Plain English Meaning

When the load in the airplane is shifted too far forward or too far back, the airplane tends to tip nose-down or tail-down, and the tail has to work harder to keep it flying level.

Full Definition

A condition in which the distribution of weight along the aircraft's longitudinal (nose-to-tail) axis causes the airplane to be nose-heavy or tail-heavy, requiring the horizontal tail surfaces to produce a corrective force to maintain level flight.

Context Anchor

Seen in discussions, especially when checking whether the loaded airplane will within its forward and aft limits.