Intermeshing rotors on a

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 ...

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. 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. This configuration is sometimes referred to as a synchropter. 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

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

by Anton Flettner for a small

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typi ...

helicopter, the Flettner Fl 265 as the pioneering example, and later the

Flettner Fl 282 Kolibri 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 hel ...

. During the Cold War the American

Kaman Aircraft Kaman Corporation is an American aerospace company, with headquarters in Bloomfield, Connecticut. It was founded in 1945 by Charles Kaman. During the first ten years the company operated exclusively as a designer and manufacturer of several he ...

company produced the HH-43 Huskie, for

USAF The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...

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 A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...

-powered helicopter. Intermeshing rotored helicopters have high stability and powerful lifting capability. The latest

Kaman K-MAX The Kaman K-MAX (company designation K-1200) is an American helicopter with intermeshing rotors (synchropter) by Kaman Aircraft. It is optimized for external cargo load operations, and is able to lift a payload of over , which is more than the ...

model is a dedicated sky-crane design used for construction work, and has been modified for trials by the

USMC The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through co ...

as an optionally-unmanned cargo transporter.

Unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controlle ...

s with intermeshing rotors have also been flown.

List of intermeshing rotor helicopters

* 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 The SNCAC NC.2001 Abeille ( en, Bee) was a single engine, twin intermeshing rotor helicopter designed and built in France in the late 1940s. Three were completed but only one flew, development ending when SNCAC was closed. Design and developmen ...

(1949) * Kaman HH-43 Huskie (1953) * Kaman K-700 (1969) (abandoned) * Clybouw CW-105F (1973) * DeGraw RDX1091 Hummingbird (1984) *

(1991)

References

External links

* Rotorcraft Helicopter components {{Component-aircraft-stub

List of intermeshing rotor helicopters

See also

References

External links