Definition
An FAA Advisory Circular in the 150/5320 series, which provides guidance, standards, and recommended practices for airport pavement and drainage design, construction, and maintenance. The number 150 identifies the airport-related series, and 5320 identifies the subject area covering airport pavement and surface drainage.
Plain English
It is an FAA guidance document that tells airport designers and operators how to build and look after runway, taxiway, and apron pavement and drainage.
Context Anchor
Seen in FAA glossary entries, airport operations material, runway condition discussions, and references to airport design or maintenance guidance.
Derivation
Advisory Circular comes from the idea of a circulating notice that advises rather than commands. Unlike regulations, ACs are guidance — they describe an FAA-accepted way of meeting a standard, not the only way.
Why Pilots Care
Consistent application of these standards produces predictable, safe airport surfaces that reduce runway excursions and support reliable aircraft performance.
Intuition Check
Do not read AC 150/5320 as an aircraft equipment code. Here, AC means Advisory Circular, and the number is a reference to FAA airport guidance.
Example Sentence 1
The airport engineer referenced AC 150/5320 when specifying the new runway's pavement thickness.
Example Sentence 2
Before approving the taxiway extension, the engineer verified compliance with AC 150/5320 geometric requirements.