Loading an airplane to the most aft CG will cause the airplane to be:

• A. Less stable at all speeds
• B. More stable at all speeds
• C. Have higher climb rate
• D. Have lower stall speed

Answer: (A)

The key idea is how the center of gravity position affects longitudinal stability. Longitudinal stability comes from the balance between the aircraft’s weight distribution and the tail’s restoring moment. When the CG is ahead of the neutral point, any pitch disturbance tends to be damped and the airplane tends to return to level flight. Move the CG toward the rear, toward the neutral point and beyond, and that restoring capability diminishes. At the most aft positions, the tail’s stabilizing effect is reduced, making the aircraft more responsive to disturbances in pitch and more prone to diverging motion rather than damping it. In other words, the airplane becomes less stable across speeds.

Climb performance isn’t primarily set by CG position, but by weight and power available, so an aft CG doesn’t inherently give a higher climb rate. Stall speed is governed mainly by weight and wing characteristics (and how high the aircraft can reach the required angle of attack), so moving the CG rearward doesn’t systematically lower stall speed.