10 Reasons the Sud Aviation Caravelle Jetliner is Fantastic
Unbearably beautiful, featuring a wealth of innovations and capable of recording gypsy jazz singles in flight, there are many reasons why the Caravelle was a technological tour de force that inspired love in those that came close to the French jetliner. We take a jet-age saunter through the boulevard of aeronautical nostalgia to meet an incredible (and all too frequently overlooked) masterpiece to take a look at just 10 fantastic things about the Caravelle.
10. X-210 Tri-Atar
By the end of the War, the French aviation industry had been reduced to nothing. Its factories, in the hands of the Germans, had been priority targets for the Allied bombers. The French aeronautical industry had lost the international lead it had held since the very beginning of aviation, and had seemingly lost everything else. Its renaissance was close to a miracle and was the result of extremely confident and clear thinking. This assertiveness led to the superlative Mirage series in the military realm, and civil ambitions were no less hopeful. In 1951, the General Secretariat for Civil and Commercial Aviation (SGACC) launched an extremely ambitious competition among French aircraft manufacturers to develop a medium-haul aircraft. This new airliner was to connect the main European destinations, with 55 to 65 passengers and one ton of freight, on routes of more than 2000 km, flying at a minimum cruising speed of 600 km/h at an altitude of 7,500 meters, and be able to take off in less than 1800 metres for a maximum landing distance of 1125 metres. Despite the technical and technological backwardness of France at the time, the vast majority of response proposals made the bold choice of skipping the turboprop stage and opting instead for the use of turbojets, a new and risky technology. This was a daring choice, as only the United Kingdom had developed (somewhat hastily) a commercial jet aircraft, several years ahead of the USA and the Soviet Union*.
The SNCASE company’s answer to these specifications was the X-210 Tri-Atar. It was planned, as its name indicates, to be an aircraft powered by three SNECMA Atar turbojet engines with an arrangement that would later feature on the Boeing 727: two turbojets in nacelles at the rear of the fuselage and a third one integrated into the fuselage. However, there were delays in the development of these Atar engines and when Rolls-Royce announced that its new, more powerful version of the Avon turbojet engine was available for civil aircraft under development SNCASE paid close attention. Thanks to the power gain the new engine had over the Atar, a new aircraft could easily make do with only two engines. This new configuration, with only two engines placed far from most of the cabin would be far quieter than any rivals. It would certainly offer a far quieter experience for travellers than rivals like the British Comet and Soviet Tu-104 with their engines buried into the inner section of the wing. In 1953, shortly after the tri-jet concept had become a bi-jet, it was definitively renamed SE-210 Caravelle, and the appearance we know today was finalised. The name refers to the caravel ships of the 15th century, which by dint of their speed and strength opened the world to European exploration.
Many radical technical solutions put the aircraft at the forefront of technology. For example, the Caravelle’s designers opted for hydraulic servos whereas the Boeing 707, Tu-104 and D.H. Comet used entirely mechanical flight controls operated by a system of cables running through the fuselage and wings. The Caravelle was the first commercial aircraft certified to fly with hydraulic servos. Piloting the Caravelle was thus far less tiring than for its rivals, and it had the most comfortable controls of any civil aircraft of the time.
9. Triangular portholes
Caravelle is a unique aircraft because of its many small eccentricities. One of the most obvious, at first glance, is surely the strange shape of its windows: triangles with widely rounded-off corners. Although some may think that they result from a study of pressurization carried out after the various accidents of the English D.H. Comet (the square shape of its portholes being one of the main causes of the accidents), the triangular shape was actually decided well before the complete analysis of the causes of the crashes had been concluded. Indeed, the final report of the Cohen C1 committee, in charge of understanding the disasters, gave its conclusions on November 24, 1954: the first Caravelle prototype registered F-WHH, had been in production since March 1953.
