Definition
A path terminator leg in an RNAV procedure that instructs the aircraft to fly a specified magnetic heading until it intercepts the next leg of the procedure. The leg has no defined endpoint of its own; it terminates only when the aircraft crosses the course of the following leg.
Plain English
Fly this heading until you cross the next part of the procedure, then turn onto it.
Context Anchor
Seen in instrument procedure coding and on GPS or flight-management-system displays for departures, arrivals, and missed approaches.
Derivation
In ARINC 424 path terminator coding, each leg type is named by two letters: the first letter is the path being flown, the second is what ends the leg. 'V' stands for a heading (vector) and 'I' stands for an intercept. So 'VI' literally reads as 'heading-to-intercept.'
Why Pilots Care
Ensures the aircraft joins the intended track at the correct angle without overshooting or requiring last-minute corrections.
Intuition Check
Do not read “heading” as the exact path over the ground; wind can push the aircraft sideways while it holds that heading. “Intercept” means joining the specified course, not just crossing near it.
Example Sentence 1
After takeoff, the SID coded a VI leg of 090, so we held that heading until the FMS captured the next airway segment.
Example Sentence 2
After takeoff we flew the assigned heading to an intercept to meet the outbound course at the proper angle.