Stop Bar
A line of red lights embedded in a taxiway at a runway holding position, controlled by ATC to indicate when an aircraft must stop.
Full Definition
A stop bar is a row of unidirectional red lights installed across a taxiway at the runway holding position, used in conjunction with taxiway centreline lighting to regulate the entry of aircraft onto runways, particularly in low-visibility conditions. When illuminated, a stop bar requires all aircraft and vehicles to halt. Stop bars are controlled by air traffic control and are a key element of runway incursion prevention systems. Editors should be careful not to confuse stop bars with the painted runway holding position markings, which are separate but co-located features.
Usage
Usage note: Hyphenate as 'stop bar' (two words, no hyphen). Distinguish from the painted bar markings; the stop bar specifically refers to the lighting system.
In Context
- "The stop bar at holding point Alpha was activated as the departing aircraft rotated." — Runway safety procedures manual
- "Stop bars must be operational at all runway holding positions during Category II and III operations." — Airport low-visibility procedures document