Definition
A flight route that is navigated by the pilot using onboard navigation equipment and ground-based navigation aids, without the aircraft being tracked or guided by ATC radar. Position is determined and reported by the pilot rather than observed on a controller's radar display.
Plain English
A route you fly using your own navigation instruments, where ATC is not watching you on radar. You tell them where you are; they don't see you on a screen.
Context Anchor
Seen in air traffic control and instrument flying discussions when a route is flown without radar-based steering from a controller.
Derivation
"Nonradar" simply means "without radar." The term exists because ATC operations are normally radar-based, so routes flown outside radar coverage need their own label and procedures.
Why Pilots Care
Requires strict adherence to published routes, mandatory position reports at designated points, and increased pilot responsibility for separation and navigation.
Intuition Check
Do not read “nonradar route” as meaning no one can see the aircraft on radar. It means the route itself is not being flown by radar vectors from air traffic control.
Example Sentence 1
Once they crossed into the nonradar route segment, the crew began making mandatory position reports at each compulsory reporting point.
Example Sentence 2
ATC issued a nonradar route through the mountainous area, requiring the pilot to maintain the published airway without radar assistance.