Definition
A specific ground-based navigation facility located near Grand Junction, Colorado, identified by the three-letter ident JNC. It is a VORTAC, meaning it combines a VOR (which provides bearing information) and a TACAN (which provides distance information usable as DME by civil aircraft). Pilots and procedure designers reference JNC by name when it is used as a fix, a course reference, or a navigation aid on instrument procedures in that region.
Plain English
It is the name of a particular navigation station on the ground at Grand Junction, Colorado. Aircraft tune to it to find out which direction they are from the station and how far away they are. The letters JNC are its short identifier, the way an airport has a three-letter code.
Context Anchor
Seen in instrument procedure text, charts, and path-and-terminator leg examples when a route or leg is tied to the Grand Junction navigation facility.
Derivation
Grand Junction is the city in western Colorado where the facility is located. JNC is its assigned three-letter identifier, used in flight plans, charts, and avionics. VORTAC is a combination of VOR and TACAN, two types of ground navigation equipment housed at the same site.
Why Pilots Care
If a procedure uses the Grand Junction (JNC) VORTAC as a reference, the pilot must identify the correct facility and use the proper course or distance from it. Confusing it with another fix or station could put the aircraft on the wrong path.
Grounding Statement
Picture it as a known radio landmark on the ground that aircraft instruments can use to help define where the airplane is and where it should go next.
Intuition Check
Do not read JNC as just an airport code or a random label. Here it identifies a specific ground navigation facility used by the procedure.
Example Sentence 1
After departure, we tracked outbound from the Grand Junction (JNC) VORTAC on the 270 radial until reaching 25 DME.
Example Sentence 2
After crossing the Grand Junction (JNC) VORTAC the procedure turns outbound on the next leg.