A NOTAM (Notice to Air Missions) is an official notice filed with aviation authorities to alert pilots and flight crews about conditions that could affect flight safety or planning.
How It Works#
NOTAMs are issued by aeronautical authorities, airports, and air navigation service providers. They cover temporary changes to airspace, navigation aids, runways, lighting, and procedures. Each NOTAM has a defined effective time, so pilots know exactly when the condition starts and ends.
The FAA manages NOTAMs in the United States through the Flight Service and the NOTAM Distribution System. ICAO sets the international standards for NOTAM format and distribution under Annex 15 to the Convention on International Civil Aviation. Most countries follow this standard, which means a pilot flying internationally can read any NOTAM with a familiar structure.
NOTAMs use a coded format with specific fields. These fields include the NOTAM number, the affected location (using an ICAO identifier), the subject, the condition, and the validity period. The format is dense but consistent, so pilots learn to read it quickly with practice.
There are several NOTAM types. The most common include:
- NOTAM D — distributed widely and stored in databases for preflight planning
- FDC NOTAM (Flight Data Center) — used in the U.S. for regulatory changes, such as temporary flight restrictions (TFRs)
- International NOTAMs — distributed through ICAO's NOTAM network for cross-border operations
- Trigger NOTAMs — issued to alert pilots that a new aeronautical chart or publication is taking effect
Example in Aviation#
A pilot planning a cross-country flight to a regional airport checks NOTAMs during preflight planning. She finds a NOTAM stating that the instrument landing system (ILS) on Runway 28L is out of service for maintenance until a specific date and time. She adjusts her approach planning accordingly and files for an alternate instrument approach.
Without checking NOTAMs, she might have planned an approach that was unavailable, creating a serious problem during a low-visibility arrival.
Why It Matters#
Checking NOTAMs before every flight is a regulatory requirement under 14 CFR §91.103. That regulation requires pilots to familiarize themselves with all available information for a flight, and NOTAMs are a core part of that picture. Skipping NOTAM review has contributed to real accidents and incidents.
Beyond compliance, NOTAMs carry information that no other preflight source provides. A runway closure, a drone operation area, a military exercise, or a VIP movement can appear in a NOTAM and nowhere else. Treating NOTAM review as a checkbox rather than a genuine information-gathering step is a mistake.
Key Takeaways#
- A NOTAM alerts pilots to temporary or urgent changes affecting flight safety.
- Pilots must review NOTAMs before every flight under 14 CFR §91.103.
- NOTAMs cover airspace, navaids, runways, procedures, and temporary restrictions.
- FDC NOTAMs carry regulatory force, including temporary flight restrictions.
- ICAO Annex 15 sets the international standard for NOTAM format and distribution.