The machine that Marcel Leyat built looked exactly like the fuselage of a WWI fighter plane — minus the wings, minus the landing gear, minus everything that had historically stood between a pilot and the ground. Four small wheels underneath. A flat-twin air-cooled engine up front. And bolted directly to the crankshaft, spinning at 1,400 revolutions a minute where the radiator grille of every normal car in France would have been, a wooden airscrew 1.4 metres wide.

It sat right there in front of the driver. Two feet. Maybe less.

You didn’t need goggles to ride in a Hélica, though you’d want them. What you needed was something rarer: the absolute bedrock conviction that nobody within arm’s reach had decided, in a moment of idle curiosity, to reach forward.

Leyat was born in Die, in the Drôme, on 26 March 1885 — a small town wedged into the pre-Alpine south of France where the Drôme river comes down cold from the hills, fast and opaque with glacial melt. His father was a magistrate. The boy grew up with an engine in his head long before engines were ordinary. By 1906, before he had finished his secondary schooling at the Lycée Champollion in Grenoble — where his classmates called him l’homme papillon, the butterfly man, for his jumping experiments — he had already published an aviation article in the Revue de l’Aviation française arguing that a good aeroplane had to behave like a weathervane, orienting naturally into the wind rather than fighting it. Captain Ferdinand Ferber, one of the founding figures of French aviation, read the piece and approved. Leyat was twenty-one.

He entered the École Centrale des Arts et Manufactures in Paris in 1906, ranked 274th of 280 in the entrance concours. Not a triumphant start. He graduated in July 1911, ranked 146th of 216 — a considerable recovery — which tells you something about a man who learned better once he’d found the thing he was actually learning for.

The five-year span between admission and graduation is longer than the standard four, and not without explanation. In 1909 and 1910, Leyat simply left school to go build and fly aircraft near Die. He came back. He finished. But the flying happened first.

The gliders were the beginning of the thing. In 1907 he built a biplane glider he named Le Quand-Même — the Even So, a name carrying the stubbornness of a man who has been told something is impossible and intends to find out himself. Wing area somewhere between 50 and 55 square metres, depending on which of Leyat’s own accounts you favour; the 1912 article gives 50, the later memoir gives 55, and the difference hardly matters now because the glider sank in the Bay of La Seyne during transport before he could fly it. He built two more by 1909. On 23 August of that year — not the 15th, as Leyat himself would misremember nearly seven decades later in an oral history, but the 23rd, per newspaper accounts and a surviving contemporary diary — one of them carried him 200 metres at ten metres of altitude above the hills outside Die. He was twenty-four years old and had no licence, no instructor, and apparently no surplus of imagination about what an unsuccessful flight might involve.

The powered biplanes followed in 1910, Gnôme-engined, tested at Miramas and later at Bétheny, near Reims. When the Fédération Aéronautique Internationale issued him pilot’s brevet No. 364 on 3 February 1911 — validated by the Aéro-Club de France on a Sommer biplane at Mourmelon — it was a credential, not a discovery. He had already been flying his own motorised machines for months. The brevet made it official. The world caught up to Leyat at its own pace.

He was also watching the English Channel that year. On 19 July 1909 — the same day that Hubert Latham ditched his Antoinette monoplane about a mile from the English coast in the first failed Channel crossing attempt — Leyat wrote to Louis Blériot and offered to pilot Blériot’s machine across the water instead. Blériot declined. Six days later, on 25 July, Blériot crossed on his own. The letter is preserved. History, as it reliably does, did not pause for Marcel Leyat.

The Man Before the Car

He completed his studies, worked at the Société Astra des Constructions Aéronautiques from September 1912 building metal seaplanes, and introduced the stepped catamaran float — a design modification for seaplane hulls that improved performance on water. He moved briefly to Nieuport in 1913, where a photograph shows him at the controls of the Nieuport II. Then he left aviation for the road, because the idea that had been quietly running in the background of all his engineering years had finally come forward and demanded attention.

The idea was structurally simple. If you want to move through air, you push against the air. Road vehicles of 1913 fought the road surface through a chain of intermediary hardware — gearbox, clutch, differential, driveshaft, axle — each component adding weight and mechanical losses. Leyat thought this was ridiculous. He had built gliders. He knew about thrust. Why not just bolt a propeller to the front and pull the whole machine forward through the same medium it was already moving through?

In 1913, with his friend Gabriel Espanet and a carpenter named Floëchel, he built the first prototype. Three wheels. A JAP engine. A propeller on the nose. He called it the Hélicocycle, and in December 1913 he registered the trademark. The original filing contains a typographical error — HELIOCOCYCLE — which is the sort of detail that feels appropriate.

