Leduc

Leduc

Hydro Leduc

René Leduc built aircraft that were mostly engine: hollow ramjet tubes with a pilot inside, launched from airliners in mid-air, until the money ran out and he switched to hydraulic pumps.

Defunct 1958Status
4Vliegtuigen geregistreerd
LandFrankrijkOprichtersRené LeducHoofdkwartierFrance (Hydro Leduc later at Azerailles)StatusDefunct 1958
Het verhaal

Leduc: the company and the aircraft that made its name

An apprentice with a patent

René Leduc left school at 14 to become an apprentice mechanic, fought in the artillery in the First World War, then studied engineering. Working at Breguet he filed, in 1933, a patent on the thermo-propulsive nozzle, the basis of the ramjet. By 1937 he had started building an aircraft around it, and construction continued semi-secretly at Breguet during the German occupation. The idea caught the attention of Louis Breguet and the Ministry of Aviation, which funded tests of small-scale prototypes.

Launched from a mothership

The result, the Leduc 0.10, was a fuselage that was essentially the engine: the pilot sat in an inner shell while air rushed through the gap around him into the ramjet. Because a ramjet gives no thrust at a standstill, the 0.10 was carried aloft on top of a Languedoc airliner and released. Its first powered flight, over Toulouse on 21 April 1949, was one of the first flights anywhere powered solely by a ramjet. The larger 0.21 made 284 free flights and reached Mach 0.95.

From ramjets to pumps

The final step was the swept-wing 0.22 interceptor, which added a turbojet so it could take off by itself and first flew on 26 December 1956. In 1958 the French Air Force cancelled it for budget reasons. Leduc turned his company to hydraulics as Hydro Leduc, which made pumps for excavators, and ran it until his death in 1968. The 0.22 had been ordered to a 1953 requirement for an interceptor able to take off from a 940-metre grass runway, armed with two air-to-air missiles, in competition with the Nord Gerfaut and Griffon.

René Leduc built aircraft that were mostly engine: hollow ramjet tubes with a pilot inside, launched from airliners in mid-air, until the money ran out and he switched to hydraulic pumps.Leduc · verified 2026-10-03

In één oogopslag

Leduc in numbers

Het bedrijf

Kortom
Ramjet pioneer

  • Founded by engineer René Leduc
  • Ramjet patent filed 1933
  • Aircraft work ended 1958

Productie

Het meest bekend om
Leduc 0.10

  • 0.10: among the first ramjet-only aircraft
  • 0.21: 284 free flights
  • 0.22 supersonic interceptor prototype

Vandaag

Nu
Hydro Leduc

  • Company converted to hydraulic pumps in 1958

De cijfers

Leduc 0.21 free flights
284
Leduc 0.10 top speed
Mach 0.85
Hydro Leduc workforce
over 200

Het vliegtuig

Every notable Leduc aircraft

Vliegtuig Rol Eerste vlucht Gebouwd Status Opmerking
Leduc 0.10 Ramjet research aircraft 1947 3 Gepensioneerd Glide tests from October 1947, first powered flight 21 April 1949; built at Breguet
Leduc 0.16 Ramjet research aircraft 1951 Gepensioneerd Third 0.10 airframe with wingtip turbojets, later converted back
Leduc 0.21 Ramjet research aircraft 1953 2 Gepensioneerd About 30 per cent larger than the 0.10; reached Mach 0.95
Leduc 0.22 Mixed-power interceptor prototype 1956 one flown Gepensioneerd Ramjet plus turbojet; cancelled 1958 before the second was finished

Plaatsen, mensen, archieven

Where Leduc built, who led it, what it achieved

Mensen

  • René Leduc · founder, engineer — Born 1898 at Saint-Germain-lès-Corbeil, died 1968 at Istres; ramjet pioneer

Records en primeurs

  • Leduc 0.10 made one of the first flights powered solely by a ramjet, 21 April 1949
  • Leduc 0.10 climbed at 40 m/s, better than the best jet fighters of the time

Tijdlijn

Leduc, year by year

1898

René Leduc born

1933

Patent on the thermo-propulsive nozzle, the basis of the ramjet

1937

Construction of the Leduc 0.10 begins

1947

Unpowered glide tests of the 0.10 begin

1949

First powered flight of the 0.10 over Toulouse

1953

Leduc 0.21 flies

1955

Leduc 0.21 shown at the Paris Air Show

1956

Leduc 0.22 interceptor first flies

1958

Programme cancelled; company converts to hydraulics as Hydro Leduc

1968

René Leduc dies at Istres


Vragen en antwoorden

Everything people ask about Leduc

What was special about Leduc aircraft?
They were powered by ramjets, with the fuselage itself forming the engine duct around the cockpit.
How did the Leduc 0.10 take off?
It could not. It was carried on top of a mother aircraft such as a Languedoc airliner and released in flight.
Why was the Leduc 0.22 cancelled?
The French Air Force ended the programme in 1958 for budgetary reasons.
Does Leduc still exist?
The aircraft work ended in 1958; the company continued in hydraulics as Hydro Leduc.



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Geverifieerd op 3 oktober 2026.