Marinens Flyvebaatfabrikk M.F.10
Encyclopedia
The Marinens Flyvebaatfabrikk M.F.10 (also known as the Høver M.F.10, after its designer) was a military trainer seaplane built in Norway in 1929.
fighter, and sharing its single-bay wings with additional struts bracing the lower wings to the fuselage sides. It differed from its predecessor in having two a second open cockpit in tandem with the pilot's, and while the prototype shared the M.F.9's wooden construction and Vee-engine, later examples had a tubular structure and a radial engine. Intended for advanced training, the aircraft was built strongly enough to allow for aerobatics and dive bombing. Having been built by the specifications from a US
light dive bomber, the M.F.10 could both dive and fly on its back.
began construction of a new trainer to replace the Hansa-Brandenburg W.33
in this role. The prototype, F.4 (V), first flew on 7 July 1929 and underwent stringent testing before moving on to the production stage. F.4 first flew with a 160 hp Mercedes engine with a top speed of 157 km/h and a climbing speed of 2,000 meters in 25 minutes. The Mercedes power plant was replaced with a Hispano Suiza model with a top speed of 185 km/h and an ability to climb 2,000 metres in less than eight minutes.
's (RNNAS) goal for the type was to have one aircraft based at each of the three Norwegian naval air stations, leading to the delivery of two new aircraft, one in 1932 and another in 1933. The two new-built aircraft were delivered with Armstrong Siddeley Cheetah engines and a steel tube hull instead of F.200's wooden hull. Designated as M.F.10Bs and numbered F.202 and F.204, the two aircraft were modified with a new type balance rudder which greatly improved their flying characteristics. When F.202 was written off after a May 1935 crash a replacement aircraft was built and delivered in March 1936 as the fourth and last of the type. The same year F.200 had its wooden hull replaced with a steel tube one. In addition to its training role the M.F.10 was also used for operational tests, such as seaplanes' ability to land on and take off from snow and ice on frozen lakes. Successful tests were carried out in March 1933 with F.202 both on Borresvannet lake and on the snow-covered Kjeller
air station.
, something which on 14 October 1938 led to an accident with F.200 during a training mission with a student pilot. When the student was to bring the aircraft out of its spin the rudders failed to respond and the engine ceased. At 400 metres altitude the student was ordered to parachute, while the aircraft regained control at the same moment the student, 2nd Lt. Follevåg, jumped. The instructor, 1st. Lt. Brinch landed on the water and picked up the student.
two M.F.10s (F.202 and F.204) were still in service with the RNNAS and deployed for neutrality guard duties, both first being based at Karljohansvern
naval air station but with F.204 relocation to Kristiansand
on 7 March 1940. In the evening of 8 April 1940 it became clear to the commander of Karljohansvern naval air station, Lieutenant Commander Gösta Wendelbo, that the situation was becoming critical and he ordered all flyable aircraft under his command to fly to Oscarsborg Fortress
to await the situation. The decision led to the dispatched aircraft becoming caught up in the Battle of Drøbak Sound
and lost. Seven aircraft, including M.F.10 F.202, landed near Oscarsborg Fortress and were there when intense fighting between a German invasion flotilla and Norwegian coastal fortifications
began. The aircraft were blocked in the area and soon froze in, making it impossible for them to escape. On 11 April 1940 the leader of the unit's four remaining aircraft, including F.202, disbanded the unit. Four airmen remained trying to get one aircraft airborne, but after a week they removed the machine guns and bombs from the aircraft and left the area, the aircraft eventually being picked up by the Germans and moved to Horten
. F.200 did not take part in the neutrality protection duties due to undergoing major maintenance at Marinens Flyvebaatfabrikk in Horten and was captured there on 9 April 1940. F.204, based in Kristiansand, was flown to a fjord
west of the port of Lillesand
when the German invasion began and destroyed there by its own crew on 10 April 1940.
