Turn radius and rate of turn

Published by PilotDeskSources, testing & corrections

In a coordinated level turn, bank angle and true airspeed determine both how tightly the airplane turns and how quickly its heading changes. Understanding the relationship helps explain standard-rate turns, maneuvering geometry and why high-speed aircraft need more room.

Speed has a strong effect on radius

For the same bank angle, increasing true airspeed increases turn radius. The effect is not merely linear: turn radius grows roughly with the square of speed, so doubling speed produces a much larger circle.

More bank tightens the turn

Increasing bank angle increases the horizontal component of lift and decreases turn radius, assuming altitude and coordination are maintained. It also increases load factor, which affects stall speed.

Rate of turn

Rate of turn describes heading change per unit time, commonly degrees per second. At a given speed, more bank produces a faster rate of turn. At a given bank, higher speed produces a slower rate.

Standard rate

A standard-rate turn is approximately 3 degrees per second, or a full 360-degree turn in about two minutes. The bank angle needed for that rate increases as true airspeed increases.

Use true airspeed in aerodynamic geometry

Turn-radius and coordinated-turn equations are generally based on true airspeed. Using indicated airspeed without considering altitude and temperature can distort the estimate, especially at higher altitudes.

Real turns are not perfect equations

Wind changes the ground track, turbulence can change bank or speed, and pilots may not hold altitude or coordination exactly. The calculator models idealized coordinated flight rather than predicting a precise path over the ground.

Related PilotDesk guides

Standard-rate turns · Load factor · TAS estimate