Definition
A designated point on a taxiway, marked by a specific surface marking and sign, where an aircraft must stop when instructed by ATC to protect the integrity of the Instrument Landing System (ILS) signal serving an active runway. Holding short of this position prevents an aircraft or vehicle from interfering with the ILS critical area, which can distort the localizer or glideslope signals being used by an aircraft on approach.
Plain English
A spot on the taxiway where you must stop when told to, so your aircraft does not disturb the radio signals an arriving aircraft is using to land in poor weather.
Context Anchor
Seen on airport surface markings, signs, and airport diagrams, especially near runways served by an instrument landing system.
Derivation
The name describes its function directly: a 'hold position' (a place to stop) protecting the 'instrument landing system' (the radio-based approach aid). It is named for what it protects, not what it looks like.
Why Pilots Care
Crossing this position can distort ILS signals and create unsafe approach conditions for arriving aircraft.
Intuition Check
“Hold position” does not mean any convenient place to wait. Here it means the exact painted or signed stop point that protects the instrument landing system signal.
Example Sentence 1
Tower instructed us to hold short of the ILS hold position on taxiway Bravo while the inbound traffic flew the Category II approach.
Example Sentence 2
During the ILS approach in progress, ground control directed the departing aircraft to remain behind the instrument landing system hold position.