← Back to Aviation Glossary
Advisory Circular (AC)
An FAA publication that provides non-regulatory guidance on aviation subjects such as certification, currency, and training standards. Advisory Circulars like AC 61-65 (endorsements) and AC 61-98 (flight review) explain how to meet the regulations in practice.
Want to go beyond the definition? This term is covered in depth in AviatorPro's Private Pilot License ground school.
Learn more in Private Pilot License →Related Terms
- AFM (Airplane Flight Manual)The FAA-approved flight manual for an airplane that contains operating limitations, procedures, and performance information. Under 14 CFR 91.9, pilots must comply with the AFM or approved POH limitations, and the required manuals must be available in the aircraft when the type design requires them.
- AGL (Above Ground Level)A measurement of altitude expressed in feet above the terrain or ground directly below the aircraft. AGL is commonly used for traffic pattern altitudes and obstacle clearance.
- AileronA hinged flight control surface on the trailing edge of each wing that controls the aircraft's roll about its longitudinal axis. Moving the control yoke or stick left or right deflects the ailerons in opposite directions.
- AIM (Aeronautical Information Manual)The FAA's official guide to basic flight information and ATC procedures for operating in the National Airspace System. Pilots use the AIM for practical guidance on topics such as airport lighting, weather services, and communications that complement the regulations in the FARs.