Quadrant Identifier

Quadrant Identifier is a system used to quickly pinpoint specific areas on sectional charts, dividing each 30-minute latitude/longitude cell into four 15-minute quadrants, identified by numbers (1–4) or letters (A–D), and used for quick reference and communication.

Purpose

Quadrant identifiers serve as a shorthand for pilots to describe specific areas to air traffic control, weather services, or other pilots.

Structure

• A 30-minute latitude/longitude cell is the basic unit, and each cell is divided into four 15-minute quadrants.
• Northwest Quadrant = 1 or A
• Northeast Quadrant = 2 or B
• Southwest Quadrant = 3 or C
• Southeast Quadrant = 4 or D

Example

A location might be described as "O06AG3" where the first five characters are the 30-minute cell designation, and the sixth character is the quadrant number.

Further Subdivision

Each 15-minute quadrant can be further divided into nine 5-minute by 5-minute areas, resembling a telephone keypad, and identified by a seven-character designation.

Application

• Sectional Charts: Quadrant identifiers are prominently displayed on sectional charts.
• Communication: Pilots use quadrant identifiers to quickly and accurately describe their location or the location of an event during radio communications.
• Maximum Elevation Figure (MEF): One of the most important features found within each quadrant is the Maximum Elevation Figure (MEF), a number found in each quadrant of the sectional chart.