Definition
A pilot action on a GPS or flight management system that tells the unit to begin sequencing the loaded instrument approach procedure, switching navigation guidance from the en route phase to the approach segments so the system will guide the aircraft through the initial, intermediate, and final approach fixes in order.
Plain English
Pressing a button or selecting an option on the navigation system to tell it: start running the approach now. Once activated, the system stops pointing you toward the airport in general and starts guiding you step by step along the published approach.
Context Anchor
Seen on instrument-flight GPS or moving-map pages when selecting an approach to an airport, including from a nearest-airports page.
Derivation
Activate comes from the Latin actus, meaning to do or to set in motion. In this context, the pilot is setting the loaded approach into motion so the system begins using it for navigation.
Why Pilots Care
Enables rapid setup of guidance to an alternate airport without manually searching and loading the full procedure from the database.
Grounding Statement
After activation, the navigator treats the selected approach as the route it should guide you on now.
Intuition Check
Do not assume “activate the approach” means you are cleared to fly the approach. It means the navigation system is now using that approach for guidance; clearance and pilot judgment are still separate.
Example Sentence 1
After being cleared for the approach, the pilot pressed the menu key and selected Activate Approach so the GPS would sequence to the initial approach fix.
Example Sentence 2
Once the approach is activated the GPS displays the initial approach fix and begins providing course guidance.