If the loaded center of gravity is aft of the allowable range, what happens to pitch stability?

When the loaded center of gravity is positioned aft of the allowable range, pitch stability is reduced. The center of gravity is a critical factor in aircraft stability, particularly in the pitch axis. An aircraft is considered to have positive static stability when it tends to return to a level flight condition after being disturbed.

In instances where the center of gravity is relocated towards the tail of the aircraft—an aft center of gravity condition—there is a decrease in the aircraft's inherent pitch stability. This is because the center of lift, which generally acts at the wing's center, is now further in front of the center of gravity. Consequently, any nose-up pitch tendency is exacerbated, making the aircraft more difficult to correct and increasing the likelihood of a stall or loss of control.

Therefore, with the center of gravity aft of the allowable range, the aircraft becomes less stable in pitch, leading to a heightened criticality on pilot inputs to maintain controlled flight.