The Sud-Ouest SO 6000 Triton: France's First Jet Aircraft

Sud-Ouest SO 6000 Triton prototype. Note the nose intake.

France's first jet aircraft has its roots during the German occupation during the Second World War. Sequestered away in a small Paris apartment a group of French engineers led by Lucien Servanty began work on what would become the Sud-Ouest SO 6000 Triton. Servanty was a graduate of the prestigious engineering school Ecole des Arts et Métiers and prior to the war started out working at Breguet before moving to SNCASO (Société nationale des constructions aéronautiques du sud-ouest) which was a conglomeration formed in 1936 out of several French aircraft companies including Blériot, Bloch, and Lioré et Olivier but was better known as Sud-Ouest. Sud-Ouest was one of the precursor entities to the post war Sud Aviation that would later become Aerospatiale. It was here at Sud-Ouest that Servanty worked on the last variants of the Bloch MB.150 fighter before the fall of France in 1940 to the Nazis. Some of the French aeronautical establishment fled to the Great Britain, some went south to work with the Vichy regime, some were imprisoned for refusing to collaborate (like Marcel Bloch, who later changed his name to Marcel Dassault), and others like Lucien Servanty went into hiding. This was the sort of environment that the Triton was developed, in secret places tucked away from the Nazi occupiers. Servanty's team even built small scale models and tested them in wind tunnels they constructed in secret. 

Lucien Servanty

Uniquely for pioneering jet aircraft of the time from other nations, the Triton was to be a side-by-side two seat aircraft with dual controls and a retracting tricycle undercarriage. A two seater was quite a departure from the first jets in the United States, Great Britain, Germany and the Soviet Union which were all single seaters. The cabin of the Triton wasn't really that much different from a two-seat cabin general aviation aircraft- this was Servanty's idea that the Triton might find use as more than a research aircraft but a training aircraft to introduce pilots to jet propulsion. As designed, the all-metal Triton was to use an indigenous French engine called the Rateau (named for Auguste Rateau who had done much work in the first half of the century on industrial turbines) which was also being developed clandestinely during the occupation. The intake for the Rateau engine was under the nose with the intake duct passing between the pilots to the centrally-mounted engine abreast the wings. Furthering the impression of the Triton as a general aviation aircraft was its crew access via car door-like hatches on each side of the cockpit. In fact, one writer even suggested the Triton may well be the first VLJ-class aircraft thanks to its design!

With the end of the war and the liberation of France, the new French government immediately placed an order for five Triton aircraft plus one static airframe as part of broader effort to rebuild the nation's aeronautical industry. Construction began in somewhat humble facilities outside Paris that were once the factories for Nieuport biplane fighters before moving to a more suitable facility that was once used by Farman. Like many pioneering jet aircraft of the day, the airframe work proceeded much more quickly than the engine development effort. Engineers working on the 3250 lb-thrust Rateau engine were running into difficulties and the Triton prototype was slightly modified to accept a German Jumo 004 engine as used on the Messerschmitt Me 262. This was something of a fortuitous coincidence for Lucien Servanty's team as the Jumo plants in Germany happened to be located in the French occupation sector. The first two Triton airframes would be powered by the Jumo 004. The first flight took place on 11 November 1946 with test pilot Daniel Rastel at the controls. Prior to his first Triton flights, he acquainted himself with jet propulsion by flying captured Me 262s. With this first flight, France become the fifth nation to join the Jet Age after Germany, Great Britain, the United States and the Soviet Union. The flight lasted only 10 minutes and never got about 1000 feet and it was quite clear the Jumo 004 wasn't enough engine for the Triton. 

The third Triton. Note the new lateral intakes and reprofiled cockpit.

