Marinens Flyvebaatfabrikk M.F.9
Encyclopedia
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.
(RNNAS) began looking for a replacement for its Sopwith Baby
fighter aircraft, contacting 19 foreign manufacturers asking for bids for licence production of four fighter aircraft in Norway. While many offers were received, only a few of the aircraft types on offer were for purpose-designed seaplanes. As it was the clear request of the RNNAS to have a tried and tested seaplane fighter only the bids coming in from Fokker
and Nieuport Astra
satisfied the requirement. As the cost of both these offers were considered far too high, Johann E. Høver, managing director at Marinens Flyvebaatfabrikk
, recommended that a future fighter should be designed and constructed at his factory in Horten
. Høver claimed that he could deliver four fighters with 300 hp Hispano-Suiza
engines at the cost of 220,000 Norwegian krone
r, just half of what the foreign bidders demanded. After cost estimates and calculations had been carried out, the Norwegian Ministry of Defence
approved the project on 8 March 1924. The project was then submitted to the Permanent Flying Commission and evaluated on 1 May 1924. Only Klingenberg, managing director of the Kjeller
Aircraft Factory, had a negative opinion of the design, being especially critical of the choice of a relatively weak engine. The manufacture of parts for the prototype M.F.9 began in August 1924 and the wing construction was tested at an aeronautical institute in Göttingen
in the German Weimar Republic
, as well as being brought to breaking point in Horten. The Royal Norwegian Navy
required the aircraft to have a top speed of 200 km/h, reach an altitude of 3,000 metres in 12 minutes and have a sturdy construction able to endure dog fighting. The aircraft also needed to be a stable platform and be easy to manoeuvre on water.
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.
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.
from the factory in Horten. Although M.F.9s were used during the annual summer exercises only the most experienced officer pilots were allowed to fly the type, all forms of acrobatics being banned and most pilots unwilling to perform any drastic manoeuvres. The first total loss of the type occurred on 27 August 1929 when F.120 crashed during landing. A replacement aircraft, F.120 (II) was finished in June 1930.
As the weak Hispano-Suiza engine prevented the M.F.9 from being a truly effective fighter aircraft work was carried out from the autumn of 1929 to the spring of 1931 to find a different engine to have in reserve and install in case of war. Two engines were tested, first a 425 hp Bristol Jupiter
which at the time was the standard engine of the Norwegian Army Air Service
's Fokker C.V-E
scout-bombers, and secondly an Armstrong Siddeley Jaguar VII 14 cylinder air cooled engine.
However, accidents involving the aircraft entering uncontrolled spins continued with another aircraft being lost on 25 July 1930. At this point pilot confidence in the aircraft reached an all-time low, with seven officer pilots writing a letter of protest to the Ministry of Defence, voicing their opposition to the further use of the M.F.9. The criticism led to the halting of work on five M.F.9s then under construction (F.136, F.138, F.140 and replacement machines F.130 and F.132), although one almost complete M.F.9c (F.142) was finished in February 1932. F.142 and the incomplete aircraft had steel tube hulls instead of the wooden constructions of the earlier aircraft. An investigative commission concluded on 4 May 1932 that even the improved M.F.9c model was not usable for training purposes and recommended that the type should be discarded entirely. Director Høver strongly opposed this view, but did not win through with his view that further improvements could save the aircraft and the type was retired and put in reserve on 17 July 1932. The document sent by the Ministry of Defence to the RNNAS was signed by the Agrarian Party
Minister of Defence
, Vidkun Quisling
.
The reason that the M.F.9 was put in reserve and not scrapped outright was the Sopwith Baby fighters had been scrapped a short time earlier, necessitating the retention of the M.F.9 as a reserve fighter force. Still, by the mid-1930s most of the aircraft were scrapped, the last four being retired in May 1939. The last M.F.9 operational, M.F.9c F.142, was used by the Marinens Flyvebaatfabrikk control officer until 28 May 1937 and then stored at the factory until 6 May 1939 when the Ministry of Defence approved of plans to preserve it as a museum piece. Although the final fate of F.142 is not known, it is assumed that it was burned by the German occupation forces
during the Second World War
. The M.F.9 was never replaced as a fighter in the RNNAS, the service instead choosing to focus on reconnaissance
and torpedo aircraft
.
Background
In the early 1920s the Royal Norwegian Navy Air ServiceRoyal Norwegian Navy Air Service
The Royal Norwegian Navy Air Service was alongside the Norwegian Army Air Service the forerunner to the modern-day Royal Norwegian Air Force.- History :...