The truth about this surprising shape comes from a very thorough study on the visual comfort of the passenger: the section was narrow and partly high to limit the risks of glare due to the sun, and the lower wider part gave a clearer view down, allowing the travellers to more easily admire the often epic landscape visible from 10000 metres in the sky. This formula obviously passed numerous pressurization tests, just like the rest of the Caravelle airframe, which was immersed in a large water chamber to study the weaknesses and possible premature fatigue of the metal. The iconic windows become omnipresent in the 1960s advertising campaigns of the 60s of Sud-Aviation and the airlines operating the SE-210. The campaigns were so successful that the general public learnt to associate the image of triangular windows with the Caravelle.
Unfortunately, this shape, although innovative, was something of a design cul de sac. It can nevertheless be found on the private jet Rockwell Sabreliner 65 which, in the broad lines, takes again the general configuration of Caravelle.
8. Land anywhere
It was all very well for France to develop the first medium-haul jet, but were airports around the world ready to receive it? For an aircraft of this category, it is imperative to be able to land on as many runways as possible, everywhere in the world, and not just at international airports. The problem was the length of runways. At that time, the most modern four-engine aircraft with their greed for long strips of concrete could enjoy 170 sufficiently long runways in the United States of America. But on how many European, African or South American runways could such a plane land? This is where the genius of Sud Aviation comes into play again. The Caravelle was designed to land on all runways built for the earlier DC-4 era, and even shorter ones if necessary. For the latter, a tail parachute – until then the reserve of military aircraft – could be deployed, reducing the landing distance considerably (this would also feature on the Tu-104).
This is how Caravelle became the first commercial jet to land at the airports of Buenos Aires, São Paulo, Porto Alegre, Belem, Montevideo and many others. But another problem arose at many airports still suitable for traditional propeller planes: there was no infrastructure in place for boarding and disembarking passengers from a jet. Once again, this problem was quickly solved, Sud-Aviation equipped its aircraft with an elegant retractable staircase located in the tail of the aircraft, allowing passengers to board and disembark the aircraft anywhere without infrastructure.
7. A gliding airliner
On April 15, 1959, Air France carried out a novel publicity event to promote the safety of the new aircraft. A Caravelle deliberately glid, without propulsion, between Paris and Dijon in France, a distance of more than 262 kilometres (163 miles). The first production aircraft (F-BHRA) Alsace was chosen. The aeroplane took off with its two engines at 13:42 from Orly airport near Paris piloted by Marcel Guibert and René Duguet. The aircraft climbed to 13200 m and reached speed of 665 km/h above Paris, at 14.46, the engines spooled down. Above the capital, the thrust of the engines was now cut.
The Alsace then turned towards Dijon, 265 km away. The aircrew experienced an eerie silence across the flight only disturbed by the sound of wind on the windshield. After 46 minutes of gliding, the plane finally reached Dijon at 3:32 pm, at an altitude of 1600 m. After its descent to the arrival airport, the throttle was only turned on for the last moments of the final approach, in order to guarantee the safety of the passengers.
“Passengers?” You may ask. Yes indeed, remarkably the aircraft was loaded with 35 passengers and journalists in addition to the crew and two flight attendants for this somewhat hair-raising flight!
Shortly after, on October 11, 1959, the Brazilian airline VARIG seeking to justify to the public the purchase of a jet produced in France and not on the American continent, repeated the feat of a gliding flight in the same conditions between the airports of Passo Fundo and Ossario, almost 327 km away, thus pushing back the record of Air France, and, demonstrating once again the incredible gliding characteristics of the Caravelle. The aeroplane had a glide ratio of over 22, better than many pre-war competition gliders. The glide ratio of an aircraft is the distance of forward travel divided by the altitude lost in that distance; for comparison, the tiny-winged F-104 has a glide ratio of 5. The Caravelle’s, at 22, is almost the same as the famously glider-like U-2 spyplane!
These feats were the only demonstrations of the gliding capabilities of an airliner of such importance (except for flight accidents such as Air Transat flight 236). This was made possible thanks to the incredibly efficient wings of the aircraft, which free of any engine, offered a very pure aerodynamic form.
6. A recording studio in the stratosphere
In 1959, Air France set up another world first to promote the plane’s superiority over its competitors: in this case, it was no longer a question of its gliding abilities, but of celebrating the quiet cabin. Whereas competitors had engines in or under the wings, noisily close to most areas of the cabin, the Caravelle’s two engines were neatly tucked away in nacelles at the rear end of the aircraft. It was said that the noisiest seat on board the Caravelle was only as noisy as the quietest seat in the quietest rival airliner.
