aeronautical information circular (AIC)
A notice containing information that does not qualify for the origination of a NOTAM (notices to airmen) or for inclusion in the AIP (aeronautical information publication) but that relates to flight safety, air navigation, or technical, administrative, or legislative matters. AICs lapse after five years but, if still considered important, may be reissued. The AICs are color coded: white means operational circulars; yellow pertains to administrative matters, including ATC (air traffic control) facilities and requirements; pink signals safety issues; green pertains to map and chart information; and mauve intimates amendments and airspace restriction charts.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved