Definition
SSALS and SALS are two closely related approach lighting systems installed at the runway threshold to help pilots transition visually from instrument flight to landing. Both consist of a centerline of steady white lights extending outward from the runway threshold, with a single crossbar of lights forming a horizontal reference. SSALS extends approximately 1,400 feet from the threshold; SALS extends approximately 1,500 feet. They are typically installed at runways served by non-precision instrument approaches.
Plain English
These are two similar runway approach lighting systems — a line of white lights leading up to the runway with one horizontal bar across them — that help a pilot see and line up with the runway when breaking out of clouds at the end of an instrument approach.
Context Anchor
Seen on instrument approach charts and in discussions of airport lighting used during the final part of an instrument approach.
Derivation
Both names describe what the system is: a 'short' approach lighting system, meaning shorter in length than the longer high-intensity systems used for precision approaches. 'Simplified' in SSALS reflects a reduced-complexity version of the basic short system.
Why Pilots Care
Gives pilots a clear visual reference to confirm runway alignment and threshold location during reduced-visibility approaches.
Intuition Check
Do not read “simplified” as meaning the approach is easier or less demanding. Here it describes the lighting layout, not the flying task.
Example Sentence 1
The approach chart shows the runway is equipped with SSALS, so the pilot expects a centerline of white lights and a single crossbar when breaking out of the clouds.
Example Sentence 2
SSALS/SALS provides a shorter lighting array than a full approach lighting system for airports with limited space.