Definition
A navigation fix located near the coastline that marks the transition point between the domestic route structure and the oceanic route structure. It is the handoff point where an aircraft is considered to be leaving (or entering) controlled domestic airspace and beginning (or ending) an oceanic crossing.
Plain English
A specific waypoint near the coast that acts as a gate between flying over land and flying over the ocean. Crossing it changes how the flight is controlled and tracked.
Context Anchor
Seen in flight plans, route clearances, and oceanic flight procedures when an aircraft is entering or leaving oceanic airspace.
Derivation
Coastal' comes from Latin 'costa' meaning side or rib, later 'shoreline.' 'Fix' in aviation refers to a defined geographic position used for navigation. Together: a defined position at the shoreline -- the natural boundary where domestic and oceanic procedures change.
Why Pilots Care
Provides a standardized point for position reporting and flight plan filing during domestic-to-oceanic transitions, ensuring accurate ATC coordination and separation.
Intuition Check
Do not read “fix” as something being repaired. Here, a fix is a named position on the route, and “coastal” tells you that position is near the coast.
Example Sentence 1
After crossing the Coastal FIX, the crew switched to oceanic position reporting procedures.
Example Sentence 2
The flight plan listed the coastal fix as the boundary between the domestic airway and the North Atlantic track.