A French revolution

by Dr. Marshall Michel
86th Airlift Wing historian

Much of the rapid fall of France in World War II can be blamed on the low technology of its combat aircraft, but the post-World War II French aviation industry came back with a vengeance.

Through the late 1960s, France produced a series of combat aircraft that were equal to or superior to any produced in the U.S., Soviet Union or U.K. Not only did the industry produce these aircraft, but they also showed remarkable creativity and flew some of the most interesting jet prototypes in the world during the late 1940s and 1950s.

One of the most unique of these was the Landuc series of ramjet aircraft – the brain child of French designer René Leduc in 1938, before World War II.

A ramjet is a continuous combustion jet engine with no rotary compressor at the inlet; in fact, a ramjet contains no major moving parts. This simplicity is an obvious advantage, but without a way to pull in air, ramjets have to have considerable forward motion to ‘ram’ the air through the engine and produce thrust.

Leduc was able to keep his ramjet project secret from German occupation authorities and, once the war was over, his company produced his first ramjet aircraft – the Leduc 010. It was very large and carried its pilot in a center cone surrounded by the engine intake. And to obtain an initial speed necessary, the 010 was dropped at altitude from a carrier aircraft, a specially-modified, four-engine French transport – the  SE-161 “Languedoc.”

The Leduc 010’s first flight – the first flight of an aircraft solely propelled by a ramjet engine – took place April 21, 1949, and in just a few flights, the Leduc 010 demonstrated the viability of the ramjet and showcased the ramjet’s best characteristic – an incredible rate of climb that far exceeded the best jet fighters of the time.

Unfortunately, the two Leduc 010s were destroyed in accidents, but Leduc persisted with the Model 016, similar but with wingtip-mounted turbojets to enable unassisted

This configuration had problems, however, and Leduc returned to the carrier aircraft for his next version, the Model 021. Two 021s were built and, from 1953 to 1956, they completed a flight test program to develop viable throttle controls for the ramjet.

The Model 021 was followed by the Model 022, the prototype of a Mach 2 fighter, which featured slightly swept wings and a coaxial turbojet-ramjet power plant that allowed it to take off and fly on its own power without the assistance of a carrier aircraft. The 022 first flew in December 1956 and flew 141 flights during the following year, but could not exceed the speed of sound because of the drag of its non-area ruled fuselage. Additionally, the 022 was competing with what was to become one of the world’s great fighters, the Dassault Mirage, and the Leduc ramjet program was canceled in 1958.