How to read a NOTAM
NOTAMs are written to be transmitted cheaply, not to be read comfortably. Once you know what each field is doing, a wall of capitals turns into four or five facts. Here is a real-shaped NOTAM taken apart line by line.
The full NOTAM
A1234/26 NOTAMN Q) EGTT/QMRLC/IV/NBO/A/000/999/5128N00027W005 A) EGLL B) 2609010600 C) 2609011800 D) DLY 0600-1800 E) RWY 09L/27R CLSD DUE WIP. TWY B CLSD BTN TWY A AND TWY C. ILS RWY 27R U/S.
The header first: A1234/26 is the series letter, number and year. NOTAMN means new — NOTAMR replaces an earlier one, NOTAMC cancels one.
Field by field
Qualifier line
EGTT/QMRLC/IV/NBO/A/000/999/5128N00027W005
The machine-readable summary. EGTT is the FIR. QMRLC is the Q-code: MR = runway, LC = closed. IV means it affects IFR and VFR traffic. NBO covers the purpose — immediate attention, briefing bulletins, operationally significant. A is the scope (aerodrome). 000/999 are the vertical limits in flight levels. The last group is the centre point and a 5 NM radius.
Location
EGLL
The ICAO location indicator this applies to — an aerodrome, or an FIR for en-route notices. More than one can be listed.
Valid from
2609010600
Start of validity as YYMMDDHHMM in UTC: 1 September 2026 at 06:00Z.
Valid until
2609011800
End of validity, same format. PERM means it is permanent and heading for the AIP. EST after the time means estimated — expect it to be replaced or cancelled.
Schedule
DLY 0600-1800
When the condition is actually active inside the B)-C) window. This is the field pilots skip and then get caught by. Outside these hours the NOTAM does not apply to you.
The text
RWY 09L/27R CLSD DUE WIP. TWY B CLSD BTN TWY A AND TWY C. ILS RWY 27R U/S.
The narrative, written in ICAO contractions: runway 09L/27R closed due to work in progress; taxiway B closed between taxiway A and taxiway C; the ILS for runway 27R is unserviceable.
Height limits
SFC / FL200
Lower and upper limits, used mainly for en-route and navigation-warning NOTAMs such as drone activity, balloon ascents or restricted areas.
Three traps worth knowing
- Valid is not active. The most common error is treating a NOTAM that is valid today as one that affects your flight. Check the D) schedule against your actual off-blocks time, plus taxi. A closure running 2100-0300Z has nothing to do with a 17:30Z push.
- Everything is UTC. Every time in a NOTAM is Zulu. Local summer time has caught out more crews than any Q-code ever has.
- The important line is rarely the first one. A frequency change, a lighting change or a displaced threshold is often buried halfway down a pack of forty notices that are mostly cranes and unserviceable windsocks. Volume, not complexity, is what makes NOTAMs dangerous.
Decode one now, free
Paste any NOTAM into our free decoder and read it in plain English — or let Dispatch Brief take your whole route pack and give you back only what matters, in your own language.
Frequently asked
What does NOTAM stand for?
Notice to Air Missions (formerly Notice to Airmen). It is a short, standardised notice telling pilots about a change to the aviation system that they could not reasonably have known about — a closed runway, an unserviceable navaid, a crane, a drone display, restricted airspace.
What is the difference between B), C) and D) on a NOTAM?
B) is when the NOTAM starts being valid and C) is when it stops. D) is the schedule inside that period during which the condition is actually active. A NOTAM can be valid for a month under B) and C) while D) means it only applies 2100-0300Z each night — so it may not affect a mid-afternoon departure at all.
What does U/S mean on a NOTAM?
Unserviceable. The facility named — an ILS, a PAPI, a runway lighting system — is out of service and must not be relied on.
What is a Q-code on a NOTAM?
The five-letter code in the Q) line, always starting with Q. Letters two and three name the subject (MR is runway, IC is ILS, NV is VOR). Letters four and five name its condition (LC is closed, AS is unserviceable, HW is work in progress). So QMRLC means runway closed.
Do I still have to read NOTAMs if I use a decoder?
Yes. A decoder makes the text readable, but you remain responsible for checking the official source for your flight and deciding what it means for your operation.
Keep reading
Free NOTAM decoder
Paste a raw NOTAM and read it in plain English.
Free METAR & TAF decoder
Decode aviation weather reports and forecasts, group by group.
NOTAM abbreviations list
Searchable reference of every common contraction.
What is a NOTAM?
The basics: what they are, why they exist, and the different types.
For training and situational awareness only. Always cross-check with your official briefing source before flight.