Backtrack

Backtrack refers to taxiing along a runway in the direction opposite to the intended takeoff or landing direction. This is necessary at airports where there is no taxiway to the threshold, or when a full-length takeoff is required.

ATC issues a backtrack clearance, and the pilot must vacate the runway as soon as the backtrack and lineup are complete. Common at smaller airports with a single runway and limited taxiway infrastructure.