Definition
A Computer Navigational Fix (CNF) is a charted point defined by latitude and longitude that exists primarily for use by an aircraft's flight management system or area navigation (RNAV) computer. A CNF is identified on charts by a five-letter name in parentheses (for example, (CHEKK)) and is depicted with a small filled circle marker. CNFs are not intended to be used by pilots for clearances, ATC instructions, position reporting, or filing flight plans, and are not assigned by ATC.
Plain English
A point on a chart that exists mainly for the airplane's navigation computer to use as a reference. Pilots see it on the chart, but they don't read it back to ATC, get cleared to it, or use it like a normal waypoint.
Context Anchor
Seen on FAA instrument chart legends and en route low altitude charts, especially where charted points support computer-based navigation.
Derivation
The name describes its function: it is a fix (a defined navigational point) that exists for the navigation computer rather than for the pilot or controller. The parentheses around its five-letter name on the chart are a visual cue that it is a 'computer-only' identifier.
Why Pilots Care
Pilots need to recognize CNF symbols to understand the full set of available navigation points when planning or flying IFR routes that rely on GPS.
Intuition Check
Do not read “fix” as “repair.” In this term, a fix is a known location. Also, a CNF is not just any GPS point; it is a specific database point used to support navigation and charting.
Example Sentence 1
Looking at the en route chart, the pilot noticed (CHEKK) was a CNF and ignored it for flight planning, since ATC would not issue a clearance to it.
Example Sentence 2
When reviewing the en route chart legend, the pilot noted the CNF symbol to confirm it could be used for GPS navigation.