Gnome-Rhône Mistral Major

The Gnome-Rhône 14K Mistral Major was a 14-cylinder, two-row, air-cooled radial engine. It was Gnome-Rhône's major aircraft engine prior to World War II, and matured into a highly sought-after design that would see licensed production throughout Europe and Japan. Thousands of Mistral Major engines were produced, used on a wide variety of aircraft.

Mistral Major
Gnome-Rhone 14 Mistral Major engines 1943
Gnome-Rhône 14Ks in a hangar in North Africa, 1943
Type Radial engine
Manufacturer Gnome et Rhône
First run 1929

Design and development

In 1921 Gnome-Rhône purchased a license for the highly successful Bristol Jupiter engine and produced it until about 1930, alongside the smaller Bristol Titan. Starting in 1926, however, they used the basic design of the Titan to produce a family of new engines, the so-called "K series". These started with the 5K Titan, followed by the 7K Titan Major and 9K Mistral. By 1930, 6,000 of these engines had been delivered.

However, the aircraft industry at that time was rapidly evolving and producing much larger aircraft that demanded larger engines to power them. Gnome-Rhône responded by developing the 7K into a two-row version that became the 14K Mistral Major. The first test examples were running in 1929.

As the Jupiter had set the pattern for one-row radials in the 1920s, the Mistral Major became a canonical design for twin-row radials of the 1930s. It was widely licensed and formed the basis for many successful designs. Among the licensees were Industria Aeronautică Română in Romania, Manfred Weiss in Hungary, Alvis of the UK, Tumansky in the USSR, Walter of Czechoslovakia, and Isotta Fraschini and Piaggio in Italy. Nakajima in Japan also licensed it, but did not put it into production, developing their own designs based on features taken from the Mistral and other designs.


French Variants
  • Kbr:
  • Kbrs:
  • Kdr: Non-supercharged with reduction gearing
  • Kds: Direct drive with supercharger
  • Kdrs: Supercharged with reduction gearing
  • Kes:
  • Kirs:
  • Knrs:
  • Krsd:
  • Kors: Opposite rotation
Licensed Variants


Aircraft powered by G-R 14K derivatives

Specifications (Gnome-Rhône 14Kd)

Data from [1][2]

General characteristics

  • Type: Fourteen-cylinder two-row air-cooled radial engine
  • Bore: 146 mm (5.748 in)
  • Stroke: 165 mm (6.496 in)
  • Displacement: 38.673 l (2,360.0 cu in)
  • Length: Kds - 1,317 mm (51.85 in)
    Kdr - 0.5 reduction gear - 1,528 mm (60.16 in)
    Kdr - 0.666· reduction gear - 1,530 mm (60.24 in)
    Kdrs - 0.5 reduction gear - 1,554 mm (61.18 in)
    Kdrs - 0.666· reduction gear - 1,556 mm (61.26 in)
  • Diameter: 1,288 mm (50.71 in)
  • Dry weight: Kdr 0.5 reduction gear - 503 kg (1,109 lb)
    Kdr 0.666· reduction gear - 508 kg (1,120 lb)
    Kdrs 0.5 reduction gear - 523 kg (1,153 lb)
    Kdrs 0.666· reduction gear - 528 kg (1,164 lb)
    Kds 502 kg (1,107 lb)



  • Power output: Kdr - 600 kW (800 hp) at sea level
    Kdrs - 580 kW (780 hp) at 1,500 m (4,900 ft) at 2,400 rpm
    Kdrs - 510 kW (680 hp) at 4,000 m (13,000 ft) at 2,400 rpm
    Kds - 560 kW (750 hp) at 1,500 m (4,900 ft) at 2,300 rpm
    Kds - 480 kW (650 hp) at 4,000 m (13,000 ft) at 2,300 rpm
  • Specific power: Kdr 15.5 kW/l (0.34 hp/in³)
  • Compression ratio: 5.5:1
  • Specific fuel consumption: 328 g/(kW•h) (0.54 lb/(hp•h))
  • Oil consumption: 20 g/(kW•h) (0.53 oz/(hp•h))
  • Power-to-weight ratio: 1.52 kW/kg (0.92 hp/lb)



A Piaggio P.XI engine at the Malmohus Technical Museum, Malmo, Sweden.

Tumanski M-85 Keski-Suomen ilmailumuseo

A Tumansky M-85 at the Aviation Museum of Central Finland.

Walter Mistral K 14-I (1934-37)

Walter Mistral Major.

Walter Mistral K-14 MLP 01

A Walter Mistral Major at the Polish Aviation Museum in Krakow.

