Under what flight condition does P-factor cause the airplane to yaw to the left?

P-factor, or propeller-induced yaw, occurs when the angle of attack becomes significant, typically at high angles of attack. This aerodynamic phenomenon arises from the different effective angles of attack on the propeller blades as the aircraft pitches up, often during climbs or steep turns.

In a standard configuration, the descending blade on the right side of the propeller generates more thrust than the ascending blade on the left side. When the angle of attack increases, this difference in thrust becomes more pronounced, causing the airplane to yaw to the left. This is particularly relevant during maneuvers that approach or exceed critical angles of attack, such as in climb-out or steep turns. Thus, high angles of attack are directly associated with the tendency of the aircraft to yaw left due to P-factor.

In contrast, conditions like cruising altitude, landing approaches, and stable flight typically involve lower angles of attack, where P-factor is less significant and does not notably affect the yaw of the aircraft.