The Payen Pa 49 was a tiny experimental aircraft and the brainchild of aviation extraordinaire Roland Payen, who hoped it could become the first-ever delta-winged jet to be flown in France.
Lilliputian in dimensions and power and rather underwhelming at first, no one, not even its talented creator, could have predicted that one of its features would eventually end up as an essential component in a spacecraft that would dwarf it in every conceivable aspect.
As a misbehaving schoolboy throwing paper darts at his friends, Roland Payen first noticed the excellent gliding characteristics of his chosen projectile, and how its simple sleek shape looked nothing like the aeroplanes being produced at the time.
Opting to become an aviation engineer, shortly after his 19th birthday in 1928 Payen built his first flying contraption in the style of the paper missiles of his youth, inventing a single-seated glider reminiscent of contemporary German Zögling design.
By the 1930s Payen was busily experimenting with other ideas and collaborating with other engineers on a variety of novel designs such as the Bratu 220, a transport craft powered by three engines with enough space to accommodate 10 passengers, the RAP-40 Boby-Plane, a powered touring aircraft with tandem wings inspired by the Darmstadt D.18., and finally a series of Sauvage-Payen prototypes such as the SP.240 ambulance plane and the SP. 220 light fighter, unusual for their ‘gothic’ or ‘ogvic’ wings which in planform resembled a Middle Age gothic arch.
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Payen’s career thereafter was marked by that same fervent desire to innovate, and as a result, his planes were often built with unorthodox features that inevitably aimed in some way to break preexisting conventions.
In 1934 one of his first solo efforts was the Pa.100, regarded as so bizarre and futuristic with its unconventional short-span delta wing placed well ahead of the cockpit, that it would play a starring role in a 1935 edition of the science-fiction magazine Bill Barnes, Air Adventurer.
In addition, in 1935 after proposing that his latest aircraft could be solely powered by a newly invented ram-jet engine, Payen’s benefactor Monsieur Poisson, a silk manufacturer from Lyon, was told by the French Air Ministry that he was a fool if he thought that a plane could be operated without a propellor.
Payen was ahead of his time on many other occasions as well, such as in 1942 when he drew up blueprints for the Pa.42/5, a very strange-looking plane that featured a detachable motorized cargo fuselage and could be driven on highways in the same fashion as a truck. Only 6 years later the same configuration was patented by the chief engineer of Fairchild Armand J. Thieblot for his XC-120 Pack Plane.
But Payen’s most influential, and unexpected, contribution would come to a couple of years after the end of World War Two and would originate from his Pa.48/3 Mars, just one of the many outlandish combat craft he devised as the French aeronautical industry experienced a postwar renaissance.
The Pa.48/3 Mars was anticipated to have a maximum take-off weight of 12,110 pounds, a maximum speed of 634 miles per hour, and a combat radius of 1,300 miles. Payen had big plans for it, for if accepted by the French Air Ministry, who were looking for a new interceptor, and then taken for a spin, it would become France’s first jet-powered delta-winged aircraft to fly.
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Propelled by a 5101 pound Hispano Suiza Nene turbojet, the Pa.48/3 Mars was a tailless interceptor with a two-spar wing that was sweptback to 60 degrees, and was furnished with an unusual centerline undercarriage with outrigger wheels which retracted into the wing.
Mounted at the nose with 4 15 mm Hispano-Suiza machine guns, the composition of the craft was less conventional, and was to have a welded steel tube fuselage covered with metal sheet skin, while the wing would be entirely made out of wood.
When the Pa.48/3 Mars failed to generate any interest it became just another in the spate of rejections that Payen was receiving at this troubling stage of his career, yet he remained unperturbed. Eager to prove to the world that his designs were sound, he began assimilating many of the innovations of the Mars into his next self-funded project: the Payen Pa.49.
Payen Pa 49
Originally known as the Pa 49 Payen Delta Jet and later named ‘Katy’ after his daughter, the Pa 49 was essentially a scaled-down version of the Pa.48/3 Mars and was extremely small with a length of just 5.10 meters and a height of 2.50 meters.
Instead of having a mix of different surfaces like its predecessor, the Pa 49 was built entirely out of wood, while its wings had a sweep angle on the leading edge of 55 degrees, a trailing edge of 27 degrees, were controlled by outboard ailerons and elevators situated in the inner segment and were blended into the fuselage.
