Breguet-Richet Gyroplane No.1 (France)

When it rose vertically from the ground with its pilot in the late summer of 1907, the Gyroplane No.1 built by Louis and Jacques Breguet in association with Professor Charles Richet had to be steadied by a man stationed at the extremity of each of the four arms supporting the rotors. It cannot, therefore, take the credit for being the first helicopter to make a free flight, even though the ground helpers contributed nothing towards the lifting power of the rotors; but it was the first machine to raise itself, with a pilot, vertically off the ground by means of a rotating-wing system of lift. Basically, the Breguet machine consisted of a rectangular central chassis of steel tubing supporting the powerplant and the pilot; from each corner of this chassis there radiated an arm, also of steel tube construction, at the extremity of which was mounted a fabric-covered 4-blade biplane rotor, making a total of 32 small lifting surfaces. One pair of diagonally opposed rotors rotated in a clockwise direction, the other pair moving anti-clockwise. The pilot, M.Volumard, was reputedly chosen at least partly because of his small stature – he weighed only 68kg. Authorities differ over the date of the Breguet machine’s first flight at Douai, 24 August and 19 September 1907 being quoted with equal assurance; on this occasion the aircraft rose to about 0.60m. Take-off to some 1.50m was achieved during a test on 29 September, and similar heights were reached in several subsequent tests, but the Breguet-Richet aircraft was neither controllable nor steerable in a horizontal plane.

In 1908 the Breguet-Richet collaboration produced a No.2 Gyroplane, powered by a 55hp Renault engine and having two forward-tilting 2-blade rotors with a diameter of 7.85m and, in addition, fixed wings giving an extra 50m2 of lifting surface. This machine made a number of successful flights in the summer of 1908, but was severely damaged in a ‘heavy’ landing on 19 September. In rebuilt form as the No.2bis it was displayed statically at Paris in December 1908 and made one test flight in the following April, but a month later the Breguet premises were wrecked by a hurricane. This, and the shortage of contemporary engines with an adequate power/weight ratio, caused Breguet to abandon rotary-winged development until the appearance of the Breguet-Dorand design in the 1930s.

At last, after the turn of the century, a new lightweight power plant became available. Fitted to the early automobiles and box-kite airplanes, the gasoline engine began to prove itself. In 1907, four years after the Wright brothers had flown the first controllable airplane, French designer Louis Breguet built a primitive helicopter that could lift a man into the air.

It was a time of the flowering of arts and sciences in France. Although the first airplane had been flown in the United States, for the first decade the French, with Gallic passion and enthusiasm, led the world in aviation research and progress. The helicopter was a case in point, for the first machines to fly were French. The inspiration stemmed, perhaps, from the “Trium-virat Helicoidal” of fifty years before.

A purist might scorn the first hops in the year 1907 as not actually being flights, since the machine was held steady by four assistants to prevent any erratic movement. But the Breguet-Richet Gyroplane No.1 did take a Monsieur Volumard — chosen for his light weight — into the air for the first time on August 24, 1907. The machine rose only to a height of about two feet, remaining in the air for one minute. Unhappily, it was not sufficiently steady or controllable for free flight, and eventually testing was discontinued in favor of building a completely new machine.

The following year Breguet produced his second helicopter. It was furnished with twin 25-foot rotors, powered by a 55-horsepower Renault engine, with a set of biplane wings for good measure. On July 22, 1908, it rose vertically to the respectable height of 4.5m and flew for a short period of time, apparently under control, but the machine was completely wrecked upon landing.

It appeared more-or-less contemporarily with the airplane, when Volumand — chosen as pilot largely on account of his modest weight of 64kg — was lifted clear of the ground at Douai in France on 29 September 1907, in the elaborate Gyroplane built by Louis and Jacques Breguet under the guidance of Professor Charles Richet. The aircraft achieved a height of only 60 cm (2 ft) and was totally uncontrollable, to the extent that it had to be steadied by four assistants. But it was the first time a mechanical device had raised itself vertically from the ground with a man on board, using a rotary wing system, even if it could not be described as a free flight.

