During takeoff, what tendency does the airplane exhibit?

During takeoff, an airplane typically exhibits a tendency to turn to the left. This is primarily due to a combination of several aerodynamic and engine factors.

One of the key reasons for this left-turning tendency is the phenomenon known as "P-factor," which occurs when the aircraft is at a high angle of attack. The downward-moving blade of the propeller generates more thrust than the upward-moving blade, resulting in a yawing motion to the left. Additionally, the asymmetric thrust caused by this effect, combined with the torque produced by the engine (which also tends to roll the airplane in the opposite direction of the propeller rotation), contributes to the left turn.

Another contributing factor is the spiral slipstream created by the propeller, which wraps around the fuselage and strikes the vertical stabilizer (tail fin), also exerting a force that causes the aircraft to yaw left.

Understanding this tendency is crucial for pilots when managing directional control during takeoff, particularly in single-engine planes, where addressing this left-turn tendency is essential for a safe and effective takeoff roll.