Definition
Flight Service Stations are FAA air traffic facilities that provide a range of services to pilots, primarily before and during flight, but excluding active air traffic control separation services. Their core functions include providing preflight weather briefings, accepting and processing flight plans, relaying air traffic control clearances, issuing Notices to Air Missions (NOTAMs), broadcasting aviation weather and information, providing en route flight advisory service, assisting lost or disoriented aircraft, and notifying search and rescue when an aircraft is overdue.
Plain English
FSS is an FAA service that helps pilots with weather, flight plans, and information before and during a flight. They don't control traffic, but they support the pilot with everything else needed for safe flying.
Context Anchor
Pilots encounter FSS when getting a preflight weather briefing, filing or opening a flight plan, asking for updates by radio while airborne, or closing a flight plan after landing.
Derivation
The name is descriptive: a 'station' (a fixed facility) that provides 'service' to 'flights.' Worth noting because the word 'station' here means a service center, not a stopping point along a route.
Why Pilots Care
They supply up-to-date weather and route data that directly affects go/no-go decisions and in-flight safety.
Intuition Check
Do not picture FSS as an air traffic control tower giving takeoff and landing instructions. FSS is mainly an information and flight-plan support service for pilots.
Example Sentence 1
Before departure, the pilot called Flight Service to file an IFR flight plan and get a standard weather briefing.
Example Sentence 2
While en route the pilot radioed an FSS specialist to activate the filed flight plan.