Fastest single-rotor helicopter
The fastest single-rotor helicopter in the world is said to be what sources call a “slightly modified” Westland Lynx ZB500. No specifics were given regarding the modifications but this particular helicopter reached a speed of over 249 mph or 400 km/h at an air show in Europe on August 6, 1986. In comparison to some of the other vehicles and/or machines on this list that speed may not be very impressive.
However, research has shown that “the the maximum speed” a single-rotor helicopter can theoretically reach before it spins out of control and crashes is approximately 250 mph. This means that the customized helicopter in question is actually the world’s fastest helicopter if for no other reason than it could reach 250 mph and still maintain its course.
(Image courtesy of HMFriends)