What happens to the stall speed as weight increases?

As weight increases, the stall speed increases. This relationship is rooted in the principles of aerodynamics and the physics that govern flight.

Stall speed is defined as the minimum speed at which an aircraft can maintain level flight. As the weight of the aircraft increases—whether due to additional passengers, cargo, or fuel—the wings must generate more lift to counteract that increased weight. Lift is produced based on the equation that relates lift force to airspeed, wing area, and the coefficient of lift, which is affected by the angle of attack.

When weight rises, the aircraft requires a higher angle of attack to produce sufficient lift for that additional weight. As airspeed decreases toward stall speed, the angle of attack approaches the critical angle of attack sooner at higher weights. Consequently, the stall speed must increase to avoid reaching that critical angle of attack at lower airspeeds.

Therefore, an increase in weight leads to an increase in stall speed, reinforcing the concept that pilots need to be aware of weight impacts when flying, especially during maneuvers where low speeds are involved.