What action is necessary to make an aircraft turn?

To enable an aircraft to turn, it is essential to change the direction of lift. When an aircraft banks, the lift vector, which acts perpendicular to the wings, is tilted in the direction of the desired turn. This results in a horizontal component of lift that pulls the aircraft into the turn, allowing it to change direction effectively. The greater the bank angle, the more pronounced this effect becomes, enabling the aircraft to maneuver accurately in the desired direction.

The bank angle is critical because simply yawing the aircraft or changing the direction of thrust does not effectively change the path of flight. Although yawing can help with coordination, it does not generate the necessary lateral force to achieve a turn on its own. Similarly, while thrust can be redirected, it is the alteration in lift direction through banking that facilitates a controlled and efficient turn in aviation.