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Intermeshing-rotor helicopter

Helicopter with two rotors turning in opposite directions

You can help expand this article with text translated from the corresponding article in German. (June 2015) Click [show] for important translation instructions. View a machine-translated version of the German article. Machine translation, like DeepLorGoogle Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 1,897 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing German Wikipedia article at [[:de:Flettner-Doppelrotor]]; see its history for attribution. You may also add the template {{Translated|de|Flettner-Doppelrotor}} to the talk page. For more guidance, see Wikipedia:Translation.

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Anintermeshing-rotor helicopter (orsynchropter) is a helicopter with a set of two main 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. The arrangement allows the helicopter to function without a tail rotor, which saves power. However, neither rotor lifts directly vertically, which reduces efficiency per each rotor.

Yaw is accomplished through varying torque, which is done by increasing collective pitch on one of the blade sets.

Most intermeshing designs have two blades per mast, although exceptions such as the Kellett XR-10 with three blades per mast do exist.

The arrangement was developed in GermanybyAnton Flettner for a small anti-submarine warfare helicopter, the Flettner Fl 265 as the pioneering example, and later the Flettner Fl 282 Kolibri.^[1] During the Cold War the American Kaman Aircraft company produced the HH-43 Huskie, for USAF firefighting purposes. One example of the Kaman K-225 experimental synchropter was fitted with a small turboshaft engine in late 1951, becoming the world's first gas turbine-powered helicopter. Intermeshing rotored helicopters have high stability and powerful lifting capability. The latest Kaman K-MAX model is a dedicated sky-crane design used for construction work, and has been modified for trials by the USMC as an optionally-unmanned cargo transporter. Unmanned aerial vehicles with intermeshing rotors have also been flown.^[2]

Examples[edit]

• Flettner Fl 265 (1939)
• Flettner Fl 282 (1941)
• Kellett XR-8 (1944)
• Kaman K-225 (1947)
• Kellett XR-10 (1947)
• Praga E-1 (1947)
• SNCAC NC.2001 Abeille (1949)
• Kaman HH-43 Huskie (1953)
• Kaman K-700 (1969) (abandoned)
• Clybouw CW-105F (1973)
• DeGraw RDX1091 Hummingbird (1984)
• Kaman K-MAX (1991)

See also[edit]

• Coaxial-rotor helicopter
• Tandem-rotor helicopter
• Transverse-rotor helicopter

References[edit]

External links[edit]

• Media related to Intermeshing-rotor helicopters at Wikimedia Commons

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