A NOTAM, or Notice to Airman, is time‐critical aeronautical information which is of either a temporary nature or not sufficiently known in advance to permit publication on aeronautical charts or in other operational publications.
NOTAM information is that aeronautical information that could affect a pilot’s decision to make a flight. It includes such information as airport or aerodrome primary runway closures, taxiways, ramps, obstructions, communications, airspace, changes in the status of navigational aids, ILSs, radar service availability and other information essential to planned enroute, terminal or landing operations.
The primary NOTAMs of relevance are the NOTAM D, FDC NOTAM, and Pointer NOTAM.
NOTAM (D) information is disseminated for all navigational facilities that are part of the National Airspace System (NAS), all public use airports, seaplane bases, and heliports listed in the Chart Supplement. NOTAM (D) information includes such data as taxiway closures, personnel and equipment near or crossing runways, and airport lighting aids that do not affect instrument approach criteria, such as VASI. NOTAM(D) includes (U) NOTAMs and (O) NOTAMs. (U) NOTAMs are unverified NOTAMs which are those that are received from a source other than airport management and have not yet been confirmed by management personnel. This is allowed only at those airports where airport management has authorized it by Letter of Agreement. (O) NOTAMs are other aeronautical information which does not meet NOTAM criteria but may be beneficial to aircraft operations.
FDC NOTAMS or Flight Data Center NOTAMS are NOTAMs that are regulatory in nature such as changes to an instrument approach procedure and other current aeronautical charts Temporary Flight Restrictions (TFRs) are also issued as FDC NOTAMs.
Pointer NOTAM are issued by a flight service station to highlight or point out another NOTAM, such as an FDC or NOTAM (D). A pointer NOTAM will assist users in cross-referencing important information that may not be found under an airport or NAVAID identifier. Keywords in pointer NOTAMs must match the keywords in the NOTAM that is being pointed out. The keyword in pointer NOTAMs related to Temporary Flight Restrictions (TFR) must be AIRSPACE.
NOTAM (L) is now used only in the military NOTAM system. All NOTAMs previously considered NOTAM (L)s in the civil NOTAM system are now considered NOTAM (D)s. A NOTAM L is given local dissemination by voice and other means, such as telautograph and telephone, to satisfy local user requirements.
NOTAMS are published in the Notice to Airmen Publication every 4 weeks. Once published, the information is not necessarily provided during pilot weather briefings unless specifically requested by the pilot.
NOTAM data may not always be current due to the changeable nature of national airspace system components, delays inherent in processing information, and occasional temporary outages of the U.S. NOTAM system. While enroute, pilots should contact Flight Service Station (FSS)s and obtain updated information for their route of flight and destination.
AIM 2018 5-1-1. Preflight Preparation
AIM 2018 5-1-3. Notice to Airmen (NOTAM) System