What are clearance bars?
A row of at least three in-pavement, steady-burning yellow lights installed across a taxiway to increase the conspicuity of a holding position or a geometrically complex taxiway intersection. Its ICAO Annex 14 equivalent is intermediate holding position lights.
A clearance bar is a row of at least three in-pavement, steady-burning yellow lights installed across a taxiway. Its job is narrow and specific: to increase the conspicuity of a particular holding position or of a taxiway intersection whose geometry is complex enough that a pilot could otherwise lose track of the intended route — for example where several taxiways converge, or where the intended path curves sharply through the intersection.
A clearance bar can look like a stop bar at a glance, because both are a row of in-pavement lights across the taxiway, but they differ in colour and purpose. A stop bar is red and is switched off to give an aircraft clearance to cross; it is normally at a runway-holding position, and sometimes at an intermediate holding position. A clearance bar is steady yellow and does not work as a crossing clearance signal. It is a conspicuity aid that makes one point on the taxiway centreline stand out, and it may mark the location of an intermediate holding position. Whether an aircraft holds or proceeds is decided by the ATC instruction and the markings, not by the bar alone.
Terminology. “Clearance bar” is the term used in FAA practice (AC 150/5340-30). ICAO Annex 14 covers the equivalent as intermediate holding position lights: three fixed, unidirectional yellow lights, 1.5 m apart, set symmetrically about and at right angles to the taxiway centreline, 0.3 m before the intermediate holding position marking. See Entry 13.
Clearance Bars: Key Points
A clearance bar is a row of at least three steady-burning yellow in-pavement lights across a taxiway centreline, used to make a holding position or a complex intersection conspicuous. It is not a stop bar: a stop bar is red and is switched off to give clearance, while a clearance bar is not a crossing-clearance signal, and the ATC instruction decides whether the aircraft holds or proceeds. Clearance bar is the FAA term. ICAO Annex 14 covers the equivalent as intermediate holding position lights: three fixed, unidirectional yellow lights, 1.5 m apart, 0.3 m before the intermediate holding position marking. Confirm the layout against your regulator’s standard. See Taxiway Centreline Lights.
Frequently Asked Questions
Q1What is a clearance bar in AGL terms?
A row of at least three in-pavement, steady-burning yellow lights installed across a taxiway to increase the conspicuity of a holding position or a geometrically complex taxiway intersection. Clearance bar is the FAA term; ICAO Annex 14 covers the equivalent as intermediate holding position lights.
Q2How is a clearance bar different from a stop bar?
A stop bar is a red light array that is switched off to give an aircraft clearance to cross, normally at a runway-holding position. A clearance bar is steady yellow and is not a crossing-clearance signal: it is a conspicuity aid for a holding position or a complex intersection, and the ATC instruction decides whether the aircraft holds or proceeds.
Q3How many lights make up a clearance bar, and what colour are they?
At least three lights, yellow, arranged in a row across the taxiway centre line, flush-mounted and steady-burning.
Q4Can a clearance bar mark an intermediate holding position?
Yes. In addition to flagging a complex intersection, a clearance bar may also be used to indicate the location of an intermediate holding position.
Q5Is clearance bar an ICAO term?
Not as such. Clearance bar is the FAA term (AC 150/5340-30). ICAO Annex 14 covers the equivalent as intermediate holding position lights: three fixed, unidirectional yellow lights, 1.5 m apart, across the taxiway centreline. Check which term and layout your regulator uses.
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