SNCASO (abbreviated from ''Société nationale des constructions aéronautiques du Sud-Ouest'' ), or commonly ''Sud-Ouest'', was a French
aircraft manufacturer
An aerospace manufacturer is a company or individual involved in the various aspects of designing, building, testing, selling, and maintaining aircraft, aircraft parts, missiles, rockets, or spacecraft. Aerospace is a high technology industry.
...
.
Created during 1936 as one of seven nationalised aeronautical manufacturing companies, SNCASO became a key French aircraft manufacturer following the end of the
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. It produced numerous innovation aircraft; amongst the company's more notable projects was the first French
jet aircraft
A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by one or more jet engines.
Whereas the engines in Propeller (aircraft), propeller-powered aircraft generally achieve their maximum efficiency at much ...
, the
Sud-Ouest Triton, and the first indigenously-developed French helicopter, the
Sud-Ouest Djinn.
On 1 March 1957, SNCASO merged with another French nationalised aviation company,
SNCASE
SNCASE (abbreviated from ''Société nationale des constructions aéronautiques du Sud-Est'') or Sud-Est was a French aircraft manufacturer. The company was formed on February 1, 1937, by the nationalization and merger of Lioré et Olivier, Pote ...
, (''Société nationale des constructions aéronautiques du Sud-Est''), to form
Sud Aviation
Sud Aviation (, 'Southern Aviation') was a French state-owned aircraft manufacturer, originating in the merger of Sud-Est ( SNCASE, or ''Société nationale des constructions aéronautiques du sud-est'') and Sud-Ouest ( SNCASO or ''Société nat ...
.
History
Following the
resolution of the 1936
general strike
A general strike is a strike action in which participants cease all economic activity, such as working, to strengthen the bargaining position of a trade union or achieve a common social or political goal. They are organised by large coalitions ...
of French heavy industry, the government of
Léon Blum introduced an act to nationalize the French war industry.
The act provided for the creation of seven nationalised aeronautical manufacturing companies: six for aircraft (
SNCASE
SNCASE (abbreviated from ''Société nationale des constructions aéronautiques du Sud-Est'') or Sud-Est was a French aircraft manufacturer. The company was formed on February 1, 1937, by the nationalization and merger of Lioré et Olivier, Pote ...
, SNCASO,
SNCAN,
SNCAO,
SNCAM
Société nationale des constructions aéronautiques du Midi (abbreviated SNCAM) was a state-owned French aircraft manufacturer. The company was formed following the resolution of the 1936 general strike of French heavy industry, when the govern ...
,
SNCAC
SNCAC (the ', sometimes known as ) was a French aircraft manufacturer. SNCAC was created by the nationalisation of the Farman Aviation Works and Hanriot firms in 1936.
The company had a manufacturing facility in Boulogne-Billancourt which was ...
), and one for aircraft engines (
SNCM -
Lorraine-Dietrich).
In accordance with this agreement, SNCASO was formed on 16 November 1936 from the
merger
Mergers and acquisitions (M&A) are business transactions in which the ownership of a company, business organization, or one of their operating units is transferred to or consolidated with another entity. They may happen through direct absorpt ...
of the factories of
Blériot of
Suresnes
Suresnes () is a commune in the western inner suburbs of Paris, France. Located in Hauts-de-Seine, from the centre of Paris, it had a population of 49,482 as of 2020.
Suresnes borders the Bois de Boulogne in the 16th arrondissement of Paris, ...
,
Bloch
Bloch is a surname of German origin. Notable people with this surname include:
A
*Adele Bloch-Bauer (1881–1925), Austrian entrepreneur
*Albert Bloch (1882–1961), American painter
*Alexandre Bloch (1857–1919), French painter
*Alfred Bloch ( ...
of
Villacoublay and
Courbevoie
Courbevoie () is a Communes of France, commune located in the Hauts-de-Seine department of the Île-de-France region of France. It is a suburb of Paris, from the Kilometre zero, center of Paris. The centre of Courbevoie is situated from the ci ...
