Definition
The planned or unplanned removal from service of a VOR or VORTAC ground navigation station, which makes any airway, route, instrument approach, or procedure that depends on that station temporarily unusable and triggers the need for a substitute route or alternate means of navigation.
Plain English
A ground-based navigation station has been turned off or is out of service. Any route or approach that relies on it cannot be flown until ATC issues a replacement route or another way to navigate is approved.
Context Anchor
Seen in instrument procedure and airway discussions when older ground-based navigation routes are being replaced, revised, or supported by substitute route structures.
Derivation
"Shutdown" is a plain English term meaning to stop operating. Applied here to a specific ground station (VOR or VORTAC), it simply means that station is no longer transmitting a usable signal.
Why Pilots Care
It changes the planned route and may require GPS or another navaid to maintain legal and safe navigation.
Grounding Statement
Picture a route that once pointed pilots from one ground station to the next; if one station is removed, the route has to be rebuilt or replaced so pilots still have a usable path.
Intuition Check
Do not assume shutdown only means a brief power-off event. In this context, it means the facility is unavailable for navigation use, often as part of a planned change to the route system.
Example Sentence 1
Because of the VOR/VORTAC shutdown at the en route facility, ATC issued a substitute route using GPS waypoints to keep the flight on its filed airway structure.
Example Sentence 2
Before departure we confirmed no VOR/VORTAC shutdown affected our airway.