Plain English Meaning

When you push the nose down too hard on the runway, the front wheel ends up carrying most of the weight and the back wheels barely touch. The airplane then handles like a wobbly wheelbarrow -- hard to steer, hard to slow down, and prone to swerving off the runway.

Full Definition

A loss of directional control on the runway in a nosewheel airplane caused when most of the weight shifts onto the nosewheel and the main wheels carry little or no weight. With the mains unloaded, their stabilizing friction is reduced, the airplane becomes difficult to steer, brakes lose effectiveness, and the airplane can swerve, skid sideways, or depart the runway. It typically occurs during landing rollout or takeoff when forward pressure on the elevator control is held while too fast or with excess on the .