What happens if the center of gravity is too far aft on a fixed-wing aircraft?

What happens if the center of gravity is too far aft on a fixed-wing aircraft?

• A. A flat spin may develop
• B. The aircraft will become more stable
• C. The takeoff distance will increase
• D. The aircraft will pitch down

Answer: (A)

When the center of gravity (CG) is positioned too far aft on a fixed-wing aircraft, it can lead to a condition known as a flat spin. A flat spin occurs when the aircraft becomes uncontrollable and can rotate rapidly around its vertical axis. In this situation, the aircraft's stability decreases significantly, making it difficult for the pilot to regain control.

An overly rearward CG compromises the aircraft's ability to pitch down effectively, as the tail may have insufficient control authority to counteract the pitching moments generated by the wings during flight. This lack of control can manifest in various adverse flight characteristics, particularly during maneuvers such as stall recovery or aggressive turns. Eventually, this can result in a flat spin, which poses significant safety risks.

The other options do not align with the aerodynamic principles governing flight. An aft CG decreases stability, not increases it; it does not directly lead to increased takeoff distance; and rather than pitching down, an aft CG typically results in a tendency for the aircraft to pitch up or become unresponsive altogether.