(RNNAS) began looking for a replacement for its Sopwith Baby
Sopwith Baby
-See also:...
fighter aircraft, contacting 19 foreign manufacturers asking for bids for licence production of four fighter aircraft in Norway. While many offers were received, only a few of the aircraft types on offer were for purpose-designed seaplanes. As it was the clear request of the RNNAS to have a tried and tested seaplane fighter only the bids coming in from Fokker
Fokker
Fokker was a Dutch aircraft manufacturer named after its founder, Anthony Fokker. The company operated under several different names, starting out in 1912 in Schwerin, Germany, moving to the Netherlands in 1919....
and Nieuport Astra
Nieuport
Nieuport, later Nieuport-Delage, was a French aeroplane company that primarily built racing aircraft before World War I and fighter aircraft during World War I and between the wars.-Beginnings:...
satisfied the requirement. As the cost of both these offers were considered far too high, Johann E. Høver, managing director at Marinens Flyvebaatfabrikk
Marinens Flyvebaatfabrikk
Marinens Flyvebaatfabrikk - The Navy's Flying Boat Factory - was the Royal Norwegian Navy Air Service' aeroplane producer. It was established in Horten in 1915.It produced a total of 120 planes from 1915 to 1940.-Planes produced:...
, recommended that a future fighter should be designed and constructed at his factory in Horten
Horten
is a town and municipality in Vestfold county, Norway—located along the Oslofjord. The administrative centre of the municipality is the town of Horten. The municipality also includes the villages of Borre, Åsgårdstrand, Skoppum, and Nykirke....
. Høver claimed that he could deliver four fighters with 300 hp Hispano-Suiza
Hispano-Suiza
Hispano-Suiza was a Spanish automotive and engineering firm, best known for its luxury cars and aviation engines in the pre-World War II period of the twentieth century. In 1923, its French subsidiary became a semi-autonomous partnership with the parent company and is now part of the French SAFRAN...
engines at the cost of 220,000 Norwegian krone
Norwegian krone
The krone is the currency of Norway and its dependent territories. The plural form is kroner . It is subdivided into 100 øre. The ISO 4217 code is NOK, although the common local abbreviation is kr. The name translates into English as "crown"...
r, just half of what the foreign bidders demanded. After cost estimates and calculations had been carried out, the Norwegian Ministry of Defence
Norwegian Ministry of Defence
The Royal Norwegian Ministry of Defence is a Norwegian government ministry in charge of the formation and implementation of national security and defence policy, and for the overall management and control of the activities of subordinate agencies. The ministry is located at Glacisgata 1, Oslo,...
approved the project on 8 March 1924. The project was then submitted to the Permanent Flying Commission and evaluated on 1 May 1924. Only Klingenberg, managing director of the Kjeller
Kjeller Airport
Kjeller Airport is a military and general aviation airport located in Kjeller, Norway, near Lillestrøm and east northeast of Oslo. It has facilities for carrying out maintenance for aircraft belonging to the Royal Norwegian Air Force....
Aircraft Factory, had a negative opinion of the design, being especially critical of the choice of a relatively weak engine. The manufacture of parts for the prototype M.F.9 began in August 1924 and the wing construction was tested at an aeronautical institute in Göttingen
Göttingen
Göttingen is a university town in Lower Saxony, Germany. It is the capital of the district of Göttingen. The Leine river runs through the town. In 2006 the population was 129,686.-General information:...
in the German Weimar Republic
Weimar Republic
The Weimar Republic is the name given by historians to the parliamentary republic established in 1919 in Germany to replace the imperial form of government...
, as well as being brought to breaking point in Horten. The Royal Norwegian Navy
Royal Norwegian Navy
The Royal Norwegian Navy is the branch of the Norwegian Defence Force responsible for naval operations. , the RNoN consists of approximately 3,700 personnel and 70 vessels, including 5 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support...
required the aircraft to have a top speed of 200 km/h, reach an altitude of 3,000 metres in 12 minutes and have a sturdy construction able to endure dog fighting. The aircraft also needed to be a stable platform and be easy to manoeuvre on water.
Design
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 recordFlight altitude record
These are the records set for going the highest in the atmosphere from the age of ballooning onward. Some records are certified by Fédération Aéronautique Internationale.-Fixed-wing aircraft:-Piston-driven propeller aeroplane:...
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.
Operational use
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 SvalbardSvalbard
Svalbard is an archipelago in the Arctic, constituting the northernmost part of Norway. It is located north of mainland Europe, midway between mainland Norway and the North Pole. The group of islands range from 74° to 81° north latitude , and from 10° to 35° east longitude. Spitsbergen is the...
to take part in the search for the missing polar explorer Roald Amundsen
Roald Amundsen
Roald Engelbregt Gravning Amundsen was a Norwegian explorer of polar regions. He led the first Antarctic expedition to reach the South Pole between 1910 and 1912 and he was the first person to reach both the North and South Poles. He is also known as the first to traverse the Northwest Passage....
and his two Dornier Wal
Dornier Do J
The Dornier Do J Wal was a twin-engine German flying boat of the 1920s designed by Dornier Flugzeugwerke. The Do J was designated the Do 16 by the Reich Air Ministry under its aircraft designation system of 1933....
flying boats.
