About

The Sud Caravelle was an early, reasonably-successful narrowbody twin-engine regional-jet produced in france from 1953 until 1972; the early development work (including the building of the two prototypes and initial flight-testing) was done by French manufacturer SNCASE, but mass production (starting in 1958) and entry into service (in 1959) were performed by the larger (but still French) Sud Aviation (formed in 1956 by a mass merger of several aviation companies based in southern France, including SNCASE). It was the third jetliner to fly (following the de-havilland-comet and the Avro Canada Jetliner, the latter of which never entered service), and the fourth to enter service (after the Comet, Tupolev tu-104, and boeing-707); of these, it was the first-ever regional jet, the first twinjet airliner to fly, and the first Western twinjet to enter revenue service (the first twinjet airliner of any description to enter airline service having been the Tu-104, which entered service well before the Caravelle, despite its later first flight).

The Caravelle’s genesis began with an October 1951 request for proposals issued by the French government, calling for an advanced, medium-range, medium-size, reasonably-fast airliner; the speed requirements quickly caused the many responding manufacturers to settle on turbojet engines (with only a few holdouts proposing turboprop-powered aircraft), but the anemic thrust of the then-available turbojets required either the use of three or more engines (even though two would have been the optimal number had a sufficiently-powerful turbojet existed) or the use of small auxiliary engines which would run only to assist with takeoff and then be shut down for the rest of the flight (contributing only weight and drag from then on). SNCASE went the three-engine route, necessitating that one of the engines be placed along the aircraft’s midline (and, thus, in the tail); to simplify things, they decided to put the two remaining engines on the tail as well, rather than hanging from (or buried in) the wing. As the real estate on the sides of the tail where the horizontal-stabilizers would normally be mounted was taken up by engines, the designers moved the horizontal stabilizers upwards, onto the sides of the vertical-stabilizer, giving the design (known as the X-210) a cruciform-tail (something fairly common on the smaller private-jets, but decidedly unusual for an airliner).

Fortunately, jet-engine technology advanced very quickly in those early days, quickly rendering the X-210’s third engine unnecessary. It was thus deleted, while the other two were left on the tail to avoid the additional design work of moving them to the wings; this made the aircraft slightly heavier, as a wing-mounted engine, paradoxically, allows the wing structure to be made lighter (as the lift produced by the wings bends them upwards during flight, requiring that the wing be stiffened [with the attendant weight penalty] to avoid excessive, fatigue-promoting flapping, and the weight of wing-mounted engines helps to counteract this upward bending, reducing the amount [and weight] of stiffening needed), but greatly decreased cabin noise levels (as the loud parts of the engines were now further from, and behind, the inhabited parts of the cabin) and also (as the engines’ placement on the sides of the tail left them considerably higher above the ground than would have been the case for wing-mounted engines - especially on a smaller airliner like the Caravelle, which doesn’t have that much space between the wing and the ground to begin with) reduced their susceptibility to foreign-object-damage from runway debris. (The noise and damage-susceptibility advantages would cause most other regional jets to follow the Caravelle’s lead with tail-mounted engines; only very recently have regional jets with wing-mounted engines, such as the airbus-a220, hit the mass market.)

The now-two-engined design, which graduated from the X-210 to the SE-210 designation (the SE standing for Sud-Est [French for “Southeast”, and part of SNCASE’s long name], not for Stack Exchange) and gained the “Caravelle” moniker (French for “caravel”, a type of old-timey sailing ship) somewhere around this time, was otherwise unremarkable, apart from its cockpit having an unusual arrangement of windows (inherited directly from the Comet, SNCASE having licenced the nose and cockpit arrangement of the latter airliner from de Havilland), its cabin windows having a distinctive rounded-triangle shape (which reduced the size of the window openings, thereby increasing the structural strength of the pressure hull, without restricting the passengers’ ability to gawp at the scenery below), and its use of a parachute to help it slow down during landing (a thrust-reverser system not yet being available). The first prototype started construction in the summer of 1953, and made its first flight on 27 May 1955, followed by Caravelle number two three weeks shy of a year later (on 6 May 1956). Extensive testing followed, and the first orders (from, of course, Air France) came in in 1956, with proving flights for said carrier in progress by the end of the year. After not quite four long years of flight testing and proving flights, the Caravelle finally entered revenue service on 26 April 1959 with, not Air France, but, rather, the Scandinavian Airlines System (SAS) (although Air France quickly followed suit with their own Caravelles).

