Configurations of Rotary-Wing Aircraft

in Aerodynamics, Aircraft Assembly, and Rigging

Autogyro

An autogyro is an aircraft with a free-spinning horizontal rotor that turns due to passage of air upward through the rotor. This air motion is created from forward motion of the aircraft resulting from either a tractor or pusher configured engine/propeller design. [Figure 2-24]

Figure 2-24. An autogyro.

Figure 2-24. An autogyro.

Single Rotor Helicopter

An aircraft with a single horizontal main rotor that provides both lift and direction of travel is a single rotor helicopter. A secondary rotor mounted vertically on the tail counteracts the rotational force (torque) of the main rotor to correct yaw of the fuselage. [Figure 2-25]

Figure 2-25. Single rotor helicopter.

Figure 2-25. Single rotor helicopter.

Dual Rotor Helicopter

An aircraft with two horizontal rotors that provide both the lift and directional control is a dual rotor helicopter. The rotors are counterrotating to balance the aerodynamic torque and eliminate the need for a separate antitorque system. [Figure 2-26]

Figure 2-26. Dual rotor helicopter.

Figure 2-26. Dual rotor helicopter.