displaced threshold

A runway threshold moved down the paved surface, so the pavement before it may be taxied on but not landed on.

Thresholds are displaced for obstacle clearance on the approach or for noise. The unusable portion is marked with arrows leading to a solid bar. It matters to a spotter because touchdown happens further along the runway than the pavement suggests, which moves the best vantage point.

Nearby in Aviation

de-icing — Spraying an aircraft with heated fluid to remove frost, ice or snow before departure, and to delay its return.
deadhead — A crew member travelling as a passenger to get into position for a duty.
diversion — A flight that lands somewhere other than its planned destination.
DME — A radio system that tells an aircraft its slant distance from a ground beacon.