As the Caravelle was the only regional jet in town for several years, and was faster (jets tend to do that), quieter (for the occupants, at least; those on the ground probably thought differently), and sexier (it’s a jet!) than its propeller-powered competitors (such as the vickers-viscount and convair-240-family), sales were brisk, helped by the rapid-fire introduction of new and improved Caravelle variants in those early years. Following the 1965 service debut of the Douglas dc-9-family, the first second-generation regional jet, Caravelle sales tailed off, but they continued to be produced and sold (albeit in ever-decreasing numbers) until 1972, with the final tally being 280 production aircraft, plus the two prototypes, for a grand total of 282.

These 280 production aircraft belonged to eleven different variants (although not all of these were mass-produced), which can, for convenience, be grouped into three main categories based on what engines they used:

Avon-powered Caravelles

These variants were powered, as were both prototypes, by the Rolls-Royce Avon turbojet, the same engine used on the later versions of the Comet. All were 32.01 meters (105 feet) long, and could carry up to 80 passengers. The vast majority of all production Caravelles built - 219 - fall into this category.

• The Caravelle I, which took to the air on 14 May 1958, was essentially a production run of the prototypes; it, like the prototypes, was powered by the Mk. 522 version of the Avon. 20 were built.
• The Caravelle IA was a modified Caravelle I equipped with the more powerful Mk. 526 (or 522A) Avon. First flight was on 11 February 1960; 12 were built.
• The development of an even-more-powerful Avon, the Mk. 527 (later evolved into the Mk. 527B), allowed the Caravelle III to take form; it made its first experimental test flight on 30 December 1959 (thus actually beating the Caravelle IA into the air), but did not enter revenue service until April 1960 (with Italian operator Alitalia). 78 Caravelle IIIs were built, and all but one of the 32 Caravelle Is and IAs were also converted to Caravelle III standard (the sole exception being an SAS Caravelle I that had crashed in January 1960 and was thus not available for conversion), making the Caravelle III the single bestselling Caravelle variant.
• Yet another step up in Avon power, with the Mk. 531 (which evolved into the Mk. 531B), produced the Caravelle VI-N (you’d have to ask Sud - or, rather, their ultimate successor, airbus - why they skipped straight from III to VI), with the N standing for Normal, to contrast it with the VI-R (see below). This more capable variant made its first flight on 10 September 1960, and entered service with Belgian flag-carrier Sabena the following January. 53 VI-Ns were built new, plus five aircraft built as Caravelle IIIs and later upgraded to Caravelle VI-N standard.
• The Caravelle VI-R (maiden flight 6 February 1961) was the last Avon-powered Caravelle; the R stands for [thrust] Reversers (the first Caravelle variant so equipped, allowing the deletion of the braking parachute), which were added (among a host of other improvements, such as enlarged and rearranged cockpit windows and a beefed-up braking system) especially for United Airlines, the variant’s launch customer (using it in revenue service from 14 July 1961) and largest single customer (with a fleet of 20), and the first Caravelle operator in the united-states. The reversers were provided as part of the Avon Mk. 533R and 535R engines (the R likewise standing for Reverse thrust), which also offered yet a further increase in thrust (fully 20% more powerful than the Mk. 522 used on the original Caravelles). Unlike the earlier Caravelle variants, which sold almost entirely to airlines based in or near europe, all but seven of the 56 VI-Rs were sold to operators in the Americas and South and Southeast Asia.

CJ805-23-powered Caravelles

These variants, neither of which made it into mass production, were powered by the General Electric CJ805-23 turbofan, an engine better known for its previous use on the late 990 variant of the convair-880; the CJ805-23, unlike almost all other turbofans, is distinctive in having its fan at the rear of the engine (an aft-fan, or “pusher”, configuration), rather than at the front (a front-fan, or “tractor”, configuration). Only one Caravelle was ever built with CJ805-23 engines (plus a second that was converted from an Avon-powered Caravelle), but these aircraft do have the distinction of being the first turbofan-powered Caravelles, and the CJ805-23 of being the most powerful engine ever fitted to a Caravelle.