The Breguet-Richet craft had a 45hp Antoinette engine and the rotors, only the rotation speed of which could be controlled, were 8m in diameter. A year later, Gyroplane No.2 appeared, with a more powerful 55hp Renault engine and two forward-tilting two-blade rotors, of slightly smaller diameter than the main lifting surfaces, which provided the thrust for forward movement. In the late summer of 1908, this aircraft was badly damaged by a heavy landing, but was rebuilt and flew again next spring.

Paul Cornu Helicopter (France)

The first true flight, free of any tie-down ropes, apparently was made by Paul Cornu, in another French machine later the same year, on November 13. His helicopter had two rotors mounted in tandem, one behind the other. The pilot sat between them, in intimate proximity to the little 24-horsepower Antoinette engine. The helicopter rose no more than 2m, and the longest flight lasted only a third of a minute. Nevertheless, it flew, completely free of any attachment to the ground. Today it would be said that the pilot “had not gotten out of ground effect”. To steer, to rock the ship from side to side, or to nose up and down, there were movable flat surfaces—control vanes—mounted under the rotors so the airflow would push against them. The system on the Cornu machine was ineffectual, though control vanes were used with better effect on later aircraft.

The Breguets were not alone, however, in that their record was challenged by Paul Cornu, a bicycle maker from Lisieux, whose machine, powered by a small 24 hp engine, could only have been called the “flying bicycle,” consisting as it did of two large, spoked wheels on to which short, paddle-shaped wings were splined to form twin two-blade rotors about 6m in diameter. The rotors were belt-driven and contra-rotating. The central frame supported the engine, pilot seat and fuel tank, and the whole contraption weighed just over 250kg. Various flights were made, including the notable occasion when Cornu succeeded in remaining airborne for about 20 seconds at a height of 30cm on 13 November 1907. Thus it was he who was officially recognised as having made the first free flight.

The first aeroplane to take off vertically with its pilot and make a free flight entirely without assistance from or connection with the ground was the ‘flying bicycle’ designed and built by Paul Cornu in 1907. It achieved this feat at Coquain-villiers, near Lisieux, on 13 November 1907, though the distinction is a slightly academic one since the aircraft remained in the air for only some 20 sec. at an ‘altitude’ of about 0.30m. The chassis was in the form of an open ‘Vee’ supporting the engine, fuel tanks and pilot’s seat in the centre and resting on a four-wheeled landing gear. The rotors were paddle-shaped and fabric-covered, mounted on large horizontal, bicycle-type wheels situated one at each end of the machine and turned by a belt drive from the engine. The design followed that of a small scale model made by Cornu a year or so previously with 2.25m rotors, a 2hp Buchet engine and a weight of 13kg. The full-scale machine made its second flight with Cornu’s brother hanging on to the framework, increasing the total weight to 328kg, and take-offs to about 2m were made later carrying the pilot only. However, the helicopter’s transmission system was suspect, its framework too flimsy, and – despite the movable fore and aft vanes – its controllability was largely ineffectual; and these factors, combined with a lack of funds, caused Cornu to forsake the further development of his historic but impractical design.

Ellehammer (Danmark)

Jacob Christian Ellehammer must surely rank among the most versatile of aviation’s early pioneers. First apprenticed as a watchmaker, he then qualified as an electrical engineer; he made one of the earliest motor-cycles built in Denmark, and also designed his own internal combustion engines. His 3-cylinder piston engine of 1903 was perhaps the world’s first radial engine, and his experiments in aviation, started two years later, embraced monoplanes, biplanes, triplanes, flying boats and helicopters.

