A Notice to Airmen (NOTAM), Also known as Notice to Air Missions (FAA definition), is a notice containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations.
(ICAO Annex 11, Air Traffic Services)
NOTAMs are issued by national authorities for a number of reasons, such as:
- Hazards such as air-shows, parachute jumps and glider or micro-light flying;
- Flights by important people such as heads of state;
- Closed runways, taxiways, etc;
- Unserviceable radio navigational aids;
- Military exercises with resulting airspace restrictions;
- Unserviceable lights on tall obstructions;
- Temporary erection of obstacles near airfields (e.g. cranes).
For reasons of conciseness and precision, NOTAMs are encoded, although the code is usually sufficiently self-evident to allow the user to identify a hazard.
NOTAMs are communicated by the issuing agency using the fastest available means to all addressees for whom the information is assessed as being of direct operational significance, and who would not otherwise have at least seven days' prior notification.
Flight Crew Access to current NOTAMS during pre flight planning may be via airport Flight Briefing Facilities provided for all aircraft operators or via an alternative 'tailored access' system provided by their Company which will provide access only to NOTAMS relevant to their intended flight.
Trigger NOTAMs serve to alert those who maintain aeronautical databases that specific changes will be effective soon, usually at the next AIRAC date. A trigger NOTAM contains a brief description of the contents of the amendment or supplement, the effective date and the reference number of the amendment or supplement. It is usually valid for 14 days.
Snow conditions are notified, not by NOTAM but by a special message called SNOWTAM. Similarly, volcanic ash is notified as a special message known as an ASHTAM.
Full details concerning the content and distribution of NOTAMs, SNOWTAMs and ASHTAMs are contained in ICAO Annex 15.
The Digital NOTAM Project
The EUROCONTROL Digital NOTAM (xNOTAM) Project, run in cooperation with US FAA, has as an objective the provision of NOTAM information in a format that would make it suitable for automatic processing. This will enable automated systems that support ATC and air navigation to have a more actual view of the aeronautical environment, thus increasing the safety and efficiency of the ATM system.