See also

Related development

Related lists


  1. ^ Tsygulev (1939). Aviacionnye motory voennykh vozdushnykh sil inostrannykh gosudarstv (Авиационные моторы военных воздушных сил иностранных государств) (in Russian). Moscow: Gosudarstvennoe voennoe izdatelstvo Narkomata Oborony Soyuza SSR. Archived from the original on 2009-03-24.
  2. ^ Moteurs Gnome-Rhône series K (PDF) (in Spanish). Paris: Société Des Moteurs Gnome-Rhône. Retrieved 3 October 2014.
  • Danel, Raymond and Cuny, Jean. L'aviation française de bombardement et de renseignement 1918-1940 Docavia n°12, Editions Larivière
Aircraft industry of Serbia

Kingdom of Serbia became part of the new state, Kingdom of the Serbs, Croats and Slovenes. which was formed on 1 December 1918. Even though the industry was on a very low level of development, the state was among the first 10 countries in the world which developed their own aircraft production. Originally, only the parts produced in foreign factories were assembled, but very soon the production of domestic components began, so as the engineering. The forerunner of the domestic aircraft industry was the Airplane workshop (Aeroplanska radionica), which was established in 1920, at the airfield in Novi Sad. The assembling of the trial series of Hansa-Brandenburg C.I. The series was named SBr, as this type of plane was known in Serbia as srednji Brandenburg ("middle Brandenburg").From 1923 to 1941, there were 7 aircraft factories in Serbia, 4 of which were located in the capital, Belgrade, and 2 airplane engines factories. Also, some planes were produced in the aircraft workshops, aero clubs and private workshops. There were also factories for the aircraft equipment and workshops for the repairs and overhauls of the aircraft, engines and components. A major boost to the industry was a decision by the state from 1926 to acquire over 800 fighters and several hundreds of trainers and school planes. Additional foreign licenses were obtained. The advance of the industry was halted in 1932 when the state stopped with the further acquirement of the aircraft due to the Great Depression. The production rebound from 1937 onwards.According to the State union of the aircraft industries of the Kingdom of Yugoslavia, the state's aircraft industry and the auxiliary industries employed 300 engineers and technicians, 500 employees and 6,000 workers. In total, 1,729 military and civilian aircraft were produced in Serbia between two World Wars. Of those, none were cargo or reconnaissance aircraft. One of the most important people in the technical development of the aircraft design was engineer Milenko Mitrović "Spirta", who developed numerous designs for the airplanes in the 1928-40 period.

Alvis Pelides

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CANT Z.1011

The twin-engined CANT Z.1011 was one of two bombers of about the same size and powered by the same engines, designed by Filippo Zappata in the mid-1930s. The other was the three-engined CANT Z.1007, which in the end was the type preferred by the Regia Aeronautica.

Dornier Do 17

The Dornier Do 17, sometimes referred to as the Fliegender Bleistift ("flying pencil"), is a light bomber of Nazi Germany during World War II. It was produced by Claudius Dornier's company, Dornier Flugzeugwerke. The aircraft was designed as a Schnellbomber ("fast bomber"), a light bomber which, in theory, would be so fast that it could outrun defending fighter aircraft.

The Dornier was designed with two engines mounted on a "shoulder wing" structure and possessed a twin tail fin configuration. The type was popular among its crews due to its handling, especially at low altitude, which made the Do 17 harder to hit than other German bombers.

Designed in the early 1930s, it was one of the three main Luftwaffe bomber types used in the first three years of the war. The Do 17 made its combat debut in 1937 during the Spanish Civil War, operating in the Condor Legion in various roles. Along with the Heinkel He 111 it was the main bomber type of the German air arm in 1939–1940. The Dornier was used throughout the early war, and saw action in significant numbers in every major campaign theatre as a front line aircraft until the end of 1941, when its effectiveness and usage was curtailed as its bomb load and range were limited.

Production of the Dornier ended in mid-1940, in favour of the newer and more powerful Junkers Ju 88. The successor of the Do 17 was the much more powerful Dornier Do 217, which started to appear in strength in 1942. Even so, the Do 17 continued service in the Luftwaffe in various roles until the end of the war, as a glider tug, research and trainer aircraft. A considerable number of surviving examples were sent to other Axis nations as well as countries like Finland. Few Dornier Do 17s survived the war and the last was scrapped in Finland in 1952.

On 3 September 2010, the Royal Air Force Museum London announced the discovery of a Henschel-built Dornier Do 17Z buried in the Goodwin Sands off the coast of Kent, England. On 10 June 2013, the salvage team raised the airframe from the seabed.

