Displaced Thresholds

On some occasions, natural and human-made obstacles penetrate the obstacle limitation surface of the approach paths to runways. To ensure that a safe clearance from these obstacles is maintained, it is sometimes necessary to displace the threshold upwind from the adjacent runway end where the approach slope cannot be raised. The portion of the runway behind a displaced threshold is available for takeoffs in either direction and landings from the opposite direction. A 10 ft wide white threshold bar is located across the width of the runway at the displaced threshold. White arrows are located along the centerline in the area between the beginning of the runway and the displaced threshold. In the case of a temporary displacement white arrow heads are located across the width of the runway just prior to the threshold bar.