Many helicopters use tail rotors to counteract this force, while others feature multiple counter-rotating rotors which cancel out the torque forces, such as the 60-year-old CH-47 Chinook.

Without that tail rotor countering the torque, a single-rotor helicopter would spin in circles uncontrollably. Turboshaft engines also have a vital safety feature known as autorotation.

Because a helicopter's rotors need to produce a strong enough lift to move the vehicle, its contents, and fuel, those wash gusts flying under and outward from it are equally powerful.

Thus, rotorcraft — helicopters, autogyros, tiltrotors, etc. — have rotors, not propellers. The difference is not the orientation. It has to do with the mechanical design and function.

Early in the 1940s, the Hiller XH-44 would become the first helicopter to fly with rotors that were made exclusively of metal. This was in an attempt to keep them as strong as they needed to be ...

When rescue crews reached the passenger compartment of the helicopter that plunged into the Hudson River on Thursday, killing all six of its occupants, the aircraft was missing several critical ...