Definition
Advisory Circulars are non-regulatory documents issued by the FAA to provide guidance, information, and accepted methods for complying with regulations or for performing specific aviation activities. They are organized by subject matter using the same numbering system as the Federal Aviation Regulations (for example, AC 61-65 relates to 14 CFR Part 61).
Plain English
ACs are FAA-published booklets that explain how to do things correctly. They are not rules themselves, but they show pilots and operators an FAA-approved way to meet the rules or carry out a task.
Context Anchor
Pilots encounter Advisory Circulars when looking up FAA guidance on training, aircraft operation, maintenance, airports, airspace, and other aviation subjects.
Derivation
‘Advisory’ comes from the Latin advisare, meaning ‘to give counsel.’ ‘Circular’ refers to a document circulated to a wide audience. Together the term means a piece of guidance distributed broadly — counsel, not command.
Why Pilots Care
They help pilots understand how to apply regulations in practice and adopt safer procedures.
Intuition Check
Do not assume “advisory” means “unimportant.” An AC may not be a regulation by itself, but it often tells you the FAA’s accepted way to do something safely or correctly.
Example Sentence 1
Before her checkride, the student reviewed AC 61-65 to understand what the FAA expected from a private pilot applicant.
Example Sentence 2
Many instructors recommend reading the relevant Advisory Circulars before a checkride.