of 860 horsepower driving a pair of two-bladed propeller assemblies at the nose in contra-rotating fashion. Due to the placement of the cockpit, well forward in the fuselage, the engine was installed aft of the pilot (as in the famous Bell P-39 "AiraCobra" fighter detailed elsewhere on this site).

The completed aircraft was made ready for its first flight in the early part of 1938 and has all of the appearance required of a high-performance aircraft. A fixed undercarriage greeted this monumental moment for the design with the intention that a retractable system be instituted later in development. However, in practice, the design proved lacking in the power necessary for the role - the 860 horsepower produced for the engine was just take-off power. Underpowered and costly to revise, this aircraft endeavor was eventually abandoned by Koolhoven and fell to the pages of military aviation history. Engineers pushed for the installation of a Lorraine "Sterna" supercharged engine of 1,200 horsepower to no avail.

As designed, the F.K.55 sported an maximum speed of 317 miles per hour, a cruising speed nearing 280 miles per hour, a range out to 530 miles and a rate-of-climb of 2,580 feet-per-minute (all figures estimated by Koolhoven). Its proposed armament scheme was to fit a 20mm cannon firing through the propeller hub and 4 x .303 machines guns, two installed in each wing. The P-39 fielded similar armament though a more potent 37mm autocannon in the nose. Its performance was much better as well: a maximum speed of 375 mph was seen in the Q-models. Like the F.K.55, it first flew in 1938 and went on to have a strong war record in the subsequent global conflict.

Any available statistics for the Koolhoven F.K.55 Single-Seat, Single-Engine Prototype Fighter Aircraft are showcased in the areas immediately below. Categories include basic specifications covering country-of-origin, operational status, manufacture(s) and total quantitative production. Other qualities showcased are related to structural values (namely dimensions), installed power and standard day performance figures, installed or proposed armament and mission equipment (if any), global users (from A-to-Z) and series model variants (if any).






Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed Rating
Hi: 400mph
Lo: 200mph
    This entry's maximum listed speed (317mph).

    Graph average of 300 miles-per-hour.
City-to-City Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
BER
 
  MOS
MOS
 
  TOK
TOK
 
  SYD
SYD
 
  LAX
LAX
 
  NYC
Graph showcases the Koolhoven F.K.55's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
1
1


  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


  Compare this entry against other aircraft using our Comparison Tool  
National Flag Graphic
Origin: Netherlands
Year: 1938
Type: Single-Seat, Single-Engine Prototype Fighter Aircraft
Manufacturer(s): Koolhoven - Netherlands
Production: 1
Status: Cancelled
Global Operators:
Netherlands (cancelled)
Historical Commitments / Honors:

Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Koolhoven F.K.55 model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
1


Dimension
LENGTH


Feet
30.35 ft


Meters
9.25 m


Dimension
WIDTH


Feet
31.50 ft


Meters
9.6 m


Dimension
HEIGHT


Feet
8.53 ft


Meters
2.6 m


Weight
EMPTY


Pounds
3,527 lb


Kilograms
1,600 kg


Weight
LOADED


Pounds
4,850 lb


Kilograms
2,200 kg

Engine icon
Installed Power - Standard Day Performance:
1 x Lorraine Petrel 12Hrs 12-cylinder Vee engine developing 860 horsepower.

Performance
SPEED


Miles-per-Hour
317 mph


Kilometers-per-Hour
510 kph


Knots
275 kts


Performance
RANGE


Miles
528 mi


Kilometers
850 km


Nautical Miles
459 nm


Performance
CLIMB RATE


Feet-per-Minute
2,580 ft/min


Meters-per-Minute
786 m/min

Supported Weapon Systems:

Graphical image of an aircraft medium machine gun
Graphical image of an aircrat automatic cannon
Armament - Hardpoints (0):

PROPOSED:
1 x 20mm cannon firing through propeller hub
4 x 7.7mm (0.303) machine guns in wings
Variants: Series Model Variants
• F.K.55 - Base Series Designation; single prototype completed in 1938.