Definition
The two components of a flight path that an autopilot or flight director follows. The lateral path is the horizontal track the aircraft flies over the ground (left/right steering, headings, courses, turns). The vertical path is the altitude profile the aircraft flies through (climbs, descents, altitude holds, glidepath tracking).
Plain English
Where the aircraft goes side-to-side across the ground, and how it goes up and down. Together they fully describe the flight path the autopilot is flying.
Context Anchor
Seen in instrument procedure and automatic flight system discussions, especially when an aircraft is being guided along a route or approach.
Derivation
Lateral comes from the Latin lateralis, meaning 'of the side.' Vertical comes from the Latin verticalis, meaning 'overhead' or 'upright.' So lateral path = the sideways (left/right) track, and vertical path = the up/down profile.
Why Pilots Care
These paths allow the autopilot to keep the aircraft precisely aligned for a safe landing when visibility is low.
Analogy
Think of driving with a map and a hill profile. The map shows the left-right route, while the hill profile shows how high or low the road goes along the way.
Intuition Check
Do not think of “lateral” as any sideways motion of the airplane; here it means the intended route left or right over the ground. Do not think of “vertical” as simply pointing the nose up or down; here it means the height profile the airplane is meant to follow.
Example Sentence 1
On an ILS approach, the localizer provides the lateral path and the glideslope provides the vertical path.
Example Sentence 2
During the RNAV arrival the system kept the aircraft on the programmed lateral and vertical paths all the way to the runway.