Marinens Flyvebaatfabrikk M.F.9

The Marinens Flyvebaatfabrikk M.F.9 Høverjager ("Høver fighter"), also known as the Høver M.F.9 after its designer, was a fighter seaplane built in Norway in the 1920s.

Marinens Flyvebaatfabrikk M.F.9
Class Aircraft
Type Fighter
Manufacturer Marinens Flyvebaatfabrikk
Origin Norway
Country Name Origin Year
Norway 1925
Country Name Operational Year Retirement Year
Norway View
ManufacturerName Production From Production To Quantity
Marinens Flyvebaatfabrikk 10 View

It was a largely conventional single-bay biplane design, but featured an additional set of struts bracing the lower wings to the fuselage sides. An open cockpit was provided for the pilot and construction throughout was of wood. Performance was impressive, with the type setting a European altitude record of 8,600 m (28,200 ft) in 1931 but it was never a popular aircraft with pilots on account of its tendency to spin.

The prototype first flew on 4 June 1925 and completed four trips on the first day with very satisfying results. The next day speed and altitude tests were held, again with good results. Testing was then unexpectedly halted as the testing officer, Lützow-Holm, was ordered to Svalbard to take part in the search for the missing polar explorer Roald Amundsen and his two Dornier Wal flying boats.

The prototype, F.120, was used as a target aircraft during anti-aircraft artillery demonstrations on 13 September 1925, fitted with skis in February–March 1926 and was handed over for active service on 15 July 1926. F.120 exceeded all expectations as to speed, rate of climb and maximum altitude, leading the way for the manufacture of the remaining three aircraft on order from July 1925. Having been slightly modified from the prototype, the three other aircraft were designated as M.F.9Bs (F.122, F.124 and F.126). At first the M.F.9s received an enthusiastic welcome in the RNNAS, but after a near-fatal spin accident due to a structural breakage in the engine in September 1926 confidence in the aircraft type began to wane.

Role Fighter seaplane
National origin Norway
Manufacturer Marinens Flyvebaatfabrikk
Designer Johann E. Høver
First flight 4 June 1925
Retired 17 July 1932
Primary user Royal Norwegian Navy Air Service
Number built 10

General characteristics

  • Crew: One pilot
  • Length: 7.77 m (25 ft 6 in)
  • Wingspan: 10.45 m (34 ft 3 in)
  • Height: 3,12 m (10 ft 3 in)
  • Wing area: 28.0 m2 (301 ft2)
  • Empty weight: 970 kg (2134 lb)
  • Gross weight: 1,380 kg (3036 lb)
  • Powerplant: 1 × 300 hp eight-cylinder Hispano-Suiza, 224 kW (300 hp)


  • Maximum speed: 200 km/h (125 mph)
  • Cruising speed: 150 km/h (95 mph)
  • Range: 550 km (345 miles)
  • Rate of climb: 5.55 m/s (1092 ft/min)


  • 1 × fixed, forward-firing Vickers machine gun or Colt machine gun

End notes