Definition
A feature in an area navigation (RNAV) or flight management system that gives the pilot a visual or aural warning shortly before the aircraft reaches a waypoint, so the next leg of the route can be anticipated and flown accurately.
Plain English
A heads-up from the navigation system that the next turn point is coming up, so you're ready to follow the new course.
Context Anchor
Seen when using an aircraft navigation unit or handheld navigator to follow a planned route.
Derivation
Waypoint comes from way (a route or path) and point (a specific location), meaning a fixed spot along the route. Alerting comes from the Italian all'erta, meaning 'on the watch.' Together, the term describes the system watching the route and warning the pilot when a key point is approaching.
Why Pilots Care
It prevents late recognition of an upcoming turn or fix, reducing the chance of course deviation or workload spikes.
Intuition Check
Waypoint alerting does not mean the aircraft has already reached the waypoint. It means the system is giving advance notice that the waypoint is near.
Example Sentence 1
About ten seconds before reaching the fix, the GPS waypoint alerting flashed on the display, and the pilot prepared to turn onto the next leg.
Example Sentence 2
As waypoint alerting activated on the moving map, the crew began their descent checklist for the arrival.