Bréguet-Dorand Gyroplane Laboratoire

https://en.wikipedia.org/wiki/Br%C3%...ne_Laboratoire

The Gyroplane Laboratoire was an early helicopter. Its designer, Frenchman Louis
Bréguet, had already experimented with rotorcraft in 1909; however, he chose to
concentrate on airplanes until the end of the 1920s. In 1929 he announced a set
of patents which addressed the flight stabilization of rotorcraft, and, in 1931,
Bréguet created the Syndicat d'Etudes de Gyroplane (French for "Syndicate for
Gyroplane Studies"), together with Rene Dorand as technical director. Their goal
was the development of an experimental helicopter, the Gyroplane Laboratoire.

The aircraft consisted of an open steel tube framework, within which the engine,
fuel tank, controls and pilot were situated, together with a tail assembly with
plywood tail surfaces. The tailwheel landing gear was installed with the
mainwheels on outriggers and with an additional small wheel at the front to
avoid nosing-over during landing. Power was provided by a 240 HP Hispano radial
engine which propelled the two contra-rotating, coaxial rotors. The coaxial
rotor design was chosen because with the rotors turning in opposite directions
the torque from one rotor was canceled out by the torque produced by the other
rotor.

The two twin-bladed rotors made of metal were shaped like arrows and
incorporated both cyclic and collective pitch blade control, with which movement
around the pitch and roll axis was controlled, as well as climb and descent.

Role
Prototype helicopter

Manufacturer
Bréguet/Dorand

Designer
Louis Bréguet

First flight
26 June 1935

Status
Destroyed

Number built
1

The Bréguet Dorand aircraft was finished in 1933. After ground tests and an
accident, the first flight took place on 26 June 1935. Within a short time the
pilot, Maurice Claisse, was setting records with the aircraft :

*14 December 1935: Closed-circuit flight with 500 m diameters

*26 September 1936: Height of 158 m

*24 November 1936: Flight duration of 1:02:50 hours over a 44 km closed circuit
at 44.7 km/h

*Maximum speed 120 km/h

The Gyroplane Laboratoire and its accomplishments were soon overshadowed by the
German Fw 61. Bréguet and Dorand continued to conduct further experiments to
improve the design until the aircraft experienced a hard landing in June 1939.
Development was abandoned with the outbreak of World War II. The only prototype
was destroyed in 1943 during an Allied air attack on the airfield at
Villacoublay.

Specifications (Gyroplane Laboratoire)

General characteristics
Crew: 1
Length: 8.92 m (29 ft 3 in)
Height: 2.79 m (9 ft 2 in)
Empty weight: 1,430 kg (3,153 lb)
Max takeoff weight: 1,950 kg (4,299 lb)
Powerplant: 1 × Hispano-Suiza 8F V-8 water-cooled piston erngine, 225 kW (302
hp)
Main rotor diameter: 15.89 m (52 ft 2 in)
Main rotor area: 198.33 m2 (2,134.8 sq ft)

Performance
Maximum speed: 120 km/h (75 mph, 65 kn)
Range: 44 km (27 mi, 24 nmi)
Service ceiling: 158 m (518 ft) achieved



*