Private Pilot License (PPL) Aerodynamics Practice Exam

What force is primarily responsible for making an airplane turn?

1. The horizontal component of lift

2. Gravity acting on the aircraft

3. Friction from the tires on the runway

4. Thrust generated by the engines

The correct answer is: The horizontal component of lift

The primary force responsible for making an airplane turn is the horizontal component of lift. When an aircraft is in flight, the wings generate lift that acts perpendicular to the relative wind. By banking the aircraft, the lift vector tilts, and this causes a portion of the lift to act horizontally, providing the necessary centripetal force that facilitates the turn. This horizontal lift component redirects the aircraft's path without changing its altitude, allowing it to maneuver in the desired direction. Effective turning also requires an appropriate angle of bank to maintain the lift and control the turn rate, making this horizontal component crucial for aircraft maneuverability. While gravity also plays a role in overall flight dynamics and friction from tires is important for ground handling, neither contributes to the actual turning motion in the air. Thrust is essential for forward motion but does not directly influence the turn. Understanding the role of the horizontal component of lift is fundamental in mastering basic aerodynamics for flight.