1936: Focke 61
In 1934, H. Focke decided to branch into rotary wings and acquired a licence for La Cierva's autogyros. From this experience, he began developing the Focke 61. This aircraft's engine had 160 horsepower and a total weight of approximately 1,000 kilograms in flight conditions with a pilot.
In 1936, French industry created the Société Nationale de Constructions Aéronautiques du Sud-Ouest by merging six aviation companies, including Blériot (established in 1905) and Bloch (Marcel Dassault). The company built transport aircraft (i.e. the Bretagne), bombers (the Vautour), a fighter (the Trident) and helicopters.
On May 10, 1936, Rohlfs accomplished the first autorotation landing in the history of the helicopter.
On June 26, 1936, test pilot Ewald Rohlfs performed the first flight lasting 26 seconds. Three flights later, the flight duration increased to16 minutes.
In 1937, Heinrich Focke and Gerd Achgelis founded an aircraft company specialised in helicopters called Focke-Achgelis GmbH. The company is known for developing the FA330, a rotor kite that could be towed by a submarine to search for targets. After World War II, the company discontinued production until 1951, when they began producing gliders. In 1963, the company merged with Vereinigte Flugtechnische Werke (VFW).
In 1937, Pr. Focke, who had been dismissed from Focke-Wulf, teamed up with the pilot Gert Achgelis to create the firm Focke-Achgelis. Carl Bode became the new test pilot of this company.
In the meantime, the famous aviator Hanna Reitsch took over flight demonstrations involving the Focke 61. In February 1938, a series of sensational flights took place in the Deutschlandhalle in Berlin.
On January 29, 1939, C. Bode climbed to an altitude of 3,4207 metres, beating Rohlfs' former record. The Focke 61 then retired with its last flight performed in December 1941.
June 1940: FA223
Following the success of the F61, Pr Focke designed a larger aircraft, the FA223. In the fall of 1939, the first experimental aircraft was completed. The first flight took place on 12 June 1940, but the machine was considered as complete only at the beginning of 1942.
The main characteristics were: speed of 182 km/h, ceiling of 7,100 metres, maximum weight lifted vertically of 4,414 kg, and longest flying time of 3 hours and 42 minutes.
Many flights were conducted in the mountains on unprepared landing grounds, often located as high as 2,300 metres in the Alps.
In 1944, 30 FA223s were ordered, but in the spring 1945 only nine had been built. After the war, one was ferried to England, becoming the first Channel crossing by helicopter 30 years after Blériot did the same with an airplane. In mid-1947, Pr Focke joined the French company SNCASE.
By the end of World War II, a helicopter Department had been created within Société Nationale de Constructions Aéronautiques du Sud-Ouest under the direction of Paul Morain.
Using some mechanical parts and engineers from the German firm Focke, the department developed a vertical-takeoff autogyro powered by a 9.75 metre diameter jet rotor with three blades. It was presented at the first post-war air show in Paris in November 1946.
The SO1100 used a Mathis G7 engine with a maximum power of 175 horsepower. After numerous tie-down tests, the first "free flight" occurred on 7 March 1949, piloted by Claude Dellys. However, the yaw control was insufficient and the carburetion system difficult to adjust.
However, several important modifications from this cancelled program led to the development of the Ariel II version.
June 1948: SE3101
The SE3101 was a small single-seat aircraft, with two small tail rotors in the shape of an inverted V. With a weight of 535 kg, it was powered by a 90 horsepower Mathis engine. In June 1948, Jean Boulet, performed a takeoff at 30 centimetres above the ground. (Boulet obtained his pilot's license six months before; it was the beginning of his long career as a test pilot.
In September, Boulet made the first public display over Villacoublay airfield near Paris. During the months that followed, the tests progressed very slowly, with only 20 flight hours between June 1948 and January 1950. That same year, the tests came to an end.