Which statement describes the flight characteristics of an aft center of gravity?

Which statement describes the flight characteristics of an aft center of gravity?

• A. Decrease stability, lower stall speed
• B. Increased longitudinal stability, higher stall speed
• C. Increased maneuverability, higher stall speed
• D. Decreased stall speed, increased stability

Answer: (A)

When the center of gravity is farther toward the tail, the airplane becomes less stable in pitch. The restoring tendency if the nose rises or falls is diminished, so small disturbances tend to be more exaggerated and the aircraft feels more “tippy” in flight. At the same time, the tail’s downforce is reduced, so to trim level flight the wing must carry more of the load at a higher pitch attitude. That puts the wing closer to its maximum lift coefficient during normal flight, so you reach the point where the wing can no longer provide enough lift at a lower airspeed. In practical terms, the stall can occur at a lower indicated airspeed when the CG is aft. This combination—reduced longitudinal stability and a tendency toward a lower stall speed—fits the statement described.

When the center of gravity is farther toward the tail, the airplane becomes less stable in pitch. The restoring tendency if the nose rises or falls is diminished, so small disturbances tend to be more exaggerated and the aircraft feels more “tippy” in flight.

At the same time, the tail’s downforce is reduced, so to trim level flight the wing must carry more of the load at a higher pitch attitude. That puts the wing closer to its maximum lift coefficient during normal flight, so you reach the point where the wing can no longer provide enough lift at a lower airspeed. In practical terms, the stall can occur at a lower indicated airspeed when the CG is aft.

This combination—reduced longitudinal stability and a tendency toward a lower stall speed—fits the statement described.