The idea of a machine that could fly from a vertical takeoff was first mooted by Leonardo da Vinci as far back as the early 1480s. Over the next four hundred years or so, inventors, engineers, and aviation pioneers developed the idea of a rotocraft, in which lift and thrust are supplied by horizontally-spinning rotors. The first modern helicopters appeared in the late 1930s, and today they are a familiar sight in skies around the world. More recently, the advent of the quadcopter, often referred to as a drone, has seen da Vinci's original concept come full circle.
Intrigued? Click through the following gallery for a brief look at the history of the helicopter.