AAC—Aircraft Administration Communications

AAUP—Attention All Users Page

AC—Advisory Circular

ACARS—Aircraft Communications Addressing and Reporting System

ADCs—Air Data Computer

ADDS—Aviation Digital Data Services

ADF—Automatic Direction Finder

ADS—Automatic Dependent Surveillance

ADS-B—Automatic Dependent Surveillance-Broadcast

AEG—Aircraft Evaluation Group

A/FD—Airport/Facility Directory section of the Chart Supplement (CS)

AFM—Aircraft Flight Manual

AFMS—Aircraft Flight Manual Supplements

AFS—Aircraft Flight Safety

AFS—Flight Standards Service

AFSS—Automated Flight Service Station

AGL—Above Ground Level

AIM—Aeronautical Information Manual

AIP—Aeronautical Information Publication