Since 1929 aeronautical engineer René Leduc concentrated on development of
ramjet power for aircraft. He patented his idea in 1933 and produced a small
unit of 1.18 inch (30 mm) in diameter, which developed 8.8 lb (4 kg) thrust in
1935. Leduc demonstrated the practical application of the ramjet engine in June
1936, and the next year the French government contract number 407/7 ordered the
construction of the Leduc 0.10 ramjet-powered aircraft. Design and construction
began immediately at the Breguet workshops at Villacoublay (near Paris) and the
aircraft was nearly finished early 1940.
Due to the German invasion, Breguet evacuated the Paris area, the aircraft
being transferred to Montaudran in Toulouse, later being destroyed in a
bombardment of the factory. In 1945 work began again and by November 1946 the
aircraft was ready. As the ramjet has no static thrust (the combustible mixture
being compressed by forward speed only) the 0.10 was fitted on top of a
modified Sud-Est SE-161 Languedoc four-engined transport. At least four
Languedoc's were used in the program, including F-BATF (c/n 6) and F-BCUT (c/n
31).
The first composite flight was from Blagnac on November 19, 1946, but it was
not until October 21, 1947 before the 0.10 was released and made its first
unpowered flight. Only two more unpowered flights were made before the first
powered flight. On April 21, 1949, with test pilot Jean Gonord in the Leduc
0.10-01 and Colonel Jean Perrin piloting the Languedoc, the 0.10-01 was
released over Blagnac, the burners were lit and thus became the first aircraft
solely propelled by ramjet power. The aircraft was released in a shallow dive
flying at 13,123 ft (4,000 m) at 267 mph (430 kmh) and in the following 9
minutes the 0.10-01 reached 423 mph (680 kmh).
The 0.10 proved the extraordinary capabilities of the athodyd engine (a simple, essentially tubular jet engine), in
particular its incredible rate of climb. During the test flights, producing
4,409 lb (2,000 kg) thrust, the aircraft was able to climb 7,792 ft (2,375
m)/min, and reached 500 mph (805 kmh) at 36,089 ft (11,000 m). A second
aircraft (0.10-02) was built and flown in the Paris area, but from 1951 testing
continued at Istres, near Marseille. On February 8, 1951 a third and similar
aircraft was flown, the Leduc 0.16. Initially fitted with a 661 lb (300 kg)
thrust Turboméca Marboré I turbojet at each wing tip for standby power during
landings, these soon were replaced by mass balances.
The CEV (Centre d'Essais en Vol = Flight Test Center, part of the French
ministry of defense) at Istres also conducted test flying. In 1951, a technical
failure caused the destruction of one of the 0.10s seriously injuring the CEV
test pilot, Jean Sarrail. The following year the second 0.10 was written off
following another accident in which Leduc test pilot Yvan Littolff was
seriously injured.
Next type to join the test program was the Leduc 0.21. Of new design, it was
30% larger than the 0.16, and two of these were built. Like the Leduc 0.10 and
0.16 it was a subsonic test vehicle for ramjet power, but also provided data
for a proposed Mach 2 interceptor. The Leduc 0.21-01 commenced air tests on top
of the Languedoc transport in May 1953, making its first powered flight on
August 7, 1953, followed by the 0.21-02 on March 1, 1954.
The proposed Mach 2 interceptor prototype, the Leduc 0.22-01 was fitted with a
Turboméca Atar D.3 turbojet. This made it possible to take off on its own
power, and it did so for the first time in the hands of Jean Sarrail on
December 26, 1956. Not before the 34th flight the ramjet was fired on May 18,
1957, a further 80 flights were conducted till December 21, 1957 when the
program came to a halt due to cutbacks in military contracts.
René Leduc left the aircraft manufacturing scene; the surviving 0.10 and sole
0.22-01 were stored and are now on display in the Musée de l'Air at Le Bourget.
0.10
Alfred Damen collection 0.22
Walter van Tilborg collection
Specifications (0.21)
Type:
Experimental ramjet monoplane
Engine:
14,330 lb (6,500 kg) static thrust at 556 mph (1,029 kmh) Leduc fuselage
duct ramjet
Span:
38 ft 0.71 in (11.60 m)
Length:
41 ft 0.11 in (12.50 m)
Height:
9 ft 0.28 in (2.75 m)
Empty Wt:
8,345 lb (3,785 kg)
Max T/O Wt:
13,228 lb (6,000 kg)
Max speed:
576 mph (1,066 kmh)
Ceiling:
65,617 ft (20,000 m)
Climb:
initial 39,370 ft (12,000 m)/min, falling to 2,887 ft (880 m)/min at 49,213
ft (15,000 m)