Definition
A mandatory instruction sign, displayed as white characters on a red background, that marks the holding position on a taxiway before it enters a runway. The sign shows the runway designation (for example, '15-33') indicating the runway whose protected area begins at that point. An aircraft or vehicle must not cross the associated holding position marking onto the runway without an ATC clearance at a controlled airport.
Plain English
A red sign with white runway numbers placed beside the taxiway. It tells the pilot, 'Stop here. You are about to enter a runway. Do not go past this point without permission.'
Context Anchor
Seen while taxiing toward a runway, crossing a runway, or approaching a runway entrance from a taxiway.
Why Pilots Care
Crossing this sign without clearance can cause a runway incursion and create a serious collision risk with other aircraft or vehicles.
Analogy
It works like a stop sign for the runway boundary, but with aviation rules attached: the sign marks the line you do not cross until the runway side is approved and safe.
Intuition Check
Do not read “holding position” as a general waiting spot or parking place. Here it means a specific stop point at the edge of a runway area.
Example Sentence 1
Approaching the runway holding position sign for 27, the pilot stopped and held short until the tower issued a takeoff clearance.
Example Sentence 2
Ground control instructed the aircraft to hold at the runway holding position sign until the preceding departure cleared the runway.