The Focke-Wulf Fw 61 is often considered the first practical, functional

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribut ...

, first flown in 1936. It was also known as the Fa 61, as Focke began a new company— Focke-Achgelis—in 1937.

Design and development

DBP 1979 1008 Jugendmarke Focke-Wulf FW 61 1936

Professor Henrich Focke, through his development of the Fw 186, and through the efforts of producing the C.19 and C.30 autogyros under licence, came to the conclusion that the limitations of autogyros could be eliminated only by an aircraft with a powered rotor, 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 The Deutsches Museum (''German Museum'', officially (English: ''German Museum of Masterpieces of Science and Technology'')) in Munich, Germany, is the world's largest museum of science and technology, with about 28,000 exhibited objects from ...

Munich Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and Ha ...

. On 9 February 1935, Focke received an order for the building of a prototype, which was designated the Fw 61; 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 The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system. Airframe design is a field of aero ...

was based on that of a well-tried training aircraft, the Focke-Wulf Fw 44 ''Stieglitz''. Using rotor technology licensed from the Cierva Autogiro Company, a single

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

drove twin rotors, set on tubular steel outriggers to the left and right of the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

. Each main rotor consisted of three articulated and tapered blades, driven by the engine through gears and shafts. Longitudinal and directional control was achieved using cyclic pitch and asymmetric rotor lift. The

counter-rotation Rotation, or spin, is the circular movement of an object around a '' central axis''. A two-dimensional rotating object has only one possible central axis and can rotate in either a clockwise or counterclockwise direction. A three-dimensional ...

of the two rotors solved the problem of

torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...

-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 and 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 early 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. Focke-Achgelis began work on a two-seat sports version of the Fw 61, the ''Fa 224'', which would have used an Argus As 10C engine and had greater performance. However, the Fa 224 never left the drawing board at the outbreak of World War II.

Operational history

In February 1938, the Fw 61 was demonstrated by Hanna Reitsch indoors at the ''

Deutschlandhalle Deutschlandhalle was an arena located in the Westend neighbourhood of Berlin, Germany. It was inaugurated on 29 November 1935 by Adolf Hitler. The building was granted landmark status in 1995, but was demolished on 3 December 2011. History Built ...

'' sports stadium in Berlin, Germany.Ruffin 2005, p. 19. It subsequently set several records for

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

speed In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity ...

and flight duration culminating, in June 1938, with an altitude record of 3,427 m (11,243 ft), breaking the unofficial altitude record of the

TsAGI 1-EA The Central Aerohydrodynamic Institute (also (Zhukovsky) Central Institute of Aerodynamics, russian: Центра́льный аэрогидродинами́ческий институ́т, ЦАГИ, Tsentral'nyy Aerogidrodinamicheskiy Institut, ...

single lift-rotor helicopter from the Soviet Union set in August 1932, and a straight line flight record of 230 km (143 mi). Neither of these machines appear to have survived

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, although a replica is on display at the Hubschraubermuseum in

Bückeburg Bückeburg ( Northern Low Saxon: ''Bückeborg'') is a town in Lower Saxony, Germany, on the border with North Rhine Westphalia. It is located in the district of Schaumburg close to the northern slopes of the Weserbergland ridge. Population: 21 ...

, Germany.

Specifications (Fw 61)

References

Notes

Bibliography

* Coates, Steve and Jean-Christophe Carbonel. ''Helicopters of the Third Reich''. Crowborough, UK: Classic Publications Ltd., 2002. . * Green, William. Aircraft of the Third Reich, Vol.1''. London: Aerospace Publishing Limited, (First ed.) 2010. . * Nowarra, Heinz J. ''German Helicopters, 1928–1945''. Atglen, Pennsylvania: Schiffer Publishing, 1990. . * Ruffin, Steven A. Aviation's Most Wanted: The Top 10 book of Winged Wonders, Lucky Landings and Other Aerial Oddities. Washington D.C.: Potomac Books, 2005. . * Smith, J. Richard. ''Focke-Wulf, an Aircraft Album''. London: Ian Allan Ltd., 1973. . * Smith, J. Richard and Anthony Kay. ''German Aircraft of the Second World War''. London: Putnam & Company Ltd., 1972 (3rd edition 1978). . * Witkowski, Ryszard. ''Rotorcraft of the Third Reich''. Redbourn, UK: Mushroom Model Publications, 2007. .

External links

French & German Helicopter Pioneers (Fa 61)

Focke Wulf Fw 61 luftwaffe
at YouTube
Vertical Rewind: Spoils of WarArchive
{{Use dmy dates, date=May 2019 1930s German experimental aircraft Military helicopters World War II helicopters of Germany Fw 061 1930s German helicopters Transverse rotor helicopters Single-engined piston helicopters Aircraft first flown in 1936