, SASO (''Société Aéronautique du Sud-Ouest'') of
Bordeaux
Bordeaux ( ; ; Gascon language, Gascon ; ) is a city on the river Garonne in the Gironde Departments of France, department, southwestern France. A port city, it is the capital of the Nouvelle-Aquitaine region, as well as the Prefectures in F ...
-
Mérignac, UCA (''Usine de Construction Aéronautique'') of
Bordeaux
Bordeaux ( ; ; Gascon language, Gascon ; ) is a city on the river Garonne in the Gironde Departments of France, department, southwestern France. A port city, it is the capital of the Nouvelle-Aquitaine region, as well as the Prefectures in F ...
-
Bègles
Bègles (; Gascon language, Gascon: ''Begla'') is a Communes of France, commune in the Gironde Departments of France, department in southwestern France.
It is a suburb of the city of Bordeaux and is adjacent to it on the south. Bègles station h ...
,
Société Aérienne Bordelaise (SAB) of
Bordeaux
Bordeaux ( ; ; Gascon language, Gascon ; ) is a city on the river Garonne in the Gironde Departments of France, department, southwestern France. A port city, it is the capital of the Nouvelle-Aquitaine region, as well as the Prefectures in F ...
-
Bacalan and
Lioré et Olivier of
Rochefort. Additionally, SNCASO constructed a new factory in
Déols during that same year.
The company's fortunes, along with that of the wider French nation, were heavily affected by the events of the
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, particularly the formation of the
occupation of France by German forces. Despite the country's hardship during the conflict, SNCASO continued to operate. During 1941, the
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
design bureaus of both the nationalized and the private aircraft firms were relocated; according to aviation historian Gérard Hartmann, this measure was taken to avoid capture.
That same year, SNCASO took over the assets of the ailing
SNCAO. The company worked on various projects throughout the war, often under a heavy level of secrecy, including into the new field of
jet propulsion. France, akin to the other
Allied nations in the war, had benefitted from captured Germany high speed research; these factors combined gave a great impetus to undertaking advanced research projects.
[Caygill 2006, .]

Amongst the first new aviation projects to be launched in France during the
postwar
A post-war or postwar period is the interval immediately following the end of a war. The term usually refers to a varying period of time after World War II, which ended in 1945. A post-war period can become an interwar period or interbellum, ...
era was SNCASO's jet-powered
Sud-Ouest Triton.
According to aviation author John W.R. Taylor, the origins of the Triton can be traced back to a clandestine research effort conducted during 1943, headed by the French aeronautics engineer
Lucien Servanty. Shortly after the end of the conflict, the new French government issued a requirement, calling for a total of five
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototype ...
aircraft to be constructed for testing purposes.
The development of indigenously designed jet aircraft was seen as of national importance to the government, being intended to symbolise and embody the speedy recovery of France's industrial and military strength.
["Vol historique du premier avion à réaction français, le "SO 6000 Triton."](_blank)
''gouvernement.fr'', Retrieved: 18 May 2019.
To speed up development of the Triton, which would become the first French jet-powered aircraft to fly, it was decided to use the
German-designed
Junkers Jumo 004-B2 engine after severe development issues were encountered with the indigenously developed
Rateau-Anxionnaz GTS-65 turbojet
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...
engine. The
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies.
* British national identity, the characteristics of British people and culture ...
Rolls-Royce Nene turbojet engine was also adopted for multiple of the prototypes. On 11 November 1946, the first prototype Triton performed its
maiden flight
The maiden flight, also known as first flight, of an aircraft is the first occasion on which it leaves the ground under its own power. The same term is also used for the first launch of rockets.
In the early days of aviation it could be dange ...
.
However, further development of the Triton was ultimately abandoned during the early 1950s; it was never use in any operational circumstance. The design had been rendered obsolete by the rapid pace of advancements, both in terms of jet propulsion specifically and wider aerospace capabilities generally, with numerous jet-powered designs being produced around this timeframe.
SNCASO also branched out into helicopters. It gained useful experiences from the experimental
Sud-Ouest Ariel, a
tip jet helicopter, that enabled the firm's design team to pursue development of a practical light helicopter that would harness this technology. They designed a compact and lightweight twin-seat rotorcraft, which was promptly designated as the
Sud-Ouest Djinn.
