Transverse rotors

An MV-22B Osprey lands aboard the USS Iwo Jima (LHD-7).
Hanna Reitsch in Fw 61 V2
An Mil V-12 at Monino Central Air Force Museum (Moscow)

Transverse rotor rotorcraft have two large horizontal rotor assemblies mounted side by side.

Single rotor helicopters need a tail rotor to neutralize the twisting moment produced by the single large rotor. Tandem rotor helicopters, however, use counter-rotating rotors, with each canceling out the other's torque. Counter-rotating rotor blades won't collide with and destroy each other if they flex into the other rotor's pathway.

This configuration also has the advantage of being able to hold more weight with shorter blades, since there are two sets. Also, all of the power from the engines can be used for lift, whereas a single rotor helicopter uses power to counter the torque.

List of transverse rotor rotorcraft

Tranverse-mounted helicopters
Tranverse-mounted tiltrotors

See also