The Flettner Fl 265 was an experimental

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 attributes ...

Anton Flettner Anton Flettner (November 1, 1885 – December 29, 1961) was a German aviation engineer and inventor. Born in Eddersheim (today a district of Hattersheim am Main), Flettner made important contributions to airplane, helicopter, vessel, and automob ...

Design and development

This helicopter, developed in 1938 with the support of

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

's ''

Kriegsmarine The (, ) was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war (1919–1935) of the Weimar Republic. The was one of three official branches, along with the a ...

'', made it possible, for the first time, to transition from powered rotary-wing flight to

autorotation Autorotation is a state of flight in which the main rotor system of a helicopter or other rotary-wing aircraft turns by the action of air moving up through the rotor, as with an autogyro, rather than engine power driving the rotor. Bensen, Igor ...

and back again, making it the safest helicopter of its time. In contrast to the Fl 185, the Fl 265, believed to be the pioneering example of a

synchropter Intermeshing rotors on a helicopter are a set of two rotors turning in opposite directions, with each rotor mast mounted with a slight angle to the other, in a transversely symmetrical manner, so that the blades intermesh without colliding. T ...

, had two intermeshing rotors 12 m in diameter, powered by a 160 hp (119 kW) BMW-Bramo Sh 14 A radial engine in the nose of the fuselage, fitted with a fan to assist cooling. Six helicopters were constructed, but series production was curtailed in favour of the

Flettner Fl 282 The Flettner Fl 282 ''Kolibri'' ("Hummingbird") is a single-seat intermeshing rotor helicopter, or ''synchropter'', produced by Anton Flettner of Germany. According to Yves Le Bec, the Flettner Fl 282 was the world's first series production heli ...

Operators

; *''

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

Specifications (Fl 265)

Notes

References

* Nowarra, Heinz J.: ''Die Deutsche Luftrüstung 1933-1945'', Bernard & Graefe Verlag, Koblenz 1993, *

External links