Why a car can overtake a helicopter

In the epic speed competition between what travels and flies, we tend to unconditionally give up aviation leadership for one simple reason - less air resistance. But physics is a funny thing, fraught with unexpected paradoxes. Consider, for example, the speed capabilities of a helicopter and a car.

The helicopter is lifted off the ground when the lift of the blades exceeds its own weight. As soon as these indicators equalize, the helicopter hovers in the air.

To start moving forward, the pilot activates the swashplate - the rotor control mechanism. It changes the pitch and roll of the helicopter by creating a difference in the lifting forces of the rotor blades. As the incline increases, the angle of attack and lift increases.

However, at some point (at a speed of about 400 km / h), the helicopter reaches the so-called flow separation boundary, when the amplitude of the propeller's oscillatory movements reaches a limit, which can lead to a stall of the flow from the tips of the blades.

Unlike a helicopter, the car also has enough aerodynamic problems, but at the same time there is no hard limit for the type of flow separation boundary for it, so it is not surprising that the development of the Bloodhound SSC supersonic vehicle, capable of reaching a theoretical speed of 1610 km / h, has been ongoing for several years.