, one M.F.10 was flown by the Germans from Horten to Gressholmen Airport
near Oslo. At Gressholmen the aircraft was repainted and given the Norwegian word Fiskerioppsyn on one side and Fischereidienst on the other, both words meaning fisheries service. The Germans' intention was to use the M.F.10 and one Douglas DT-2
(number F.84) for fisheries surveillance duties off the coast of Møre
. The project probably never got under way as the Luftwaffe
demanded to have total control over the Norwegian airspace and were unlikely to have allowed any form of para-military organisation to fly over Norway. Although there were widespread contemporary rumours claiming that the aircraft were to be used for surveillance of Norwegian fishing boats, these have not been confirmed after searches of Norwegian and German archives.
Characteristics
It was a largely conventional biplane design derived from the M.F.9Marinens Flyvebaatfabrikk M.F.9
The Marinens Flyvebaatfabrikk M.F.9 Høverjager , also known as the Høver M.F.9 after its designer, was a fighter seaplane built in Norway in the 1920s.-Background:...
fighter, and sharing its single-bay wings with additional struts bracing the lower wings to the fuselage sides. It differed from its predecessor in having two a second open cockpit in tandem with the pilot's, and while the prototype shared the M.F.9's wooden construction and Vee-engine, later examples had a tubular structure and a radial engine. Intended for advanced training, the aircraft was built strongly enough to allow for aerobatics and dive bombing. Having been built by the specifications from a US
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
light dive bomber, the M.F.10 could both dive and fly on its back.
Design and construction
Marinens FlyvebaatfabrikkMarinens 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:...
began construction of a new trainer to replace the Hansa-Brandenburg W.33
Hansa-Brandenburg W.33
-See also:-References:* Keskinen, Kalevi; Niska, Klaus; Stenman, Kari; Geust, Carl-Fredrik: Suomen museolentokoneet, Forssan kirjapaino, 1981, ISBN 951-9035-60-5....
in this role. The prototype, F.4 (V), first flew on 7 July 1929 and underwent stringent testing before moving on to the production stage. F.4 first flew with a 160 hp Mercedes engine with a top speed of 157 km/h and a climbing speed of 2,000 meters in 25 minutes. The Mercedes power plant was replaced with a Hispano Suiza model with a top speed of 185 km/h and an ability to climb 2,000 metres in less than eight minutes.
Operational use
Early service
From May 1930 the prototype was given the registration number F.200, in line with the new number series to be used for two-seat trainers. 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 :...
's (RNNAS) goal for the type was to have one aircraft based at each of the three Norwegian naval air stations, leading to the delivery of two new aircraft, one in 1932 and another in 1933. The two new-built aircraft were delivered with Armstrong Siddeley Cheetah engines and a steel tube hull instead of F.200's wooden hull. Designated as M.F.10Bs and numbered F.202 and F.204, the two aircraft were modified with a new type balance rudder which greatly improved their flying characteristics. When F.202 was written off after a May 1935 crash a replacement aircraft was built and delivered in March 1936 as the fourth and last of the type. The same year F.200 had its wooden hull replaced with a steel tube one. In addition to its training role the M.F.10 was also used for operational tests, such as seaplanes' ability to land on and take off from snow and ice on frozen lakes. Successful tests were carried out in March 1933 with F.202 both on Borresvannet lake and on the snow-covered 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....
air station.
Handling issues
The type had a degree of difficulties as to getting out of a spinSpin (flight)
In aviation, a spin is an aggravated stall resulting in autorotation about the spin axis wherein the aircraft follows a corkscrew downward path. Spins can be entered intentionally or unintentionally, from any flight attitude and from practically any airspeed—all that is required is sufficient yaw...
, something which on 14 October 1938 led to an accident with F.200 during a training mission with a student pilot. When the student was to bring the aircraft out of its spin the rudders failed to respond and the engine ceased. At 400 metres altitude the student was ordered to parachute, while the aircraft regained control at the same moment the student, 2nd Lt. Follevåg, jumped. The instructor, 1st. Lt. Brinch landed on the water and picked up the student.
In Norwegian service
At the outbreak of the Second World WarWorld 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...
two M.F.10s (F.202 and F.204) were still in service with the RNNAS and deployed for neutrality guard duties, both first being based at Karljohansvern
Karljohansvern
Karjohansvern in Horten was the main base for the Royal Norwegian Navy from 1819 to 1963.It was first called Hortens verft, and later Marinens Hovedværft until King Oscar I named it Carljohansværn værft in 1854...
naval air station but with F.204 relocation to Kristiansand
Kristiansand
-History:As indicated by archeological findings in the city, the Kristiansand area has been settled at least since 400 AD. A royal farm is known to have been situated on Oddernes as early as 800, and the first church was built around 1040...
on 7 March 1940. In the evening of 8 April 1940 it became clear to the commander of Karljohansvern naval air station, Lieutenant Commander Gösta Wendelbo, that the situation was becoming critical and he ordered all flyable aircraft under his command to fly to Oscarsborg Fortress
Oscarsborg Fortress
Oscarsborg Fortress is a coastal fortress in the Oslofjord, close to the small town of Drøbak. The fortress is situated on two small islets, and on the mainland to the west and east, in the fjord and was military territory until 2003 when it was made a publicly available resort island...
to await the situation. The decision led to the dispatched aircraft becoming caught up in the Battle of Drøbak Sound
Battle of Drøbak sound
The Battle of Drøbak Sound took place in the northernmost part of the Oslofjord on 9 April 1940, on the first day of the German invasion of Norway...
and lost. Seven aircraft, including M.F.10 F.202, landed near Oscarsborg Fortress and were there when intense fighting between a German invasion flotilla and Norwegian coastal fortifications
Coastal artillery
Coastal artillery is the branch of armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications....
began. The aircraft were blocked in the area and soon froze in, making it impossible for them to escape. On 11 April 1940 the leader of the unit's four remaining aircraft, including F.202, disbanded the unit. Four airmen remained trying to get one aircraft airborne, but after a week they removed the machine guns and bombs from the aircraft and left the area, the aircraft eventually being picked up by the Germans and moved to 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....
. F.200 did not take part in the neutrality protection duties due to undergoing major maintenance at Marinens Flyvebaatfabrikk in Horten and was captured there on 9 April 1940. F.204, based in Kristiansand, was flown to a fjord
Fjord
Geologically, a fjord is a long, narrow inlet with steep sides or cliffs, created in a valley carved by glacial activity.-Formation:A fjord is formed when a glacier cuts a U-shaped valley by abrasion of the surrounding bedrock. Glacial melting is accompanied by rebound of Earth's crust as the ice...
west of the port of Lillesand
Lillesand
is a town and municipality in Aust-Agder county, Norway. It is part of the traditional district of Sørlandet. The administrative center of the municipality is the town of Lillesand.-General information:...
when the German invasion began and destroyed there by its own crew on 10 April 1940.
Possible German use
After the beginning of the German invasion of NorwayOperation Weserübung
Operation Weserübung was the code name for Germany's assault on Denmark and Norway during the Second World War and the opening operation of the Norwegian Campaign...
, one M.F.10 was flown by the Germans from Horten to Gressholmen Airport
Gressholmen Airport
Gressholmen Airport was the main airport serving Oslo, Norway from 1927 to 1939, until the construction of Fornebu Airport. The airport was on the islet of Gressholmen, and was only for seaplanes...
near Oslo. At Gressholmen the aircraft was repainted and given the Norwegian word Fiskerioppsyn on one side and Fischereidienst on the other, both words meaning fisheries service. The Germans' intention was to use the M.F.10 and one Douglas DT-2
Douglas DT
|-References:* René Francillon, "McDonnell Douglas Aircraft Since 1920: Volume I", ISBN 0-87021-428-4...
(number F.84) for fisheries surveillance duties off the coast of Møre
Møre og Romsdal
is a county in the northernmost part of Western Norway. It borders the counties of Sør-Trøndelag, Oppland and Sogn og Fjordane. The county administration is located in Molde, while Ålesund is the largest city.-The name:...
. The project probably never got under way as the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
demanded to have total control over the Norwegian airspace and were unlikely to have allowed any form of para-military organisation to fly over Norway. Although there were widespread contemporary rumours claiming that the aircraft were to be used for surveillance of Norwegian fishing boats, these have not been confirmed after searches of Norwegian and German archives.