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The air intakes provided for its single Palas turbojet, which only possessed a tiny 331 pounds of thrust giving it a maximum speed of 310 miles per hour and a range of 280 miles, were located in the wing root leading edge where a fin swept at an angle of 78 degrees was placed, just behind a very cramped cockpit reminiscent of the drivers bay of a Formula One racing car.
Initially, the Pa 49 sported a low bicycle undercarriage with skids at the wingtips, but by the time it had undertaken its maiden flight, this had been changed to a more traditional fixed tricycle undercarriage.
A scale model of the Payen Pa 49 was first placed inside ONERA’s large wind tunnel facility at Chalais-Meudon, where a combination of actual performance data and the effects of faulty streamlined masts supporting the airframe provided unsatisfactory results.
Nevertheless, with the ever-optimistic Payen attributing most of the blame to broken testing equipment, the project continued undisturbed, and by November 1953 the now fully assembled Pa 49 was being subjected to a string of small-scale taxi assessments at Melun-Villaroche.
On December 16th 1953 the Pa 49 made a short practice hop in preparation for its maiden flight, but before it was even allowed to take to the skies properly test pilot Tony Oshenbein was ordered to don a regulation crash helmet by aviation authorities, consequently delaying the maiden voyage until January 17th 1954.
Unfortunately for Payen, this critical setback meant that his design would not be lauded as France’s first jet-powered delta-wing to fly, for only two days before the Nord 1402 Gerfaut I had already beaten him to it.
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Nevertheless, Payen directed his energy to the task at hand and presiding over the flight data supplied by a test log of around 10 hours discovered that it was a distinctively mediocre performer, particularly at low speeds. There was a glimmer of promise though, for he also concluded that a more powerful engine and more aerodynamically efficient components could improve results.
The Pa 49 was next transferred to the Centre d’Essais en Vol or ‘CEV’ at Bretigny for trials in April 1954 before being displayed at the Le Bourget Salon in 1955 to thousands of curious onlookers fascinated by its petite dimensions.
In late May 1957, the Pa 49 was exhibited to a global audience at the Le Bourget Paris Air Show, by which time its undercarriage had been changed for a second time into a spatted configuration. It was here that it won the admiration of an Italian journalist and pilot called Vico Rosaspina, who asked Payen for permission to fly it to his home in northern Italy to show off.
Despite provision being made for the Pa 49 to be installed with a 130-litre Imp gal belly fuel tank to undertake the journey, the Italian jaunt would sadly never materialize.
A Galactic Legacy
Over several years the Pa 49 underwent nearly 300 evaluations comprising some 180 flying hours, which in addition to sketching out a more accurate picture of its performance and flight profile also revealed the advantages of its ‘crocodile jaw’ split-rudder configuration used for yaw and airspeed control, which had been added to it during its time at the CEV as a way of ensuring it could reach the angle of attack necessary to achieve maximum lift off on landing.
The engineering team behind the Concorde supersonic airliner would later conduct their own lengthy experiments with the crocodile jaw, although it was never incorporated into the final product. It was however adopted by the Rockwell International Corporation, who used Payen’s trailblazing vertical stabilizer in its fleet of delta-winged Space Shuttle Orbiters.
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Nowadays the compact Payen Pa 49 can be found at the Musée de l’Air et de l’Espace inside the Le Bourget Airport in Paris which was curated for a time by Roland Payen himself, who donated his creation to the collection 1976.
- Crew: 1
- Length: 5.10 m (16 ft 9 in)
- Wingspan: 5.16 m (16 ft 11 in)
- Height: 2.50 m (8 ft 2 in)
- Empty weight: 457 kg (1,008 lb)
- Gross weight: 650 kg (1,433 lb)
- Powerplant: 1 × Turbomeca Palas centrifugal-flow turbojet, 1.5 kN (330 lbf) thrust
- Maximum speed: 500 km/h (310 mph, 270 kn)
- Range: 450 km (280 mi, 240 nmi)
- Service ceiling: 8,500 m (27,900 ft)
- Rate of climb: 5.8 m/s (1,140 ft/min) initial