The first Paris Air Show after the war took place only three days after the Triton's first flight and the third Triton airframe minus its engine was displayed. Not happy with the reliability of the Jumo 004 engine, Servanty's team switched to Rolls Royce Derwent engine, the same engine that powered the Gloster Meteor fighter. They then switched again to a more powerful Rolls Royce Nene engine which was the engine of the De Havilland Vampire fighter. The French company Hispano Suiza had just gotten a license to build the Nene for the French Air Force's order of Vampire fighters. Because of the increased mass air flow of the Nene engine, the third and fourth Triton featured lateral intakes and improvements to cockpit visibility. In addition, ejection seats designed by Heinkel were installed. The fourth Triton flew first on 19 March 1948 with the third Triton flying for the first time on 4 April 1950. In fact, the fifth Triton flew before the third Triton on 23 May 1949. The sixth airframe was the static test article. Of the last three flying Tritons, it was the fourth one that flew the most as the third and fifth airframes only made a few flights before getting grounded for mechanical issues. The airframe summary is as follows: 

• Triton 01: Prototype, Jumo 004 powered. Eight test flights. Retired in November 1947.
• Triton 02: Identical to prototype, but never flown as it was set aside for the French Rateau engine which never became available for use. 
• Triton 03: Modified for the Nene turbojet. Only two test flights before getting grounded for mechanical issues. It can be seen today at the French aerospace museum at Le Bourget. 
• Triton 04: Most successful one of the group. 189 test flights. Final flight in November 1950.
• Triton 05: Damaged due to a forced landing after only eight test flights. 
• Triton 06: Static test article not intended to fly. 

While modest in performance compared to the jet aircraft of the late 1940s, the Triton gave French industry its first jet experience and many of the prominent test pilots of the time got their first jet time on the Triton given it's trainer layout. Not a bad accomplishment for an aircraft that was designed in secret not out of security but out of fear of the Nazi regime. Lucien Servanty stayed on with Sud-Ouest which became Sud Aviation in 1957. He rose to engineering prominence at Sud Aviation and headed the French design team for the Concorde before his death in Toulouse in 1973. 

Source: X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974 by Tony Buttler and Jean-Louis Delezenne. Hikoki Publications, 2012, pp 22-26. Photos: Wikipedia, Walter Van Tilborg Collection. 

The Early Days of Airbus Industrie and How the A300 Got Its Name

Roger Béteille, father of Airbus Industrie

The roots of the formation of Airbus Industrie are tied more to the abilities of one man more than any other individual in the early history of the Airbus consortium- Roger Béteille. A graduate of the prestigious École Polytechnique, he was the technical director of Sud-Aviation in the mid-1960s. Sud-Aviation produced the Caravelle and it was Béteille who was the director of the jet's flight test program. In postwar Europe prior to the formation of Airbus, the Caravelle was only one of two commercial aircraft programs to make money (the other being the BAC One-Eleven). He also worked closely with Hawker Siddeley on the Concorde program- this was an experience that unique among the French technocrats of the time, gave him a close working relationship and mutual respect of the British aerospace establishment. In the aerospace industry of France in those days, someone of Béteille's skills was unique given his flawless English, the respect afforded by the British engineering staff at Hawker, and his political skills in working with several European nations in the course of his career at Sud-Aviation. 

In the summer of 1966 there were three proposed commercial aviation projects that were commanding the attention of the European industry. The first one was the BAC Two-Eleven, a successor to the successful BAC One-Eleven. That summer BAC was riding high on the success of the One-Eleven which at the time was one of Britain's most successful and profitable aerospace programs. But it was already facing significant competition from the Douglas DC-9 and the Boeing 737 and BAC had been lobbying the British government for support to launch the Two-Eleven which would have been powered by a new engine Rolls-Royce was developing, the RB.211, that would also go to the Lockheed Tristar. The Two-Eleven was a larger development of the One-Eleven that for the most part, was intended to get British European Airways (BEA) to drop its interest in the Boeing 727-200. The problem with BAC was that it was heavily committed to the Concorde program and had little financial resources to devote to the further developing the Two-Eleven which is why they were keen on approximately $100 million in launch funding from the British government. 

Hawker-Breguet-Nord HBN 100

In the previous year (1965), the head of Breguet Aviation, Henri Ziegler (who later became Airbus's first president) had inked an agreement with fellow French firm Nord Aviation and Hawker Siddeley in the UK to jointly work on a widebody twin called the HBN 100 that was largely the product of Hawker's engineers at their Hatfield facility. The HBN 100 was to have two variants, one with a passenger capacity for 225 and a stretched one with a capacity for 260. The planned engines were to be either the Pratt & Whitney JT9D that was under development at the time for the Boeing 747 or the Rolls Royce RB.178 which was a three-shaft demonstrator engine called the "Super Conway" that eventually led to the RB.211. At the same time as the HBN 100, Sud-Aviation (Roger Béteille's firm) was working the Galion which was very similar in layout, appearance and size to the HBN 100. The Sud-Aviation Galion evolved from what had started out as an enlarged Caravelle. 

