Plain English Meaning

When the airplane's nose is pitched up and the engine is producing high power, one side of the propeller bites into the air harder than the other. This uneven pull tugs the nose of the airplane to one side, usually to the left.

Full Definition

P-factor is the yawing tendency caused by the descending propeller blade producing more thrust than the ascending blade when the airplane is flown at a high angle of attack. On a typical single-engine airplane with a propeller rotating clockwise as viewed from the cockpit, the descending blade is on the right side, so the airplane yaws to the left. P-factor becomes most noticeable during high-power, high angle-of-attack flight conditions such as , , and .