How is stall speed affected by weight?

Stall speed is defined as the minimum speed at which an aircraft can maintain controlled flight. It is influenced primarily by the weight of the aircraft. As the weight of the aircraft increases, the stall speed also increases. This relationship is due to the need for greater lift to support the heavier load.

When the aircraft's weight increases, additional lift is required to counteract this weight. Since lift is generated as a function of airspeed, wing area, and the lift coefficient, a higher airspeed is needed to create sufficient lift at a heavier weight. Therefore, to avoid stalling, the pilot must maintain a higher airspeed, which corresponds to a higher stall speed.

In contrast, if the weight of the aircraft were to decrease, the stall speed would decrease as well because the amount of lift required to remain airborne would be lower. This reflects the direct relationship between weight and stall speed, where higher weight results in a higher stall speed.

The other options do not align with this principle: the stall speed does not remain constant irrespective of weight, nor does it solely change based on altitude. Stall speed is primarily affected by weight, making the understanding of this relationship crucial for safe flight operations.