Definition
A ground-based navigation aid (such as a VOR, NDB, or DME) that is owned, operated, and maintained by a government agency — typically the FAA — and is available for use by any pilot, with its signal flight-checked and published on official aeronautical charts.
Plain English
A navigation station on the ground that the government runs and keeps in good working order, free for any pilot to use and shown on the regular charts.
Context Anchor
Seen in instrument procedure and off-airway route discussions, where routes may be built using navigation aids available to all properly equipped pilots.
Derivation
‘Public’ here means owned and operated for general use by the public — as opposed to ‘private,’ which would mean owned by a company, airport, or individual. The distinction matters because IFR routes are normally built only on facilities the government has certified and monitors.
Why Pilots Care
Only public facilities are approved for use in instrument approach procedures and off-airway routing; private facilities cannot be used for IFR navigation.
Intuition Check
Do not read “public” as meaning a building or place open to visitors. Here it means the navigation aid is approved and available for general pilot use.
Example Sentence 1
When planning an off-airway route, the pilot made sure each waypoint was defined by a public navigation facility shown on the en route chart.
Example Sentence 2
Off-airway segments often depend on public navigation facilities to define fixes and courses.