Definition
A computed vertical descent path defined by the flight management system (FMS) that connects altitude constraints along an instrument procedure, providing a continuous, stabilized descent profile typically at a fixed flight path angle (commonly around 3 degrees). The aircraft follows this path using vertical guidance from the FMS, either advisory or coupled to the autopilot, depending on equipment and procedure type.
Plain English
A descent slope calculated by the aircraft's computer that the pilot follows down from cruise to the runway, hitting the required altitudes along the way smoothly instead of stepping down in chunks.
Context Anchor
Seen during instrument procedure planning, descent planning, and when using panel guidance that shows whether the airplane is above or below the planned vertical course.
Derivation
VNAV stands for Vertical Navigation. 'Path' here means the actual three-dimensional descent track the aircraft flies — not just a target altitude, but a continuous slope through the sky.
Why Pilots Care
Keeps the aircraft on a safe descent profile that meets all altitude restrictions and allows arrival at the runway at the correct height.
Analogy
Think of it like a ramp drawn in the sky. The airplane is not just going toward a point on the map; it is also trying to arrive there at the planned height.
Grounding Statement
Picture the system drawing a sloping line from your present altitude to the altitude you need at a later point.
Intuition Check
Do not treat a VNAV path as automatic permission to descend. It is guidance; the pilot still needs the correct clearance and must confirm the airplane remains at safe and required altitudes.
Example Sentence 1
After crossing the initial fix, the crew armed VNAV and let the autopilot capture the VNAV path down to the next altitude restriction.
Example Sentence 2
Before descent the crew checked that the VNAV path satisfied every crossing altitude on the arrival.