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.
The following describes ICAO NOTAMs, which may be different to US Domestic NOTAMs. Additionally, NOTAMs are poorly controlled and not all NOTAMs are issued using the required standards:
The first line contains NOTAM identification (series, sequence number and year of issue), the type of operation (NEW, REPLACE, CANCEL), as well as a reference to a previously-issued NOTAM, if applicable.
The 'Q' line holds (basic-remove) information about who the NOTAM affects along with a basic NOTAM description. This line can be encoded/decoded from tables defined by ICAO.
The 'A' line is the ICAO code of the affected aerodrome or FIR for the NOTAM. The area of influence of the NOTAM can be several hundreds of kilometres away from the originating aerodrome.
The 'B' line contains the start time and date, the 'C' line the finish time and date of the NOTAM. The date is in a USA date format of YY/MM/DD and the times are given in Universal Co-ordinated Time; also known as GMT or Zulu time.
Sometimes a 'D' line may be present. This gives a miscellaneous diurnal time for the NOTAM if the hours of effect are less than 24 hours a day. E.g. parachute dropping exercises tend to occur for short periods of a few hours during the day, but may be repeated over many days.
The 'E' line is the full NOTAM description. It is in English but heavily abbreviated. These abbreviations can be encoded/decoded by tables defined by ICAO.
When present, 'F' and 'G' lines detail the height restrictions of the NOTAM. Typically SFC means surface height or ground level and UNL is unlimited height. Other heights are given in feet or flight level or a combination of the two.
A1234/06 NOTAMR A1212/06 Q)EGTT/QMXLC/IV/NBO/A/000/999/5129N00028W005 A)EGLL B)0609050500 C)0704300500 E)DUE WIP TWY B SOUTH CLSD BTN 'F' AND 'R'. TWY 'R' CLSD BTN 'A' AND 'B' AND DIVERTED VIA NEW GREEN CL AND BLUE EDGE LGT. ADZ CTN
This decodes into the following:
SERIES and NUMBER : A1234 issued in 2006
NATURE OF THE NOTAM : Replacing NOTAM 1212 issued in 2006
FIR: EGTT (LONDON FIR)
SUBJECT: Taxiway (MX)
CONDITION: Closed (LC)
PURPOSE: NOTAM selected for immediate attention of aircraft operators (N)
PURPOSE: NOTAM selected for PIB entry (B)
PURPOSE: NOTAM Concerning Flight operations (O)
GEOGRAPHICAL LOCATION : 51°29' N 000° 28' W
OPERATIONAL RADIUS OF THE NOTAM : 5 NM
AERODROME : London Heathrow (EGLL)
FROM: 05:00 UTC 05 September 2006
UNTIL:05:00 UTC 30 April 2007
CATEGORY: Aerodromes, Air Routes and Ground Aids
DESCRIPTION: DUE WORK IN PROGRESS TAXIWAY B SOUTH CLOSED BETWEEN 'F' AND 'R'. TAXIWAY 'R' CLOSED BETWEEN 'A' AND 'B' AND DIVERTED VIA NEW GREEN CENTRE LINE AND BLUE EDGE LIGHT(ING). ADVISE CAUTION
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