Definition
Lights placed along the perimeter of an airport landing area to mark its outer limits, particularly at airports without paved runway edge lighting. They define where the usable landing surface ends.
Plain English
Lights around the edges of the landing area that show pilots where the airport ends and the surrounding ground begins.
Context Anchor
Seen in airport lighting descriptions and during night operations at airports or landing areas.
Derivation
Boundary comes from the Old French 'bodne,' meaning a limit or marker. Here it keeps that original sense: lights marking the outer edge of the usable landing area.
Why Pilots Care
Helps pilots confirm the usable landing surface and avoid landing short, long, or on unprepared ground at night.
Intuition Check
Do not assume boundary lights are the same as runway edge lights. Boundary lights mark the outside limits of an airport or landing area; runway edge lights mark the sides of a runway.
Example Sentence 1
Approaching the grass strip after sunset, the pilot used the boundary lights to identify the usable landing area.
Example Sentence 2
Boundary lights outlined the grass strip so the night landing could be completed safely.