Ellehammer’s first studies of rotary-winged flight began in 1910, and various experiments were carried out in 1911 with a scale model helicopter. The full-sized machine that he built in the following year would today be defined as a compound helicopter, for its 6hp engine (also designed by Ellehammer) drove both the rotor system and a conventional propeller. The lifting rotors were of an ingenious pattern, consisting of two contra-rotating rings, each of 5.97m diameter, the lower one being covered with fabric to increase the lift. At regular intervals round the perimeter of the wings were six vanes, each about 1.50m long and 0.66m wide and pivoting about its horizontal axis. The rotor system was driven via a hydraulic clutch and gearbox, all designed by Elle-hammer, and the rotor vanes’ angle could be altered in flight by the pilot — an early example of cyclic pitch control. After several successful indoor take-off tests, during which the machine was probably tethered, Ellehammer’s machine made a free vertical take-off later in 1912, in front of witnesses who included H.R.H. Prince Axel. Tests with the 1912 helicopter continued until late in September 1916, when it overturned after a take-off and the machine was wrecked when the rotors spun into the ground.

Ellehammer then put aside his helicopter experiments until about 1930, when he began to evolve some new projects. One of these was, in effect, a parasol monoplane in whose wings was a huge circular cut-out with two contra-rotating rotors turning inside it. Even more novel was a proposal in the mid-1930s for a helicopter driven by compressed air. As with the previous project, only a working model was built, powered by a vacuum cleaner motor. In the full-sized aircraft Ellehammer proposed to have a radial engine driving a powerful air compressor. A substantial pylon over the fuselage was topped by a metal disc, made to rotate by the reaction from expelling compressed air through slots in its underside. The centrifugal force of the rotating disc was sufficient to unsheath four spring-loaded rotor blades; when take-off had been accomplished, these were retracted back into the disc and the compressed air stream diverted to an efflux at the rear of the aircraft to give it forward movement.

Oehmichen (France)

Etienne Oemichen, a young engineer with the Peugeot motor car company, began to experiment with rotating-wing designs in 1920, and in all designed and built six different vertical take-off machines. When the first of these failed to develop enough lift from its twin rotors and 25hp engine to rise off the ground, he added a hydrogen-filled balloon on top of it to give it added stability and lift. The most noteworthy – and most striking – of his aircraft was the helicopter No.2, which had no less than 4 rotors and 8 propellers, all driven by a single 120hp Le Rhone rotary engine when it flew for the first time on 11 November 1922. A 180hp Gnome engine was substituted later. The Oemichen No.2 was basically a steel-tube framework of cruciform layout, with 2-blade paddle-shaped rotors at the extremities of the four arms. The angle of these blades could be varied by warping. Five of the propellers, turning in a horizontal plane, served to stabilise the machine laterally; another propeller mounted at the nose was for steering the helicopter; and the remaining pair acted as pusher propellers for forward propulsion. The opposing pairs of rotors were of slightly different diameters. The Oemichen No.2 exhibited, for its time, a considerable degree of stability and controllability, and in all made more than a thousand test flights during the middle 1920s. By 1923 it was able to remain airborne for several minutes at a time, and on 14 April 1924 it established the first-ever FAI distance record for helicopters of 360m. Three days later it increased this to 525m and on 4 May was airborne for 14 min, flying more than a mile and completing in the process the first 1km closed-circuit flight by a helicopter in 7 min. 40 sec. Oemichen was, however, dissatisfied with the modest heights to which No.2 was able to fly, and from the third machine onward he adopted a single main rotor layout, accompanied by two smaller anti-torque rotors. His last design, in 1938, reverted to the balloon-assisted principle of his first aircraft.