[Boyne 2011, p. 101.] While this newer design did not share an identical tip jet system to the Ariel, the type did rely upon the same basic concept of feeding compressed air, which was generated by an onboard pump, to the tips of the vehicle's rotor blades to drive the movement of the blades.
["Helicopter Runs On Air."](_blank)
''Popular Science'', April 1953. First flying in January 1953, the Djinn proved itself to be a viable design; after several further prototypes were completed and tested, the type went into mass production.
[McGowen 2005, p. 74.] The Djinn was the first indigenously developed French helicopter, as well as being one of the first practical European helicopters to be produced. It was also the first
tip-jet propelled rotorcraft to enter production.
["Hew French Helicopters."](_blank)
''Flight International'', 17 April 1959. p. 512.
Almost immediately after the war, the resurgent
French Air Force
The French Air and Space Force (, , ) is the air force, air and space force of the French Armed Forces. Formed in 1909 as the ("Aeronautical Service"), a service arm of the French Army, it became an independent military branch in 1934 as the Fr ...
also produced a requirement for a jet bomber with a takeoff weight of roughly 25–30
tonne
The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...
s and capable of flying at high-
subsonic speeds; its development was viewed as a major technological challenge as it called for the production of France's first jet bomber.
[Gunston and Gilchrist 1993, p. 68.] SNCASO was amongst several French aircraft manufacturers to tender, submitting its
SO.4000; it received a development order for a pair of manned scale models and a full-sized
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototype ...
. During 1947, as a result of the rapid advances made in aviation technologies made around this time, plans for the SO.4000's production run were abandoned; nevertheless, it was decided to complete the two scale models and the full size prototype for experimental purposes.
"Le Sud-Ouest SO-4000: V. Essai et abandon du SO-4000"
''Le Sit des Projets et Prototypes d'Avions'', 14 May 2003. Retrieved 15 May 2011. Both scale models provided valuable data on features such as swept wing
A swept wing is a wing angled either backward or occasionally forward from its root rather than perpendicular to the fuselage.
Swept wings have been flown since the pioneer days of aviation. Wing sweep at high speeds was first investigated in Ge ...
s, pilot escape systems, spoiler control, and leading edge slats. On 5 March 1950, the SO.4000 was rolled out; by this point, it was already obsolete and lacking in capabilities compared to its contemporaries. Following an accident that damaged the airframe, work on the project was abandoned.[''Air International'' January 1986, p. 46.] According to Gunston and Gilchrist, the SO.4000 was a very heavy aircraft, which only compounded the weakness of possessing relatively little engine power, giving it an extremely poor thrust-to-weight ratio even when empty; they also criticised it as possessing "useless capabilities".[Gunston and Gilchrist 1993, p. 69.]
During June 1951, the French ''Armée de l'Air'' (AdA) issued a separate requirement for a jet-powered aircraft capable of functioning as a bomber, a low-level attack aircraft, or an all-weather interceptor.[Gunston and Gilchrist 1993, p. 124.] In response, SNCASO adapted its existing ''S.O. 4000'' design to perform the desired roles. During 1951, prototype testing had demonstrated promising performance for the type, which encouraged its further development.["IAF Aircraft Inventory: Sud-Ouest S.O. 4050 Vautour."](_blank)
Jewish Virtual Library, Retrieved: 16 September 2017. Named the Vautour, the IIB bomber variant was used to carry France's nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...
s in addition to a conventional arsenal; as such, for some years the Vautour was an important element of the nation's nuclear deterrent
Nuclear strategy involves the development of doctrines and strategies for the production and use of nuclear weapons.
As a sub-branch of military strategy, nuclear strategy attempts to match nuclear weapons as means to political ends. In addit ...
. According to aviation authors Bill Gunston and Peter Gilchrist, "It would be fair to claim that in the early 1950s the Vautour was the most promising twin-jet warplane in Western Europe".[Gunston and Gilchrist 1993, p. 125.]