The war came and absorbed everything. Leyat served as an artillery officer, was promoted to Captain in 1917, and was detached in August of that year to the Service Technique et Industriel de l’Aéronautique at the specific request of Colonel Émile Dorand. He ran the Service des Hélices — the military propeller division. Walnut, the preferred wood for aircraft propellers, was in short supply; Leyat developed techniques to substitute commoner species without compromising the structural properties that kept propellers from disintegrating at speed. He was demobilised on 31 March 1919, walked out of the army, and returned to his workshop at 27 Quai de Grenelle in the 15th arrondissement of Paris, five minutes from the Eiffel Tower.

By the end of that year he had built six four-wheeled Hélicas with MAG engines and sold them. The production car had arrived.

What the Hélica Was

A wooden airscrew, 1.4 metres in diameter, was bolted directly to the crankshaft. No gearing between engine and propeller. No reduction ratio. The prop spun at 1,200 to 1,400 RPM and dragged the car forward through thrust alone, its slipstream simultaneously cooling the engine so that no radiator was necessary. The body was a plywood monocoque — the museum records call it a carrosserie de forme ichtyoide, a fish-shaped body — curved plywood panels over wooden longerons, the whole thing sealed into a teardrop cross-section that anticipated automotive aerodynamics research that would not enter the mainstream for another decade.

Two occupants sat in tandem, driver ahead of passenger, as in a cockpit. Total weight for the open sport models ran from 225 to 250 kilograms. A contemporary Ford Model T in touring configuration weighed roughly 750. The Hélica was lighter than many motorcycles of the period.

No gearbox. No clutch. No differential. No reverse gear.

To reverse the car, you stopped, climbed out, pushed it backwards by hand, and climbed back in. Given the weight, this was possible. Given the alternatives, it was arguably preferable.

Steering operated through the rear wheels only, by a cable-and-pulley mechanism with no cogs anywhere in the linkage. The driver turned the wheel; cables pulled; the rear axle pivoted. Period film footage from 1924 survives. In it the inside rear wheel lifts off the road surface during corners. This is not a fault captured on camera. This is the designed behaviour of the chassis.

Front-wheel drum brakes only — the rear wheels unbraked entirely. To start the engine, the driver exited the vehicle, pulled a starter cord, and ran back before the car moved, which it would do, unprompted, because there was nothing holding it. The carburettor sat in the footwell directly in front of the accelerator pedal. Early models had no guard over the propeller. Later ones got a wire mesh screen. Whether this made pedestrians feel better is not recorded.

The 1921 D.21 production series used the ABC Scorpion, a horizontally opposed flat-twin of approximately 1,100 to 1,200 cubic centimetres, built by A.B.C. Motors Ltd. at their Hersham, Surrey factory. Its French fiscal rating of 8 CV should not be confused with its actual brake output of roughly 30 horsepower — a conflation that has propagated through English-language automotive writing for decades. Normal top speed for a production Hélica was 100 to 110 km/h. Fuel consumption ran to about 8 or 9 litres per 100 kilometres. By 1921 standards, this was quick and economical.

Bodies were built by Paulin Ratier, who also supplied the propellers. Two configurations were offered: the open torpedo style, driver and passenger exposed to everything the world in front of them had to offer, and the enclosed conduite intérieure, a closed cockpit whose claustrophobic dimensions gave passengers the distinct sense of occupying the nose cone of a small torpedo rather than a conventional motorcar. Some examples ran Anzani 3-cylinder radial engines instead of the ABC twin. The Monaco car — held in the collection of the Prince of Monaco — uses a Poinsard flat-twin of 1,250 cc producing 25 horsepower at 2,200 RPM, a configuration not found in any other documented survivor.

The Paris Motor Show and Its Consequences

Leyat exhibited the D.21 at the 1921 Salon de l’Automobile in Paris. Six hundred inquiries followed. Among the stated orders was one attributed to King Alfonso XIII of Spain, documented in the Musée des Arts et Métiers’ records. Leyat filled none of these orders. He could not. The workshop at Quai de Grenelle could not produce cars at that volume, and the financier who might have solved that problem — the propeller manufacturer Levasseur, who had backed the 1919 prototype — had by then walked away. He was not the last investor to look at a spinning propeller two feet from the driver’s face and decide against involvement.

A polytechnicien named Joseph Archer took a manufacturing licence, produced five Hélicas, then designed his own propeller vehicle, the Éolia. Leyat sued him for counterfeiting. The Ratier company filed a propeller-car patent in January 1923 and tested their version on the streets of Montrouge, where their factory stood at 155 route de Châtillon. Both vehicles remained one-offs. Money ran out. Interest subsided. Leyat moved to Meursault, in the Côte-d’Or, in 1922 — the wine country, which is worth noting, though he went there to build gliders, not drink — and serial production of the Hélica was finished.

