Definition
An indication shown on a GPS or flight management display confirming that a particular mode or function (most commonly the approach mode) has been selected and is now ready to activate automatically when the appropriate conditions are met. The system is staged but not yet engaged.
Plain English
A message on the screen telling the pilot that a function is set up and waiting, and will switch on by itself at the right moment.
Context Anchor
Seen on a GPS navigator or flight display while loading, activating, or flying a GPS instrument approach.
Derivation
From the verb 'to arm,' meaning to prepare a device so it will act when triggered — the same sense as arming an alarm or a switch. 'Annunciation' comes from the Latin annuntiare, meaning 'to announce.' Together: the system is announcing that it is prepared and ready to act.
Why Pilots Care
Confirms the navigation system is correctly configured so the pilot can anticipate when guidance will become active and avoid missing the approach capture.
Intuition Check
Do not read “armed” as “already working.” Armed means ready to activate; active means it is working now.
Example Sentence 1
About 30 miles from the destination, the pilot saw the approach arm annunciation appear on the GPS, confirming the approach was loaded and ready to activate.
Example Sentence 2
Once the arm annunciation appeared, the system was ready to capture the approach course.