How to Read a NOTAM: Step-by-Step Guide
Last updated: April 2026
A NOTAM (Notice to Air Missions) is a formal notice published by aviation authorities to alert pilots and flight crews about changes or hazards along a flight route or at an airport. NOTAMs follow a standardized ICAO format that can look cryptic at first glance. This guide breaks down each component so you can read any NOTAM and understand what it means for your flight.
Find the NOTAM source
Access NOTAMs through official sources. The ICAO NOTAM portal provides global coverage. The FAA NOTAM Search (notams.aim.faa.gov) covers US airspace and is publicly accessible. For other regions, check the national Aeronautical Information Service (AIS) of the relevant country. These databases organize NOTAMs by FIR (Flight Information Region) or airport ICAO code.
Identify the Q-code
The Q-line is the structured header of every NOTAM. It contains a code that describes the subject and condition. The first two letters after the Q indicate the subject (e.g., FA = aerodrome facilities, RO = runway operations, NR = RNAV route), and the next two indicate the condition (e.g., CL = closed, AS = unserviceable, AH = changed). The Q-line also specifies the affected FIR, traffic type (I = IFR, V = VFR), and scope (A = aerodrome, E = en-route).
Read the A/B/C/D/E fields
Each NOTAM has labeled fields. A) identifies the affected location using its ICAO code (e.g., EGLL = London Heathrow). B) is the start date and time in UTC. C) is the end date/time, or EST (estimated) if uncertain. D) contains schedule details if the NOTAM is intermittent rather than continuous. E) is the free-text description explaining the event in plain (abbreviated) language.
Check the validity period
The B and C fields define when the NOTAM is in effect. All times use UTC, indicated by the letter Z (e.g., 2604150800 means April 15, 2026 at 08:00 UTC). A NOTAM marked PERM has no scheduled end date. One marked EST has an estimated end that may be extended by a replacement NOTAM. Always verify that the NOTAM is still active for your travel dates.
Understand common abbreviations
NOTAMs use standardized ICAO abbreviations to save space. Common ones include: RWY (runway), TWY (taxiway), AD (aerodrome), CLSD (closed), PSN (position), OPN (open), OBST (obstacle), SVC (service), ABV/BLW (above/below), FIR (flight information region), TFR (temporary flight restriction), and U/S (unserviceable). The full list is published in ICAO Doc 8400.
Assess relevance to your route
Filter NOTAMs by the airports and FIRs along your route. Prioritize NOTAMs about airspace closures, navigation aid outages (ILS, VOR), runway closures at your departure and destination airports, and any temporary restricted areas along your flight path. For passenger awareness, the most important NOTAMs are those affecting airspace access and airport operations during your travel window.
This guide is for informational purposes only. NOTAM interpretation for operational flight planning requires professional training. Always consult official sources for authoritative information.