170 km/h at Montlhéry

On 7 September 1927, at the Autodrome de Linas-Montlhéry south of Paris, a propeller vehicle designed by Marcel Leyat reached 170 kilometres per hour — 106 miles per hour. The Musée des Arts et Métiers records this carefully. The vehicle was an Hélica volante privée de ses ailes: a flying Hélica, an aircraft prototype, tested without its wings. Three wheels. The ABC engine. Not a standard production road car. The production cars topped at 110 km/h; this purpose-built machine, stripped of everything that wasn’t essential to moving fast in a straight line, hit 170 on a banked oval. Whether the run was officially timed and ratified by the Automobile Club de France or the FIA is not confirmed by surviving documentation. It was a private test at a recognised circuit and it stands, cited consistently by French automotive historians for nearly a hundred years, as the number.

Two Stories That Won’t Die

The coat comes up in nearly every English-language account of the Hélica. Somewhere — no source with a date, a specific location, a publication name, or a named victim has yet been produced — a Hélica allegedly shredded a pedestrian’s overcoat with its propeller. The car’s nickname, hachoir sur roulettes — mincer on wheels — was coined by contemporaries who understood perfectly well what an unguarded propeller could do at low speed in a crowded street. The coat story is consistent with that reputation and consistent with basic physics. It is also, as of this writing, unverified. The most likely source is Gustave Courau’s 1979 memoir Mon hélice au pays des merveilles, which has not been digitised. Until it is, or until a dated newspaper account emerges, this is a plausible and circulating anecdote without a paper trail.

The road ban is less forgivable as a myth because it contradicts documented evidence. The story holds that French authorities eventually prohibited the Hélica from public roads. No such prohibition has been found. Courau drove his example commercially for a decade, using it to call on clients, without recorded interference from traffic authorities. Chassis number four — the 1921 conduite intérieure now at the Louwman Museum in The Hague — was described as recently as 2020 as toujours immatriculée, still registered, legally capable of driving on an open road. The Hélica ceased production because Leyat ran out of money and returned to aviation. Not because the government shut him down.

What Survived

The Musée des Arts et Métiers in Paris holds the most extensively documented survivor: the first car of the D.21 series, Inv. 16863. Originally intended for a British buyer who switched his order to an enclosed model at the last moment, it passed to Gustave Courau, who drove it across France for business until 1930, then donated it to the museum in 1935 after its testing laboratory evaluated the motor and declared the design ‘particularly interesting.’ Conservation work from 2015 to 2017 preserved traces of the working life still readable on the body: advertising inscriptions for La Gellicyne soap and for an insurance company called La Participation, painted on by Courau during his decade with the car. It is displayed now in the building’s former church of Saint-Martin-des-Champs. A Romanesque nave. A propeller car. The juxtaposition is not accidental — the museum has a sense of humour.

The Louwman Museum’s car spent most of the twentieth century with the Bouzanquet family, who inherited it from the Peugeot family, who had it from Leyat. During the German occupation, soldiers found it hidden in an outbuilding, attempted to drive it, could not manage the rear-wheel steering, ran it into a tree, and destroyed the propeller. Grandson Jean-François Bouzanquet demonstrated the repaired car under power at Goodwood in July 2003. He drove it again at the Hampton Court Palace Concours of Elegance in September 2020. The Louwman acquired it in 2025.

A fourth example with a closed body has been documented at the National Motor Museum at Beaulieu in Hampshire. Whether this conflicts with the Louwman’s claim to hold the only surviving conduite intérieure, or whether the Beaulieu car has since changed hands or configuration, has not been conclusively resolved.

The Lane Motor Museum in Nashville holds a replica, not an original — built from original Leyat plans discovered in a Meursault attic, fitted with a vintage V-twin engine.

The End of Marcel Leyat

He kept working. Gliders in Meursault through the 1930s. The aile vivante — oscillating-wing aircraft — with the industrialist André-Félix Jacquemin. Ministry of War contracts through 1946. The MALER music education method. Alternative keyboard designs. On 5 and 11 July 1977, aged ninety-two, he gave an extended oral history interview at his home in Thiais, south of Paris — two tapes, four hours, archived at the Service historique de la Défense as AI/8/Z/81. He was precise, detailed, and incorrect about a few things, as a man recounting events from sixty-eight years earlier is entitled to be.

He died in December 1986. Most sources give the 3rd; the SHD’s own archival record shows the 4th. He was 101 years old. He had flown gliders in 1909. He had built propeller cars in 1919. He had watched compact discs go on sale in France in 1982 and outlived the entire vinyl era of the music industry. In December 2021, on Amazon Prime, Richard Hammond drove a Hélica and called it a gigantic death trap. Hammond was not wrong. He was also, by about ninety years, somewhat late to the observation.