Plain English Meaning

It's the letter at the end of an approach name that tells you which version of that approach you're flying. If an airport has more than one approach of the same type to the same runway, each one gets its own letter so pilots and controllers know exactly which chart to use.

Full Definition

A single letter (A, B, C, etc.) added to the end of an instrument approach procedure title to distinguish between two or more approaches of the same type to the same runway, or to identify approaches that do not provide straight-in landing minimums to a specific runway. Suffixes begin with the letter A and continue alphabetically. When a procedure terminates in circling-only minimums (no straight-in runway alignment), the suffix is paired with a runway-independent identifier such as the airport name or a directional reference.