Radius of Turn
From SKYbrary Wiki
The horizontal distance that an aircraft uses to turn is referred to as the radius of turn. It varies as a function of bank angle and the square of the airspeed.
Radius of turn is dependent on both airspeed and bank angle. The radius of turn at any given bank angle is directly proportional to the square of the airspeed. Doubling the airspeed results in a radius of turn that is four times greater while tripling the airspeed would result in a radius that is nine times greater. Conversely, if the aircraft speed remains constant, increasing the bank angle will decrease the turn radius.
These relationships are the opposite of those found in Rate of Turn where increasing the speed decreases the rate of turn and increasing bank angle also increases the rate of turn.