What does the touchdown zone light pattern look like?
Pairs of short white light bars either side of the centreline, starting at the threshold and running up to 900 m.
Touchdown zone lights are pairs of barrettes either side of the centreline, running up to 900 m from the threshold on precision approach CAT II and III runways (ICAO Annex 14). Pairs are spaced 30 m or 60 m apart along the runway.
Each barrette has at least three lights, not more than 1.5 m apart, and is 3 to 4.5 m long. On a runway shorter than 1,800 m the pattern is shortened so it does not extend beyond the midpoint.
One row on the centreline, about 15 m or 30 m apart. See Entry 34.
Barrette pairs either side, 30 m or 60 m apart, over the first 900 m.
Frequently Asked Questions
Q1What are touchdown zone lights?
Touchdown zone lights are rows of short white light bars (barrettes) set in the runway either side of the centreline, starting at the threshold. They help the pilot judge the touchdown zone and the distance remaining in low visibility.
Q2How far do touchdown zone lights extend?
ICAO Annex 14 Volume I extends them 900 m from the threshold. On a runway shorter than 1,800 m the pattern is shortened so that it does not extend beyond the midpoint of the runway. The FAA pattern runs 3,000 ft (about 900 m); check the edition in force.
Q3How far apart are the barrette pairs?
The pairs of barrettes are spaced longitudinally at either 30 m or 60 m, as chosen in the design. The same choice applies along the whole pattern.
Q4What is a barrette?
A barrette is a short transverse bar of closely spaced lights. For touchdown zone lights ICAO calls for at least three lights, not more than 1.5 m apart, with the barrette not less than 3 m and not more than 4.5 m long.
Q5How is the lateral spacing set?
The barrettes are in pairs, symmetrical about the runway centreline. The gap between the innermost lights of a pair matches the lateral spacing chosen for the touchdown zone marking.
Q6Where are touchdown zone lights required?
On precision approach CAT II and CAT III runways under ICAO Annex 14 Volume I (Chapter 5, touchdown zone lights). Confirm against the current edition, the FAA AC 150/5340-30 where it applies, and the project specification.
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