Define center of gravity and explain why it must lie within approved limits.

• A. CG is the point where weight acts; within limits ensures stable handling and elevator authority.
• B. CG is the average of wing lift; within limits ensures maximum glide ratio.
• C. CG is the center of lift; within limits ensures autopilot functionality.
• D. CG is the engine thrust center; within limits ensures takeoff speed.

Answer: (A)

The center of gravity is the point along the aircraft’s longitudinal axis where the total weight can be considered to act—the balance point of the airplane. Keeping the CG within approved limits ensures stable handling and adequate elevator authority. When the CG is too far forward, the airplane becomes more statically stable but the elevator loses effectiveness, making rotation on takeoff harder and pitch control heavier. If the CG is too far aft, stability is reduced and the aircraft can become difficult to control, especially in stalls or aggressive maneuvers. The published CG range is chosen to keep these handling qualities predictable and to keep structural loads within design limits, which is why defining the CG as the weight-acting point and requiring it to stay within limits is the correct concept.