• The sole Caravelle VII started life as a Caravelle III, but was purchased by General Electric to serve as a CJ805-23-on-Caravelle testbed. After being re-engined with the CJ805-23, the Caravelle VII took to the air on 29 December 1960 for the first-ever flight of a Caravelle under turbofan power, beginning a series of test flights to validate the engine’s performance when attached to a Caravelle.
• The Caravelle 10A, which first flew on 31 August 1962, was to have been the production version of the CJ805-23-powered Caravelle, geared towards the U.S. market. The considerably-more-powerful engines (over a quarter again as much thrust as even the uprated Avons on the VI-R, and fully 53% more powerful than the Avons on the original Caravelle I) allowed the fuselage to be stretched (a first for a Caravelle) to 33.01 m (108’ 4”). Other modifications included better flaps (required for U.S. certification) and the changes to the wing structure to accommodate same, plus an apu (another Caravelle first). Its launch customer (with an order for 20 Caravelle 10As) was to have been Trans World Airlines (TWA), one of the major U.S. airlines, but an acute lack of money on TWA’s part kept the deal from going through before the DC-9 became available (at which point TWA switched its orders to the new Douglas product instead), and no other buyers came forward for the Caravelle 10A.

JT8D-powered Caravelles

These variants were powered by the Pratt & Whitney JT8D front-fan low-bypass turbofan (all using the JT8D-7 version of said engine, unless otherwise noted), becoming the second aircraft type (following the boeing-727) to use what would ultimately become the best-selling low-bypass turbofan - and second-best-selling jet engine of any description - in history. By the time the first JT8D-powered Caravelles were ready, the first second-generation regional jets (such as the DC-9 and bac-one-eleven) were either already on the market or close to it, and these later Caravelle variants sold nowhere near as well as their Avon-powered predecessors, with a total production run of only 60 aircraft; however, the greater efficiency of the JT8D allowed them to hang on longer than the Avon-powered Caravelles, with the last Caravelle in service - only retired in 2005 - having JT8D engines.

• The first JT8D-powered variant (and the first turbofan-powered Caravelle to actually enter service), the Caravelle 10B (based on the CJ805-23-powered Caravelle 10A), initially took flight on 31 August 1964. While the JT8D-7 was significantly less powerful than the CJ805-23, it was quite good enough for the Caravelle 10B to hold onto the 10A’s 105-passenger fuselage stretch (its length would lead to it gaining the “Super Caravelle” nickname); other modifications included an improve high-lift-device system. 22 were built, one of which would become the aforementioned last Caravelle in service.
• The Caravelle 10R instead mated the JT8D to the shorter body of a Caravelle VI-R to produce a higher-performance aircraft (albeit one with, like the VI-R, a capacity of only 80 passengers). Its maiden flight took place on 8 January 1965, and the first of the 20 10Rs built entered service (with Alia, now known as Royal Jordanian) on 31 July of that same year.
• The Caravelle 11R was a 10R stretched to 32.71 m (107’ 4”); it could carry up to 99 passengers, or, alternatively, a mixed load of passengers and cargo (such a dual-purpose aircraft configuration is known as a combi - short for “combination” or “combined” - aircraft), thanks to a cargo door on the left side of the fuselage. The idea of a combi Caravelle actually dated back all the way to the very first prototype, which had a large cargo door to allow for use in such a configuration, but, starting with prototype number two, the combi concept was shelved for over a decade, until the 11R’s first flight (on 21 April 1967). Only six Caravelle 11Rs were built.
• The last and largest Caravelle ever produced was the Caravelle 12 (first flight 12 March 1971), a further stretch of the 10B (to 36.24 m, or 118’ 11”) which could carry up to 140 passengers (albeit at the price of a shorter range); this further stretch (which gave it, like the 10B, the “Super Caravelle” nickname) was possible due to its use of the newer, more powerful JT8D-9 engine. Twelve Caravelle 12s were built and sold in 1971-72 before the Caravelle production line fell silent.

See Wikipedia for more.