What Are NOTAMs and Why They Matter
A Notice to Air Missions (NOTAM) is a notice containing information essential to personnel concerned with flight operations. NOTAMs alert pilots to temporary or permanent changes to airports, airspace, navigation aids, and procedures that are not yet reflected in published charts or supplements.
NOTAMs are legally binding. Under 14 CFR 91.103, pilots are required to become familiar with all available information concerning a flight before departure. This explicitly includes NOTAMs. A pilot who misses a relevant NOTAM has no regulatory defense.
The term changed from "Notice to Airmen" to "Notice to Air Missions" in 2021, though the acronym and function remain the same.
ICAO NOTAM Format (Post-2022)
In January 2022, the FAA adopted the ICAO NOTAM format, replacing the legacy domestic format. The new format is more structured and internationally standardized. A typical ICAO NOTAM has these components:
Q line (qualifier): Contains the FIR (Flight Information Region), NOTAM code, traffic type, purpose, scope, lower/upper limits, and geographic coordinates. This enables automated filtering. Example: Q) ZNY/QMRLC/IV/NBO/A/000/999/4038N07346W005
A line (location): The ICAO identifier of the affected location (e.g., A) KJFK).
B line (start time): When the NOTAM becomes effective, in UTC (e.g., B) 2604160800).
C line (end time):When the NOTAM expires (e.g., C) 2604162000). "PERM" indicates a permanent change.
D line (schedule): If the NOTAM is active only during specific hours (e.g., D) DAILY 0800-2000).
E line (body text):The human-readable description of the NOTAM's content (e.g., E) RWY 04L/22R CLSD).
The ICAO format is more verbose but dramatically easier for software to parse, which improves EFB (electronic flight bag) filtering and alerting.
Types of NOTAMs
D NOTAMs (distant/local): The most common type. These cover airport-specific information: runway closures, taxiway restrictions, lighting outages, navaid outages, and obstacle changes. D NOTAMs are attached to a specific airport identifier.
FDC NOTAMs (Flight Data Center):Issued by the FAA's Flight Data Center in Washington, DC. These cover regulatory changes, airspace amendments, chart corrections, instrument procedure changes, and GPS RAIM outages. FDC NOTAMs often affect instrument approaches — a common example is an ILS approach with revised minimums due to an obstacle.
TFR NOTAMs (Temporary Flight Restrictions): Issued under 14 CFR 91.137, 91.138, 91.141, or 91.143 to restrict flight in specific areas. Common triggers: presidential movement (the most common), disaster relief, major sporting events, space launches, and firefighting operations. TFRs define precise coordinates, altitudes, and effective times.
Pointer NOTAMs: Alert pilots to look at NOTAMs for a nearby or related facility. For example, a pointer NOTAM at KJFK might direct you to check NOTAMs for the New York TRACON or a nearby airport with relevant airspace changes.
Military NOTAMs: Cover military airfields, ranges, and operations. Distributed through military channels and may also appear on FAA NOTAM Search for areas that affect civilian operations.
How to Read a NOTAM
Start with the E line — this is the human-readable summary. Most of what you need to know is there. Then check the B and C lines for the effective period. If you are flying outside that window, the NOTAM does not affect you.
Key abbreviations you will see repeatedly: RWY (runway), TWY (taxiway), CLSD (closed), AP/AD (airport/aerodrome), APCH (approach), LGT/LGTD (light/lighted), ODP (obstacle departure procedure), SVC (service), U/S (unserviceable), WIP (work in progress), ABN (aerodrome beacon), PAPI (precision approach path indicator), VASI (visual approach slope indicator), and REIL (runway end identifier lights).
Time is always in UTC (Zulu). All altitudes are MSL unless otherwise noted. Coordinates use degrees and minutes (DDMM format in the Q line).
A practical reading approach: for each NOTAM, ask three questions. First, does it affect my route, departure, or destination? Second, is it active during my flight time? Third, does it require me to change my plan (alternate runway, modified approach, different altitude)?
Where to Find NOTAMs
FAA NOTAM Search (notams.faa.gov): The official FAA source. You can search by airport, route, location, or ARTCC area. This replaced the legacy PilotWeb system. It supports filtering by NOTAM type, keyword, and date range.
FSS briefing (1-800-WX-BRIEF): Calling Flight Service provides a pilot briefing that includes relevant NOTAMs along your route. The briefer will highlight TFRs, runway closures, and other critical items. This also creates a legal record that you received a briefing.
Electronic Flight Bags (EFBs): Modern EFB apps integrate NOTAM data and overlay TFRs on maps. They can filter and highlight NOTAMs by relevance, making the briefing process much faster than reading raw text.
DATIS/ATIS: Automated weather broadcasts at towered airports include current pertinent NOTAMs affecting the airport. Listen on approach to get the latest information.
Best practice: use a single integrated EFB that ingests the FAA NOTAM Management System feed directly. AeroCopilot polls the FAA NMS every 15 minutes, classifies each NOTAM, and pairs it with a graphical TFR overlay so pilots see one consolidated preflight picture instead of stitching two disparate sources.
Effective NOTAM Briefing Strategies
The biggest challenge with NOTAMs is volume. A busy airport like KJFK can have 50-100 active NOTAMs at any time, and most are irrelevant to a specific flight. Effective briefing means triaging ruthlessly.
Priority 1 — Safety critical: TFRs along your route or near your airports. Runway closures at your departure, destination, and alternate. Navaid outages affecting your planned approaches. Airspace restrictions.
Priority 2 — Operationally significant: Taxiway closures (affect ground movement), lighting outages (night operations), PAPI/VASI outages (visual approach aids), and construction activity on or near runways.
Priority 3 — Nice to know: Crane operations nearby (noted for obstacle awareness), wildlife advisories, parachute operations in the area, and scheduled events that may increase traffic density.
What you can usually skip: NOTAMs about services you will not use (e.g., military frequencies at a civil airport), facilities at airports far from your route, and permanent NOTAMs that are already reflected in your current chart edition.
A final tip: re-check NOTAMs immediately before departure. New TFRs or runway closures can be issued with short notice. A NOTAM that did not exist during your morning briefing may be active by your afternoon departure.