Definition
A network of evenly spaced horizontal and vertical lines superimposed on a chart, map, or display to provide a reference system for locating points, measuring distances, or organizing data.
Plain English
A pattern of crossing lines used as a reference framework. The lines create boxes, and any point can be described by which line it falls on or near.
Context Anchor
Pilots may see grids on aviation charts, airport diagrams, navigation displays, or search-and-rescue planning maps.
Derivation
From 'gridiron,' an old word for a metal cooking frame made of parallel bars. The pattern of crossing lines on a chart looks like that frame, so the same word was carried over.
Why Pilots Care
Enables reliable heading and position references in polar areas where magnetic variation is extreme and true north converges.
Analogy
A grid works like the lines on graph paper. The lines do not change the area itself; they give you a simple way to point to a place on it.
Intuition Check
Do not assume grid means an electrical power system here. In aviation chart and map use, a grid means a reference pattern of crossing lines used to locate places.
Example Sentence 1
The pilot used the latitude and longitude grid on the sectional chart to locate the reported position of the disabled aircraft.
Example Sentence 2
Plotting the return leg on the grid allowed them to maintain a constant heading without constant magnetic corrections.