The Koolhoven F.K.58 was a single engine, interceptor-fighter designed by Koolhoven under contract by France.

In 1937, as it became apparent to the French Air Council that domestic manufacturers would not be sufficient to equip the Armée de l'Air with enough fighters, the Dutch were contracted to produce a cheap, high performance fighter to supplement French construction. As produced, it was rather better than the M.S.406 and comparable to the Bloch MB.151 and inferior to the D.520 and most of the German aircraft it faced. It was of composite construction like the British Hurricane with a body of wooden and steel tubing and a skin of metal plates and linen. The wings were made entirely of wood.

The prototype F.K.58 first flew on July 17, 1938. The French placed an order for 50 planes in January, 1939, and the Dutch also placed an order for 36 planes based on the performance of the second prototype (the first having been destroyed in a crash). Unfortunately, just seventeen were completed at the Fokker works due to insufficient French-supplied engines and instruments, and they were sent to France fitted with Dutch equipment. Production was transferred to Nevèrs where just one more F.K.58 was produced. The completed planes were fitted with French equipment and their loaner parts returned to Holland.

Even had the order of fifty aircraft been available for the Battle of France, it is unlikely that the small number of aircraft, outclassed as they were by German fighters, could have changed the outcome much. Had they employed in their intended role as colonial fighters, they might have acquitted themselves well against the Italian planes in that theatre.

Operational history

The F.K.58 was originally procured for use as colonial fighters. Instead, the thirteen planes operational by May of 1940 were manned by escaped Polish pilots and used in the defence of French cities.

Variants

• F.K.58 - Prototype equipped with 1080 hp Hispano-Suiza 14AA engine (2 produced)
• F.K.58a - production version (18 produced)

Specifications (F.K.58)

General characteristics

• Crew: one
• Length: 8.7 m (28 ft 6.75 in)
• Wingspan: 11 m (36 ft 1.25 in)
• Height: 3 m (9 ft 10 in)
• Wing area: 17.3 m² (186.2 ft&sup2)
• Empty: 1,930 kg (4,255 lb)
• Loaded: 2,750 kg (6,063 lb)
• Maximum takeoff:
• Powerplant: 1 x Gnome-Rhône 14N 39,769 kW (1,030 hp)

Performance

• Maximum speed: 475 km/h (295 mph)
• Cruising speed: 430km/h (267 mph)
• Range: 750 km (466 miles)
• Service ceiling: 10,000 m (32,810 ft)
• Rate of climb: 694 m/min (1,130 ft/min)
• Wing loading: kg/m² ( lb/ft²)
• Power/Mass: kW/kg ( hp/lb)

Armament

• 4x 7.9 mm 7.9 mm FN-Browning machine guns in underwing fairings

Related content

Related development:

Comparable aircraft:

Designation sequence:

See also:

• List of aircraft of the Armée de l'Air, World War II