In France, Etienne Oemichen, a young engineer at Peugeot, began rotary wing experiments in 1920, building a total of six different machines. His second machine flew unassisted on 11 November 1922. The Oemichen No. 2 had an “X”- shaped, tubular frame with a wide two-bladed rotor at the end of each arm. For control and lateral movement, eight small propellers were used: five horizontal propellers with variable and reversible pitch for lateral stability, another propeller at the nose for steering, and another pair of pushers for forward motion. By 1923, the Oemichen No. 2 was able to remain airborne for several minutes and on 14 April 1924, it established the first rotary wing distance record: 360m. On 4 May, it completed the first 1km closed circuit flight by a rotary wing vehicle in 7 minutes 40 seconds to win a 90,000 franc prize. Maximum endurance was 14 minutes. Despite the fact that it was able to demonstrate sufficient controllability and power in ground effect for this historic flight, it was not a practical flying machine. In recognition of the impracticality of the machine, Oemichen began pursuing a series of aircraft with a single-main rotor and two anti-torque rotors, but had little success.

Pescara No.3 (Spain)

It is unfortunate that more complete records have evidently not survived of the later Pescara helicopters, for despite their apparent clumsiness they represented for their time an important step forward in helicopter design technology that deserves recognition. The Spanish Marquis Raul Pateras Pescara built his first helicopter in Barcelona in 1919-20. It was a clumsy machine, weighing some 600kg without fuel or pilot and powered by a 45hp Hispano engine. Each of the 2 co-axial rotors had a diameter of 6.40m and was made up of 6 biplane pairs of blades giving a total of 24 lifting surfaces, but the little Hispano was not powerful enough to raise the machine off the ground. A modified form of this aircraft, with a 170hp Le Rhone rotary engine, did just get off the ground in May 1921, but it was far from being a stable or satisfactory design. In 1922 Pescara moved to France, where the No.2 did succeed in rising some 1.5m during tests carried out for the Service Technique de I’Aeronautique.

Pescara’s most successful helicopter was the No.3, which was built in 1923 and by January 1924 was capable of making flights of some 10 minutes’ duration. The same co-axial rotor system was employed, larger twin rotors each with 4 pairs of blades turning around a ‘totem pole’ rotor mast. A 180hp Hispano-Suiza engine, for which the Lamblin radiator was situated at the rear of the craft, provided the power. Although a heavy and cumbersome machine the Pescara No.3 was a simple design when compared with its closest contemporary, the Oemichen No.2, and makes an interesting comparison with the Breguet-Dorand of some ten years later. On 18 April 1924 Pescara flew the No.3 at Issy-les-Moulineaux for a distance of 736m, handsomely beating the record set up by the Oemichen only the day before.

The significance of this achievement lay in the fact that Pescara’s machine, unlike the Oemichen or any other rotorcraft up to that time, did not rely on conventional propellers rotating in the vertical plane to give the aircraft forward motion. Instead, the pitch of the 16 lifting surfaces could be altered in flight by warping them, and the rotor head could be tilted to give the blades a degree of forward thrust. The speeds thus achieved were extremely modest, but the Pescara No.3 exhibited the first convincing demonstration of the principles of cyclic and collective pitch control. Autorotation of the rotors was also provided for in the event of engine failure.

Reference is made in some quarters to the Pescara No.3F, which was possibly a modification of the No.3 and not a new machine. This appeared in the early part of 1925 and had a 250hp engine, with a cut-down propeller fulfilling a cooling function only. It offered no great improvement over the No.3, and later that year Pescara returned to Spain and entered the motor car industry. He seems to have been discouraged from further serious helicopter development by the emergent success of Cierva with the autogiro, though he was associated with the little French-designed Pouit S-4 later in the 1920s.

Pescara’s No. 3 machine, completed in 1923, used four 7.2m diameter 4-blade biplane rotors and no other propulsion mechanisms: the pitch of the 16 lifting surfaces could be altered in flight by wing warping. This was the first credible use of cyclic and collective pitch control, the essential ingredients of a helicopter. The rotor hub could be tilted for some measure of forward motion, but speed was only about 13km/h. This slow speed was one of the main reasons that the early “helicopters” used auxiliary propellers for forward propulsion. In September 1923, Pescara almost became the first person to complete a 1km circuit, but the machine crashed and was severely damaged. The next spring, four days after Oemichen’s first FAI distance record, Pescara doubled it to 736m.