SNCASO developed several variants of the Vautour for different purposes, including the interceptor
Interceptor may refer to:
Arts and entertainment
Film and television
* ''The Interceptor'', a British drama series on BBC One
* Interceptor (game show), ''Interceptor'' (game show), a British television game show that ran during 1989
* Interc ...
role; several were proposed but ultimately unbuilt. During 1956, two years prior to the Vautour even entering squadron service, France issued a more demanding requirement for a supersonic replacement aircraft. The Vautour was viewed as a stop-gap measure for the nuclear deterrent role, as its performance in this role was typically thought to be limited at best, while this more capable follow-on aircraft was under development. While the newer bomber requirement would ultimately result in the selection, development and manufacture of the Dassault Mirage IV bomber; SNCASO chose to respond to the requirement, producing their own proposal of an envisioned ''Super Vautour''. According to aviation author Bill Gunston, the unbuilt 'stretched' Super Vautour would have featured an increased combat radius of 1,700 miles as well as the ability to attain at least Mach
The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a Boundary (thermodynamic), boundary to the local speed of sound.
It is named after the Austrian physi ...
0.9.[Gunston 1973, p. 104.]
During the rationalisation of the nationalised Aircraft Industry during the 1950s, SNCASO was merged with SNCASE to form Sud Aviation
Sud Aviation (, 'Southern Aviation') was a French state-owned aircraft manufacturer, originating in the merger of Sud-Est ( SNCASE, or ''Société nationale des constructions aéronautiques du sud-est'') and Sud-Ouest ( SNCASO or ''Société nat ...
on 1 March 1957. Over the subsequent decades, Sud Aviation was in turn was amalgamated into French defense conglomerate Aérospatiale
Aérospatiale () was a major French state-owned aerospace manufacturer, aerospace and arms industry, defence corporation. It was founded in 1970 as () through the merger of three established state-owned companies: Sud Aviation, Nord Aviation ...
and eventually became a part of the multinational EADS
Airbus SE ( ; ; ; ) is a Pan-European aerospace corporation. The company's primary business is the design and manufacturing of commercial aircraft but it also has separate defence and space and helicopter divisions. Airbus has long been th ...
group, today trading as the Airbus Group.
Aircraft products
* SO.30 Bretagne
* SNCASO SO.60C - 1950s abandoned project for a twin-engine jet airliner
* SO.80 Biarritz
* SO.90 Corse
* SO.95 Corse II
* SO.177
* SO.1100 Ariel
* SO.1110 Ariel
* SO.1120 Ariel
* SO.1220 Djinn
* SO.1310 Farfardet
* SO.3050
* SO.4000
* SO.4050 Vautour
* SO.6000 Triton
* SO.6020 Espadon
* SO.7010 Pégase
* SO.7050 Deauville
* SO.7055 Deauville
* SO.7060 Deauville
* SO.8000 Narval
* SO.9000 Trident I
* SO.9050 Trident II
* SO.M-1
* SO.M-2
* SO.P-1 Ferblantine
References
Citations
Bibliography
* "An abortive bomber". ''Air International
''AIR International'' is a British aviation magazine covering current defence aerospace and civil aviation topics. It has been in publication since 1971 and is currently published by Key Publishing Ltd.
History and profile
The magazine was fir ...
'', January 1986, Vol 30 No 1. Bromley, UK: Fine Scroll. p. 46. ISSN 0306-5634.
* Boyne, Walter. ''How the Helicopter Changed Modern Warfare''. Pelican Publishing Company, 2011. .
* Caygill, Peter. ''Sound Barrier: The Rocky Road to MACH 1.0+''. Pen and Sword, 2006. .
* Gunston, Bill. ''Bombers of the West''. New York. Charles Scribner's and Sons, 1973. .
* Gunston, Bill and Peter Gilchrist. ''Jet Bombers: From the Messerschmitt Me 262 to the Stealth B-2''. Osprey, 1993. .
*
External links
SNCASO page
o
AviaFrance
{{DEFAULTSORT:Sncaso
Defunct aircraft manufacturers of France
Sud Aviation
Vehicle manufacturing companies established in 1936
Vehicle manufacturing companies disestablished in 1957
French companies established in 1936
1957 disestablishments in France