Development
Professor Henrich Focke had – through his development of the Fw 186, and through his work on the C.19 and license-built C.30 autogyros – come to the conclusion that the limitations of autogyros could only be eliminated by an aircraft capable of vertical flight, the helicopter. He and engineer Gerd Achgelis started the design for this helicopter in 1932. A free-flying model, built in 1934 and propelled by a small two-stroke engine, brought the promise of success. Today, the model can be seen in the Deutsches Museum in Munich.
On 9 February 1935, Focke received an order for the building of a prototype, which was designated the Fw 61, however Focke referred to it as the F 61. Roluf Lucht of the technical office of the RLM extended the order for a second aircraft on 19 December 1935. The airframe was based on that of a well-tried training aircraft, the Focke-Wulf Fw 44 Stieglitz.
Using rotor technology licenced from the Cierva Autogiro Company, a single, radial engine drove twin rotors, set on outriggers to the left and right of the fuselage - the counter-rotation of the two rotors solved the problem of torque-reaction as also shown by Louis Bréguet. The small horizontal-axis propeller directly driven by the engine was purely to provide the necessary airflow to cool the engine during low speed or hovering flight- it provided negligible forward thrust.
Only two aircraft were produced. The first prototype, the V 1 D-EBVU, had its first free flight on 26 June 1936 with Ewald Rohlfs at the controls. By spring 1937, the second prototype, V 2 D-EKRA, was completed and flown for its first flight. On 10 May 1937, it accomplished its first autorotation landing with the engine turned off.
Read more about this topic: Focke-Wulf Fw 61
Famous quotes containing the word development:
“Good schools are schools for the development of the whole child. They seek to help children develop to their maximum their social powers and their intellectual powers, their emotional capacities, their physical powers.”
—James L. Hymes, Jr. (20th century)
“A defective voice will always preclude an artist from achieving the complete development of his art, however intelligent he may be.... The voice is an instrument which the artist must learn to use with suppleness and sureness, as if it were a limb.”
—Sarah Bernhardt (1845–1923)
“I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.”
—Gottlob Frege (1848–1925)