What is the effect of having the center of gravity (C of G) at the most aft limit in an aircraft?

What is the effect of having the center of gravity (C of G) at the most aft limit in an aircraft?

• A. It increases longitudinal stability
• B. It decreases longitudinal stability about the lateral axis
• C. It has no effect on stability
• D. It improves the aircraft's maneuverability

Answer: (B)

When the center of gravity (C of G) is positioned at the most aft limit in an aircraft, it decreases longitudinal stability about the lateral axis. This is because placing the C of G further aft moves it closer to the aircraft's aerodynamic center, where the forces acting on the aircraft balance. In this configuration, the aircraft requires less control input to change its pitch attitude, but it also becomes more sensitive to disturbances. As a result, if the aircraft experiences a pitch-up or pitch-down motion, it will be less effective in returning to a stable attitude without pilot intervention. This sensitivity reduces stability, potentially leading to difficulty in controlling the aircraft, especially during maneuvers. Thus, aft loading of the C of G can lead to a less stable condition requiring more careful handling and control inputs.

When the center of gravity (C of G) is positioned at the most aft limit in an aircraft, it decreases longitudinal stability about the lateral axis. This is because placing the C of G further aft moves it closer to the aircraft's aerodynamic center, where the forces acting on the aircraft balance. In this configuration, the aircraft requires less control input to change its pitch attitude, but it also becomes more sensitive to disturbances. As a result, if the aircraft experiences a pitch-up or pitch-down motion, it will be less effective in returning to a stable attitude without pilot intervention. This sensitivity reduces stability, potentially leading to difficulty in controlling the aircraft, especially during maneuvers. Thus, aft loading of the C of G can lead to a less stable condition requiring more careful handling and control inputs.