When an airplane is loaded to the most aft center of gravity (CG), what is likely to happen?

When an airplane is loaded to the most aft center of gravity (CG), it becomes less stable at all speeds. The center of gravity is a crucial factor in determining an aircraft's stability and performance. When the CG is positioned towards the rear, or aft, of the aircraft, it negatively affects the stability of the airplane.

A more aft CG position tends to reduce the effectiveness of the horizontal stabilizer, which is responsible for providing stability in pitch. This configuration can make the aircraft more susceptible to uncontrollable pitch changes and can cause difficulty in recovering from maneuvers or stalls. Essentially, the aircraft may feel more "twitchy" and less equipped to respond predictably to control inputs.

Additionally, stability in flight is integral to safety; when the CG is too far back, it can lead to issues such as uncontrollable nose-up attitudes or difficulty in maintaining level flight, especially during critical phases of flight like takeoff and landing. Thus, loading the airplane to an aft CG increases the risk of undesirable flight characteristics, making it less stable across all speeds.