Definition
A compact disc produced by the U.S. National Geospatial-Intelligence Agency (NGA, formerly NIMA) that contains a comprehensive digital database of worldwide aeronautical information, including airports, navigation aids, airways, special-use airspace, waypoints, and other flight-planning data. The disc is updated on a regular cycle and is used to load or refresh the navigation databases of avionics systems, flight management systems, and flight-planning software.
Plain English
A CD that holds a worldwide collection of up-to-date flight information — runways, navigation aids, airways, and so on — used to update the data inside aircraft navigation equipment and flight-planning programs.
Context Anchor
Seen in older references to FAA or aviation data products, especially when discussing electronic flight information before most data was delivered online.
Derivation
‘Aeronautical’ comes from the Greek aēr (air) and nautikos (relating to ships or sailing) — literally ‘navigating the air.’ ‘Digital’ signals that the information is stored as computer data rather than printed charts. The term simply describes what the disc holds: air-navigation information in digital form.
Why Pilots Care
Gave pilots a portable, searchable way to carry and update large amounts of flight data without stacks of paper publications.
Intuition Check
Do not read “Cd” here as a music disc or as the chemical symbol for cadmium. In this aviation context, it means a compact disc used to carry flight-related data.
Example Sentence 1
Before the cross-country flight, the avionics technician used the latest Digital Aeronautical Information CD to update the FMS navigation database.
Example Sentence 2
Many pilots kept a backup Digital Aeronautical Information Cd in their flight bag in case the primary database failed.