To demonstrate this guitarist and singer Sacha Distel, accompanied by his orchestra, took a trip aboard the Caravelle III Alsace to record a single inside the aircraft during a dedicated flight on 17 April 1959. In addition to musical instruments – including a piano weighing over 200 kg – a complete recording studio was installed on board. Once the plane was at an altitude of 10500 metres the recording began, made possible by the extremely quiet cabin.
Sacha Distel chose to perform a cover of the jazz guitarist Django Reinhardt’s instrumental ‘Nuages’ (cloud) a fitting title. The recording, in the form of a single called “Altitude 10 500 m”, was released by the Philips record company in the same year, 1959.
5. Caravelle to the Americas: First JFK jet
After a promotional tour of both American continents in 1957, Brazil’s leading airline VARIG was utterly seduced and placed an order with Sud-Aviation. VARIG originally planned to use both Boeing 707s and Caravelles on its network, the former for overseas routes – and the Caravelles for domestic travel. While Boeing fell behind in the production and delivery of its many 707s, the first VARIG Caravelle was delivered to Brazil on 24 September 1959. For its introduction, VARIG chose to operate the Caravelle on its prestigious Rio de Janeiro – New York service. VARIG was proud of its new jet and still lacking the promised 707s. With this route, VARIG became the first airline to operate a jet from Idlewild Airport (now known as John F. Kennedy Airport) in New York, making the Caravelle the first jetliner to operate on both American continents.
On 25 February 1960, United Airlines, then one of the world’s largest airlines, signed a contract for 20 Caravelles and took 20 options, for a contract worth about $65 million (equivalent to over $635 in 2022 dollars). A huge success for Sud-Aviation. Few European aircraft had been successful in exporting to the US at that time; it would not be until the Falcons and Airbus that such successes would be seen again. The American company requested a number of small modifications to the airframe, including the enlargement of the cockpit windscreen and the addition of thrust reversers and more powerful brakes, the resultant variant was known as the Type VI-R Caravelle. The first United Airlines Type VI-R, christened ‘Ville de Toulouse‘, was received on 10 June 1961 and scheduled flights began on 14 July, Bastille Day.
4. Tough as hell
Sometimes accidents highlight theoretical but normally unprovable technical characteristics of an aircraft. The robustness of the Caravelle’s airframe and its ability to withstand collisions were proven in a spectacular accident early in the aircraft’s operating career. On 19 May 1960, at 9.46 am, a small SV 4-C Stampe biplane, registration number F-BDEV, owned by the Club aéronautique universitaire de Chelles-les-Pins and piloted by Mr René Fabbro, collided in mid-air with a Caravelle belonging to Air Algérie departing from Orly. The impact completely destroyed the small plane, which was partially stuck in the Caravelle, killing its pilot on the spot. The propeller tore the roof of the airliner over several metres, severing the back antenna in the process, killing one passenger and injuring several others. Despite extensive structural damage and a now disabled radio, the Caravelle managed to land safely at Orly airport. The damage would, in similar circumstances, have caused the loss of many comparable airliners, but the robustness of the Caravelle and its airframe demonstrated the care that Sud-Aviation had taken with its aircraft. The investigation will reveal that the Stampe was in a restricted area and that the pilot simply did not see the Caravelle coming.
3. First autopilot
The Caravelle, as you will have seen from the various points already highlighted, was a safe aircraft, especially if you compare its accident rate to its counterparts, the first generation commercial jets. The aircraft was already superb, but there was a desire to make the aircraft even more dependable, as punctual as a train. One way to do this was to ensure it could operate in weather conditions that would hinder all of its rivals. As early as 1962, the first Caravelle prototype, F-WHHH, was modified and carried out the first automatic landing tests. A military system comprising a Lear Siegler autopilot was installed and coupled to a TRT radio altimeter. This was the first time that a civilian aircraft had been fitted with such a system. (A British system developed by the Smith Company was also tested but was found to be too complicated.)
