What effect does increasing the weight of an aircraft have on its flight characteristics?

Increasing the weight of an aircraft fundamentally alters its flight characteristics, primarily by increasing the amount of lift required for level flight. A heavier aircraft has more mass, which means that for the aircraft to fly safely and effectively, it must generate additional lift to counteract the increased gravitational force acting on it.

This requirement for more lift directly influences stall speed. Stall speed is the minimum airspeed at which an aircraft can maintain level flight; it increases with weight. Since a heavier aircraft needs to maintain a higher lift coefficient to remain in the air, it must fly at higher speeds. Consequently, as the aircraft's weight increases, the stall speed rises, meaning the pilot must be more vigilant about speed management, especially during critical phases of flight like takeoff and landing.

Additionally, increased weight generally has implications for drag, maneuverability, and overall performance. While some might think increased weight could enhance maneuverability, it typically results in reduced performance in terms of the aircraft's responsiveness to control inputs, especially during turns. Therefore, the correct interpretation of the effect of increased weight on flight characteristics points clearly to the necessity for more lift and the associated increase in stall speed.