NOTAM

A Notice to Airmen (NOTAM) is a notice filed with an aviation authority to alert aircraft pilots of potential hazards along a flight route or at a location that could affect the safety of the flight. NOTAMs are unclassified notices or advisories distributed by means of telecommunication that contain information concerning the establishment, conditions or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel and systems concerned with flight operations. NOTAMs are created and transmitted by government agencies and airport operators under guidelines specified by Annex 15: Aeronautical Information Services of the Convention on International Civil Aviation (CICA). The term NOTAM came into common use rather than the more formal Notice to Airmen following the ratification of the CICA, which came into effect on 4 April 1947. Notices to Airmen were normally published in a regular publication by each country's air authorities (e.g., in Flight Magazine in the UK). A number of developments and amendments to the CICA have resulted in the more automated system available today.

A NOTAM is filed with an aviation authority to alert aircraft pilots of any hazards en route or at a specific location. The authority in turn provides a means of disseminating relevant NOTAMs to pilots.

NOTAMs are issued (and reported) for a number of reasons, such as:

Aviation authorities typically exchange NOTAMs over AFTN circuits.

Software is available to allow pilots to identify NOTAMs near their intended route or at the intended destination.

In the U.S. Air Force information technology enterprise, C4 NOTAMs (Command, Control, Communications, and Computer Notices to Airmen) are notices of new or updated Air Force Network Operating Instructions (AFNOIs). Often, these notices serve to direct Air Force computer administrators to install security updates or change the configuration of computer systems.

The following describes ICAO NOTAMs. NOTAMs are published using all upper case letters which are claimed by some to make NOTAMs difficult to read. Note that some countries such as the United States may diverge from the following ICAO standards.

This is a typical NOTAM for London Heathrow airport:

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