If the center of gravity is aft of the recommended limit, what stabilization and stall characteristics are most likely?

• A. Decreased longitudinal stability and elevator effectiveness; stalls may be more abrupt.
• B. Increased longitudinal stability and elevator effectiveness; stalls less abrupt.
• C. No change in stability.
• D. Only stall speed changes.

Answer: (A)

Pitched stability and elevator control are affected by where the weight sits relative to the wing’s aerodynamic center. When the center of gravity is toward the tail, the airplane becomes less stable in pitch because the restoring moment that tends to bring the nose back down after a disturbance is weakened. That reduced stability means a small pitch disturbance can grow more easily rather than be damped out.

At the same time, tail-down force and the elevator’s ability to produce the needed pitch moment are less effective, especially near stall when wing downwash and flow changes diminish tail authority. The result is that the aircraft can be more difficult to control in pitch and stalls can develop more abruptly, with less warning and a sharper break.

So, an aft CG leads to decreased longitudinal stability and reduced elevator effectiveness, and stalls tending to be more abrupt.