The prototype, F.120, was used as a target aircraft during anti-aircraft artillery
Anti-aircraft warfare
NATO defines air defence as "all measures designed to nullify or reduce the effectiveness of hostile air action." They include ground and air based weapon systems, associated sensor systems, command and control arrangements and passive measures. It may be to protect naval, ground and air forces...
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.
Problems and retirement
In July and August 1928 another series of four M.F.9Bs (F.128, F.130, F.132 and F.134) were deliveredfrom the factory in Horten. Although M.F.9s were used during the annual summer exercises only the most experienced officer pilots were allowed to fly the type, all forms of acrobatics being banned and most pilots unwilling to perform any drastic manoeuvres. The first total loss of the type occurred on 27 August 1929 when F.120 crashed during landing. A replacement aircraft, F.120 (II) was finished in June 1930.
As the weak Hispano-Suiza engine prevented the M.F.9 from being a truly effective fighter aircraft work was carried out from the autumn of 1929 to the spring of 1931 to find a different engine to have in reserve and install in case of war. Two engines were tested, first a 425 hp Bristol Jupiter
Bristol Jupiter
The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments turned it into one of the finest engines of its era.The...
which at the time was the standard engine of the Norwegian Army Air Service
Norwegian Army Air Service
The Norwegian Army Air Service ' was established in 1914. Its main base and aircraft factory was at Kjeller. On 10 November 1944 the NoAAS was joined with the Royal Norwegian Navy Air Service to form the Royal Norwegian Air Force....
's Fokker C.V-E
Fokker C.V
Fokker C.V was a Dutch light reconnaissance and bomber biplane aircraft manufactured by Fokker. It was designed by Anthony Fokker and the series manufacture began in 1924 at Fokker in Amsterdam.-Development:...
scout-bombers, and secondly an Armstrong Siddeley Jaguar VII 14 cylinder air cooled engine.
However, accidents involving the aircraft entering uncontrolled spins continued with another aircraft being lost on 25 July 1930. At this point pilot confidence in the aircraft reached an all-time low, with seven officer pilots writing a letter of protest to the Ministry of Defence, voicing their opposition to the further use of the M.F.9. The criticism led to the halting of work on five M.F.9s then under construction (F.136, F.138, F.140 and replacement machines F.130 and F.132), although one almost complete M.F.9c (F.142) was finished in February 1932. F.142 and the incomplete aircraft had steel tube hulls instead of the wooden constructions of the earlier aircraft. An investigative commission concluded on 4 May 1932 that even the improved M.F.9c model was not usable for training purposes and recommended that the type should be discarded entirely. Director Høver strongly opposed this view, but did not win through with his view that further improvements could save the aircraft and the type was retired and put in reserve on 17 July 1932. The document sent by the Ministry of Defence to the RNNAS was signed by the Agrarian Party
Centre Party (Norway)
The Centre Party is a centrist and agrarian political party in Norway, founded in 1920. The Centre Party's policy is not based on any of the major ideologies of the 19th and 20th century, but has a focus on maintaining decentralised economic development and political decision-making.From its...
Minister of Defence
Minister of Defence (Norway)
The Norwegian Minister of Defence is a Councillor of the Council of State and Chief of the Norwegian Ministry of Defence, the position has existed since the Secretary of the Army and Secretary of the Navy was combined into the Minister of Defence...
, Vidkun Quisling
Vidkun Quisling
Vidkun Abraham Lauritz Jonssøn Quisling was a Norwegian politician. On 9 April 1940, with the German invasion of Norway in progress, he seized power in a Nazi-backed coup d'etat that garnered him international infamy. From 1942 to 1945 he served as Minister-President, working with the occupying...
.
The reason that the M.F.9 was put in reserve and not scrapped outright was the Sopwith Baby fighters had been scrapped a short time earlier, necessitating the retention of the M.F.9 as a reserve fighter force. Still, by the mid-1930s most of the aircraft were scrapped, the last four being retired in May 1939. The last M.F.9 operational, M.F.9c F.142, was used by the Marinens Flyvebaatfabrikk control officer until 28 May 1937 and then stored at the factory until 6 May 1939 when the Ministry of Defence approved of plans to preserve it as a museum piece. Although the final fate of F.142 is not known, it is assumed that it was burned by the German occupation forces
Occupation of Norway by Nazi Germany
The occupation of Norway by Nazi Germany started with the German invasion of Norway on April 9, 1940, and ended on May 8, 1945, after the capitulation of German forces in Europe. Throughout this period, Norway was continuously occupied by the Wehrmacht...
during the Second World War
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The M.F.9 was never replaced as a fighter in the RNNAS, the service instead choosing to focus on reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....
and torpedo aircraft
Torpedo bomber
A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...
.