What is the primary reason CG must stay within specified limits?

• A. To improve fuel efficiency.
• B. To minimize cabin noise.
• C. To maximize baggage space.
• D. To ensure stability and controllability; outside limits may make the airplane hard to control or stall.

Answer: (D)

The main idea is that where the weight is placed inside the airplane (the center of gravity) fixes how the airplane behaves in pitch and how much elevator authority you have. Keeping the CG within limits keeps the aircraft's stability and controllability predictable across different flight conditions. If the CG is too far forward, the airplane becomes more nose-stable but harder to pitch up; the elevator may not have enough authority to raise the nose or recover from a stall or from a high-pitch situation. If the CG is too far aft, the aircraft can become unstable and rescue from stalls or spins can be difficult because the tail may no longer provide enough restoring moment. In short, staying within CG limits ensures safe, controllable handling and reliable stall behavior. The other options focus on factors like fuel efficiency, cabin noise, or baggage space, which are not the primary safety-related reason for CG limits.