When the Caravelle entered the Air Inter fleet, it was equipped with this brand new Sud-Lear system called ‘Autoland’. This system made Air Inter’s fleet of Caravelles the first airliners in the world certified to make Phase III approaches, with 50 feet of visibility and 150 meters of runway visibility. It was not until 9 January 1969 that one of these aircraft, filled with fifty-six passengers, left Lyon and landed at Orly fully automatically in the fog, without pilot intervention. On board, Captain Pierre Larribiere had just achieved a world first: from now on, planes would no longer be afraid of fog.
2. The SE-210 Vomit Comet
Parabolic flights reproduce gravity-free conditions and involve an aircraft flying upwards and downwards in arcs interspersed with level flying. They enable research in microgravity conditions without the expense of spaceflight. So violent are the flights that they are informally known as ‘vomit comets’. At the end of the 1980s, France sought to extend its independence from the USA for parabolic flight. Indeed, for any training or experiment in microgravity, Europeans were dependent on NASA flights, which gave priority to its own activities. It was under the impetus of French astronauts Jean-François Clervoy and Jean-Pierre Haigneré that the Centre national d’études spatiales (CNES) and the flight test centre (CEV) decided to convert a Caravelle for microgravity flights. A Caravelle of type VI R produced in 1968 and which had enjoyed a successful (but relatively boring) career as an airliner in Luxembourg returned to France in 1989 under the registration F-ZACQ.
It was assigned to the Flight Test Centre and became the famous Caravelle Zero-G, after a general refit. CNES entrusted the marketing and management of this new sector to its subsidiary Novespace. Thanks to this, the Europeans gained their independence and Caravelle Zero-G allowed the first scientific parabolic flight campaigns from 1989 onwards. Caravelle Zero-G stopped flying in 1995, after six years at the CEV and a busy career before its conversion. It was this aircraft that made it possible to carry out more than 40 scientific flight campaigns, accumulating more than 4000 parabolas for a total of 24 hours of weightlessness. Thanks to the Caravelle, European was able to carry out independent research without dependence on NASA. It was replaced by another European type, the Airbus A300 Zero-G.
1. After Caravelle, Super-Caravelle: The Mother of Concorde
After such an obvious technical success, France, having gained confidence, decided to embark on the adventure of supersonic commercial transport and started the Super Caravelle project in the late 1950s. Numerous exotic projects were then explored including flying wings, nuclear aircraft but most were far too ambitious.
Sud Aviation was then asked to repeat the Caravelle’s success with the support of Dassault, with its vast experience of the science of supersonic flight. Dassault and Sud Aviation presented their work and a model of the project in 1961 at the Paris Air Show.
The conceptual aircraft was a medium-haul design with delta ogival wing with accommodation for 70 passengers over distances of 2,000 to 3,000 km at speeds of between Mach 2 and Mach 2.5. The aircraft was promoted as a winning mixture of the Caravelle and the Mirage IV.
At that time, the British were also developing a supersonic airliner with a rather similar project, the Bristol 223. The French and British projects were already well advanced, but it was the realisation and the enormous costs of developing a prototype that led the two countries to embark on a collaboration, both nations seeking above all to counter American market dominance. So in 1962 Super Caravelle merged with the Bristol 223 to create the famous and fabulous Concorde.
Concorde retained the look of the Super Caravelle, as well as its wonderful “ogival” wing.
(The name “Super Caravelle” will nevertheless be reused for longer models of the SE.210)
*Leaving aside abortive Canada’s C102 Jetliner
Brilliant article, about a brilliant airplane! Bravo! A lot of amazing facts and a really impeccable choice of photos. One thing intrigues me: the glide ratio of 22. Do you have a reference for this? It seems unusually high. I thought most 1st and 2nd generation jets could barely achieve an L/D of 15-17 and that the best L/D today belongs to the B787 and A350 in the vicinity of 20-21. I am assuming that the idling engines of the Caravelle were probably producing some minimal thrust to achieve 22, but even then, it seems quite high for the level of aerodynamic optimization available at that time.