the ramjet's main problems is its absence of thrust when it is
motionless. To obtain an initial speed necessary for the startup
of the engine, Rene Leduc thought of releasing his apparatus at
altitude from a transporter aircraft. The selected aircraft was
a four-engine transport SE-161 "Languedoc" especially
Thus on November 19th 1946, with test pilot Jean Gonord
at the controls of the Leduc 010 mounted atop Languedoc number
6, the first flight was accomplished in composite from the small
airfield of Blagnac. The transporter pilot was Colonel Jean Perrin,
who became the principal specialist for this type of missions.
It would be several months before the 010 would be released in
free gliding flight for the first time, which occurred on October
21st, 1947. At the end of this first free gliding flight,
the plane overshot the short runway and the tires blew out. The
enthusiasm of Gonord for the aircraft however, overcame the reservations
of the official specialists presents at the demonstration and
the flights would continue.
Thus, after some flights in composite, two free gliding flights,
followed by a long period of inactivities while waiting for the
arrival of the essential equipment, the historical flight would
finally take place. On April 21st, 1949, after being
released overhead Blagnac, test pilot Jean Gonord lit up the engine
and established a climb using only the ramjet engine.
During the war, various tests had been conducted (particularly
in the USSR and in Germany, but also in the United States) on
ramjet engines installed experimentally on transporter airplanes.
This type of propulsion was even used on some gun shells to increase
their range, and many other projects were born as well. However,
the flight of the Leduc 010 on April 21st 1949 with
its ramjet operating represents the first flight of an aircraft
solely propelled by a ramjet engine.
After this success, the tests were conducted with full force,
and in just a few flights, the Leduc 010 proved the extraordinary
capabilities of the "athodyd" engine, in particular
its incredible rate of climb.
Even before the cabin was pressurized, Gonord found itself propelled
to 11, 000 meters in just a few minutes. During another
flight, it was the high-attained airspeed, which took him by surprise:
upon reaching Mach 0.85, he encountered the violent effects of
compressibility, which resulted in bounces of more than 600 meters
of altitude. It was undoubtedly the first French airplane to experience
Rene Leduc was unable to go further as a private engineer, while
he was still working part-time for the Breguet Company. Therefore,
he created a company and returned to the Paris area, settling
down in Argenteuil. Obtaining several state contracts for the
construction and the testing of other prototypes, a second 010
was built. The flight testing performed in the Paris area being
strongly handicapped by the unfavorable meteorological conditions,
Rene Leduc in 1951 continued the testing in the South of France,
at Istres in the Provence region.
Two 010 were tested there by Jean Gonord, helped by a second pilot:
Yvan Littolff, under the direction of engineer Jean Corriol. A
third prototype was built, equipped with two additional engines
mounted on the wingtips. It was designated Leduc 016. Unfortunately,
the development of the 016 model proved very delicate, and after
various attempts, the wingtip engines were removed.
A trial run was carried out by the CEV (French flight test center),
with Jean Sarrail as the principal pilot, and under the direction
of Jean Sarrail the test engineer. Unfortunately, following a
technical failure, this trial run was ended with the destruction
of the one of the 010, and with its pilot seriously wounded. The
following year, it was Yvan Littolff who was also seriously wounded,
in an other accident, which resulted in the destruction of the
second 010. Jean Gonord having ended his test pilot career, it
was Jean Sarrail who continued the tests.
The flights continued on the 016, which was then joined by two
new much larger planes: the Leduc 021s. Sarrail and Littolff shared
the test flights on these two airplanes, which relegated the 016
to the Museum in 1953. The two Leduc 021s totaled 385 flights,
including 248 releases in free flights. Once again, other test
flights took place at the CEV in 1955, shortly before the presentation
at Le Bourget airshow. The CEV test pilot was Bernard Witt, with
test engineers André Bourra for the airframe, and especially Charles
Bourgarel for the propulsion portion of this "flying engine".
It is interesting to note that, in addition to the originality
of their propulsion system, the Leduc airplanes were the basis
of numerous innovations. Among them, the use of one of the first
turbines produced in France, used to drive the instruments, the
supply of energy, the jettisoning of the cabin, the hydraulic
servos, and the wings milled in the mass acting as integral structural
The two 021s completed their career when the Leduc 022 accomplished
its first flights, in December of 1956. It was equipped with a
centrally mounted turbojet, which enabled it to take off and fly
on its own power, without the assistance of a transporter airplane.
It totaled 141 flights during the following year, until a taxiing
incident caused damages to the fuselage.
Meanwhile, the progress made by the turbojet engines equipped
with afterburners, and France budgetary difficulties during the
period of crisis in the Algerian war, it signaled the end for
the prototypes in process of development during this period (Trident,
Gerfaut, Durandal, Baroudeur, Griffon, Leduc...).
The tests were definitively cancelled in 1958, and Rene Leduc
was constrained to give up his work as an aircraft manufacturer.
Despite a massive personnel layoff, and very reduced activities,
René Leduc's company still exists, and it is now located in Azerailles,
in the Meurthe-et-Moselle region (east of France), where it manufactures