Definition
Navigation information that directs an aircraft along a desired lateral course over the ground, telling the pilot whether they are left of, right of, or on the intended track.
Plain English
Side-to-side guidance that keeps the airplane on the correct path across the ground, separate from how high or low it is.
Context Anchor
Seen in instrument navigation and RNAV discussions, especially when a display gives left-right course information to help the pilot stay on the selected route.
Derivation
Horizontal here refers to the flat plane of the Earth's surface as seen on a chart. Guidance comes from the Latin guidare, meaning to lead or direct. Together: information that leads the aircraft along its planned ground track.
Why Pilots Care
It keeps the aircraft on the planned lateral track, avoiding course deviations that could lead to airspace violations or missed approaches.
Grounding Statement
If the airplane is drifting left or right of the selected path, horizontal guidance is the information that helps the pilot see and correct it.
Intuition Check
Horizontal guidance does not mean general advice about navigation. It specifically means left-right guidance along the ground path, not height or descent guidance.
Example Sentence 1
The RNAV system provided horizontal guidance along the planned route from the departure airport to the initial approach fix.
Example Sentence 2
The pilot used horizontal guidance from the VOR to stay on the airway centerline between waypoints.