Definition
A black square sign with a yellow letter and yellow border (e.g., 'A') placed immediately next to a runway holding position sign, indicating the name of the taxiway on which the aircraft is currently positioned at the hold-short line.
Plain English
A small sign placed right beside the red 'hold short' sign that tells you which taxiway you are sitting on while you wait. The two signs are mounted together so you can read them at a glance.
Context Anchor
Seen on airport taxiways, especially near runway holding positions where pilots must confirm both their location and the instruction shown by the sign.
Derivation
Collocated' comes from Latin 'com-' (together) and 'locare' (to place) — literally 'placed together'. In this context it simply means the location sign is mounted next to the holding position sign so the pilot reads them as a pair.
Why Pilots Care
Confirms exact surface position and helps prevent runway incursions by giving clear location information right where the decision to hold or cross is made.
Grounding Statement
Picture stopping before a runway and seeing a red holding sign with a black-and-yellow “A” sign beside it; the “A” tells you that your current taxiway is Taxiway Alpha.
Intuition Check
Do not read “collocated” as meaning the Taxiway Alpha sign replaces the other sign. It means the Taxiway Alpha location sign is mounted with it or placed at the same location.
Example Sentence 1
Holding short of Runway 27, the pilot glanced at the collocated Taxiway Alpha location sign and confirmed to ground control, 'Holding short Runway 27 on Alpha.'
Example Sentence 2
At the holding position the crew checked the collocated Taxiway Alpha location sign to verify they were on the correct taxiway.