Sud Aviation Galion

In 1966 Béteille invited his friends from Hawker Siddeley to Sud Aviation's facility in Toulouse to see if the design work on the HBN 100 and the Galion might be aligned towards a common joint project. That invitation for Arthur Howes, who headed the Hawker team, to come to Toulouse is what gave birth to the Airbus. It soon become a joint program with engineers from all the involved companies shuttling down to Toulouse as needed as the designs of the Galion and the HBN 100 were more closely aligned. That December at a meeting in London, France, Great Britain, and West Germany- I'll soon get to how the Germans entered the picture- decided that a single consortium would build a widebody twin. At time time, Concorde had two production lines- one in France and one in the UK, and on top of the financial costs of the program, the duplication of effort was something Roger Béteille wished to avoid so that an attractively priced aircraft could be offered to the world's airlines. It was agreed that in exchange for Rolls Royce developing a new engine for their design, the Sud Aviation Galion would form the baseline design to work from with the HBN 100 being sidelined. 

It was obvious at the time that any joint effort would be spearheaded by Britain and France, the only Western European nations at the time that had the industrial capacity for large commercial aircraft design and production. But the West Germans were keeping an eye on the developments and the use of the name "Airbus" in reference to the nascent project actually came from them. Even though it was twenty years after the end of World War II, the German aircraft industry was still in shambles. Many legendary names like Messerschmitt and Dornier were still around, but even those entities were hollow shells of their former selves. What engineering staff hadn't left Germany after the war debated the future of their industry and decided the future lay in collaboration on a civil aircraft project. The year before Roger Béteille invited the British to meet in Toulouse, seven German aircraft companies (ATG Siebelwerke, Bolkow, Dornier, Flugzeug-union Sud, Hamburger Flugzeugbau, Messerschimitt and VFW) formed Studiengruppe Airbus (the Airbus Study Group) to determine what sort of aircraft the future airline market would need. It was this grouping of German companies that contributed the Airbus name to the young enterprise. It was at the following year's Farnborough Air Show that German participation was formalized. Up to that point, the Germans had been working on their own but it was decided that what the French and British had come up with baselined off the Sud Aviation Galion was a suitable candidate for their contribution to the effort. Officially becoming Airbus, each nation decided that one company from each nation would take the lead for that nation's contribution. Hawker Siddeley would lead the British contribution, Sud Aviation would lead the French contribution and the German Airbus Study Group was reorganized into a formal consortium of their own, Airbus AG, to lead the German contribution. 

But what to name this aircraft? Arthur Howes of Hawker Siddeley was partial to the name "Obelix" which was the giant in the Asterix series of comic books popular in those days. It was apparent, though, that the name had to be something that was essentially neutral to British, French and German interests. One evening at a dinner in Sud Aviation's Paris headquarters the upper level of management at Sud Aviation asked why a name for the aircraft hadn't been found yet. Different ideas were punted about before Howes himself spoke up as a joke and said "I propose we call it the HSA 300" and the room laughed as "HSA" was the initials of Hawker Siddeley Aviation. But Howes continued "H- Hawker Siddeley, S- Sud Aviation, A- Airbus, and 300 because it's a nice round number." As everyone enjoyed Howes' joke, it suddenly donned on him- why don't we call it the A300? 300 is still a nice round number closest to the proposed design's seating capacity and if "A" was used, the aircraft would always appear before Boeing in any alphabetical listing. Howes idea proved popular and the nascent enterprise's new design would be marketed as the Airbus A300.

Further reading on this blog on the early history of Airbus:

How American Airlines Shaped the A300
How Rolls Royce Scuttled British Participation in Airbus

Related reading:
American Airlines Picks the DC-10 (American's pick of the DC-10 is intertwined with the early history of Airbus)

Source: Close to the Sun: How Airbus Challenged America's Domination of the Skies by Stephen Aris. Aurum Press, 2002, pp 6-11. Images: Wikipedia, Air International