Some helicopters use contra-rotating coaxial rotors mounted one above the other.

The aircraft uses coaxial rotors and a 45 kW engine.

Coaxial rotors are two rotors mounted one above the other on the same axis.

Lift is provided by a set of coaxial rotors emanating from the waist of the system.

However, other design considerations plague coaxial rotors.

The configuration can also be used in helicopter designs termed coaxial rotors, where similar issues and principles of torque apply.

In 1946 his first helicopter, the Brantly B-1 with coaxial rotors made its first flight.

AVX Aircraft Company proposed a concept with coaxial rotors.

Coaxial rotors are a pair of rotors mounted one above the other on the same shaft and turning in opposite directions.

The Ka-10 was of similar layout to the Ka-8, with an open steel-tube structure carrying an engine, a pilot's seat and two three-bladed coaxial rotors.

Coaxial rotors solve the problem of angular momentum by turning each set of rotors in opposite directions.

Power was provided by a 240 HP Hispano radial engine which propelled the two contra-rotating, coaxial rotors.

This is commonly accomplished by a tail rotor, coaxial rotors, and recently the NOTAR systems.

Gyrodyne's design was an open-framework helicopter with coaxial rotors, which was evaluated with three different power plants (two reciprocating, one turbine).

The aircraft is fitted with trademark Kamov coaxial rotors, of advanced composite design, making the Ka-226 highly maneouverable and eliminating the need for a tail rotor.

In the late 1980s, Sikorsky Aircraft flew a small UAV named "Cypher", with coaxial rotors inside a torus-shaped airframe.

The Sikorsky X2 is an experimental high-speed compound helicopter with coaxial rotors developed by the American aircraft manufacturer Sikorsky Aircraft.

Coaxial rotors reduce the effects of dissymmetry of lift through the use of two rotors turning in opposite directions, causing blades to advance on either side at the same time.

The Manzolini Libellula II was an Italian 1950s experimental helicopter; its most notable feature was a pair of contra-rotating coaxial rotors that made the tail rotor unnecessary.

The Yakovlev EG (Eksperimentalnyi Gelikopter), also commonly known as the Yak-M11FR-1 and Sh (Shootka), was an experimental aircraft with coaxial rotors.

The company was not involved in gyrodyne development, but instead produced a turbine-engined, remotely-piloted drone helicopter, with coaxial rotors, for the United States Navy, designated as the QH-50 DASH.

Hungarian Kamov operators claim that coaxial rotors of the Ka-26 creates an airflow which allows pesticides to settle underneath, rather than on top of, the leaves, this means a much more effective distribution of pesticides, as most pests and parasites do not live on the top side of foliage.