What structural characteristic can create stability issues during flight?

Excessive rear weight load is a significant factor that can create stability issues during flight. In an aircraft, stability is heavily influenced by the distribution of weight, particularly in the longitudinal axis (fore-and-aft). When weight is concentrated excessively towards the rear of the aircraft, it results in a tail-heavy condition. This can affect the aircraft's center of gravity, moving it behind the optimal point for balanced flight.

A tail-heavy configuration can lead to poor handling characteristics, making the aircraft more susceptible to pitch instability. During various phases of flight, such as takeoff and landing, this instability can lead to difficulty in controlling the aircraft and increase the risk of stall conditions. Hence, maintaining an appropriate center of gravity within specified limits is critical for ensuring stability and controllability throughout the flight envelope.