AirNav.com is a supplemental resource for pilots and aviation enthusiasts. The site publishes aeronautical and airport information released by the Federal Aviation Administration (FAA) such as runway distances, airfield traffic patterns, airport frequencies (common traffic advisory frequency (CTAF), tower, ground, Automatic Terminal Information Service (ATIS)/Automated Weather Observing System (AWOS)/Automated Surface Observing System (ASOS), instrument landing system (ILS), approach and departure, center or ARTCC, clearance delivery, emergency, and Flight Service Station (FSS)/fixed-base operator (FBO) frequencies), airport operations, facilities and services, chart location, navigational coordinates and locations, radio aids, ownership information and other pertinent information that all pilots need when traveling into or out of an airport or around the United States National Airspace System (NAS). The same information is published in the Airport/Facility Directory (A/FD), updated every 56 days.