Gnome-Rhône 14N

The Gnome-Rhône 14N was a 14-cylinder two-row air-cooled radial engine designed and manufactured by Gnome-Rhône. A development of the pre-war Gnome-Rhône 14K, the 14N was used on several French and German aircraft of World War II.

IAR 37

The IAR 37 was a 1930s Romanian reconnaissance or light bomber aircraft built by Industria Aeronautică Română.


The IAR K14 was a Romanian 14-cylinder radial aircraft engine. The IAR K14 was a licensed derivative of the French Gnome-Rhône 14K Mistral Major produced in Romania.

Ilyushin DB-3

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Piaggio P.XI

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Further development led to the P.XIX. This featured an increased compression ratio from 6:1 to 7:1 and an rpm increase from 2,400 to 2,600.

Piaggio P.XIX

The Piaggio P.XIX was an Italian aircraft engine produced by Rinaldo Piaggio S.p.A. during World War II and used to power aircraft of the Regia Aeronautica.

Polikarpov I-180

The Polikarpov I-180 (Russian: И-180) was a 1938 Soviet fighter prototype. It was the last attempt to extract performance from the basic Polikarpov I-16 design. The development cycle was plagued with problems, especially with the death of the star Soviet test pilot Valery Chkalov in one of the prototypes.

Potez 50

The Potez 50 or Potez 50 A2 was a French two seat military multi-rôle aircraft, first flown in 1931. It did not go into service but seven variants using five different engines were produced, one of them setting several speed with useful load records and another, the Potez 506, setting three altitude world records.

Renard R.31

The Renard R.31 was a Belgian reconnaissance aircraft of the 1930s. A single-engined parasol monoplane, 32 R.31s were built for the Belgian Air Force, the survivors of which, although obsolete, remained in service when Nazi Germany invaded Belgium in 1940. The Renard R.31 was the only World War II operational military aircraft entirely designed and built in Belgium.

Savoia-Marchetti SM.79

The Savoia-Marchetti SM.79 Sparviero (Italian for sparrowhawk) was a three-engined Italian medium bomber developed and manufactured by aviation company Savoia-Marchetti. It could be the best-known Italian aeroplane of the Second World War. The SM.79 was easily recognizable due to its distinctive fuselage dorsal "hump", and was reportedly well liked by its crews, who nicknamed it il gobbo maledetto ("damned hunchback").The SM.79 had been originally developed during the early 1930s as a cantilever low-wing monoplane employing a combined wood-and-metal structure. It had been designed with the initial intention of producing a swift eight-passenger transport aircraft, capable of besting even the fastest of its contemporaries at that time, however, the project quickly attracted the attention of the Italian government for its potential as an armed combat aircraft. Performing its first flight on 28 September 1934; between 1937 and 1939, early examples of the type established 26 separate world records, qualifying it for some time as being the fastest medium bomber in the world. As such, the SM.79 quickly became regarded as an item of national prestige in Fascist Italy, attracting significant government support and often being deployed as an element of state propaganda. Early on, the aircraft was routinely entered into competitive fly-offs and air races, seeking to capitalise on its advantages, and often emerged victorious in such contests.

The SM.79 first saw combat during the Spanish Civil War; in this theatre, it operated without fighter escorts, normally relying on its relatively high speed to evade interception instead. While some issues were identified, and in some cases resolved, the SM.79's performance during the Spanish deployment was encouraging and stimulated demand for the type, including a decision to adopt it as the backbone of Italy's bomber units. Both Yugoslavia and Romania opted to procure the type for their own air services, while large numbers were also procured for the Regia Aeronautica. Almost 600 SM.79-I and –II aircraft were in service when Italy entered the Second World War during May 1940; thereafter, these aircraft were deployed across every theatre of war in which the Italians fought.

The SM.79 was operated in various different capacities during the Second World War; initially, the type was used as a transport aircraft and medium bomber. Following pioneering work by the "Special Aerotorpedoes Unit", Italy put the type to work as a torpedo bomber; in this role, the SM.79 achieved notable successes against Allied shipping, particularly in the Mediterranean theater. A specialised drone version of the aircraft, flown by remote control was also developed, although the Armistice with Italy was enacted prior to any operational deployment. It was the most numerous Italian bomber of the Second World War, around some 1,300 aircraft were constructed. The type would remain in Italian service until 1952.

Tumansky M-88

The Tumansky M-88 was an air-cooled radial engine for aircraft developed in the Soviet Union shortly before World War II.

Tupolev MTB-2

The Tupolev MTB-2 (Russian: Морской Тяжелый Бомбардировщик — Heavy Naval Bomber), also known as the ANT-44, was a four-engine prototype flying boat designed in the Soviet Union in 1935.

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