What is the relationship between static stability and dynamic stability in aircraft?

Static stability refers to the initial tendency of an aircraft to return to its original position after being disturbed, whereas dynamic stability describes how an aircraft behaves over time after that disturbance. For dynamic stability to be established, there must be some form of static stability present. If an aircraft has positive static stability, it means that after a disturbance, it will initially respond by returning toward its original flight path. This positive initial response allows for a progressive return to the original position over time, thereby establishing dynamic stability.

In contrast, if an aircraft lacks positive static stability—meaning it tends to move further away from its original position after being disturbed—it cannot achieve dynamic stability. Hence, the presence of positive static stability is a prerequisite for dynamic stability to manifest. This relationship underscores the importance of both stability concepts in ensuring safe and predictable aircraft behavior during flight.