P-factor is a force that causes the airplane to do what?

P-factor, also known as asymmetric propeller loading, is a phenomenon that occurs particularly during climb and requires an understanding of how propeller blades interact with air. When an airplane with a conventional propeller is operating at a high angle of attack, the descending blade (the right side for most propeller configurations in single-engine aircraft) generates more thrust than the ascending blade (the left side). This discrepancy in thrust creates a yawing motion, causing the aircraft to turn to the left.

This is particularly evident in single-engine aircraft where the propeller's rotation direction plays a significant role in generating unequal thrust between the left and right sides of the airplane. Therefore, understanding P-factor is crucial for pilots, especially during critical phases of flight such as takeoff and climb, where maintaining directional control is essential.

Given this understanding, the answer identifying the yawing effect to the left is accurate due to the asymmetrical forces produced by the propeller.