Plain English Meaning

Early in the takeoff roll, the rudder pedals don't yet have enough air moving over them to steer the airplane on their own, so the pilot has to combine pedal input with ground steering until the airplane is moving fast enough for the rudder to do the job by itself.

Full Definition

A condition during the takeoff roll in which the rudder is not yet fully effective for directional control because airflow over its surface is still too low. The pilot must supplement rudder input with steering from the nosewheel or tailwheel until the airplane gains enough speed for the rudder alone to keep the airplane straight.

Context Anchor

Encountered during instrument takeoff , especially while the and during the first part of the takeoff roll.