How to Read NOTAMs Without Missing the One That Matters

Half of the active domestic NOTAMs in the United States say the same thing: a tower light is out. The one closing your destination runway from 1100Z to 1900Z looks exactly like them. 14 CFR 91.103 requires the pilot in command to become familiar with all available information concerning the flight before it begins, and AIM 5-1-3 says this includes NOTAMs. Nothing in either document says you must read them in the order the system hands them to you.

The format is learnable in an evening.

What a NOTAM is, and what it is not

A NOTAM is a notice containing information essential to flight operations that was not known far enough in advance to be publicized by other means, and it states the abnormal status of a component of the National Airspace System, never the normal status (FAA NOTAM overview page).

Two habits of the system follow from AIM 5-1-3 a. A NOTAM may be disseminated up to 7 days before the activity starts, so a closure you read on Monday may not begin until the weekend. It is cancelled when the condition returns to normal or when the information is published on a chart. The FAA's public tool is NOTAM Search.

If you call for a standard briefing, the specialist is required to advise you of pertinent NOTAMs, and the AIM tells you to remind them if they skip it (AIM 5-1-1 c). A self-briefer gets no such backstop.

The anatomy of a domestic NOTAM, field by field

Domestic NOTAMs are assembled in a fixed order: accountability location, NOTAM number, affected location, keyword, the condition, and last the start of activity and end of validity, always in UTC (FAA pilot NOTAM primer, 2021). Here is a composed example in the standard format. It is an illustration, not a real notice.

!RDU 10/042 RDU RWY 05L/23R CLSD 2610071100-2610071900

• RDU, with the leading exclamation point, is the accountability location, the NOTAM file that logs the notice. The Chart Supplement lists it for each airport and NAVAID under "NOTAM FILE", and it is not always the facility affected.
• 10/042 is the number: a two-digit month, then a three-digit serial that restarts at 001 each month for that accountability. The number carries the month and not the year, so a list sorted by number is not in date order.
• RDU after the number is the affected location.
• RWY is the keyword. For RWY, TWY and APRON a surface designator must follow it, here 05L/23R.
• CLSD is the condition.
• 2610071100-2610071900 is the period, two 10-digit groups in YYMMDDHHMM: 1100 UTC to 1900 UTC on October 7, 2026. FAA Order JO 7930.2U, chapter 3 section 3 fixes the 10-digit UTC format and runs the day from 0000 to 2359.

Two endings deserve a second look. The suffix EST after the end time means the end is an estimate, and the AIM's own COM example notes that an EST NOTAM auto-cancels (AIM 5-1-3, NOTAM Keywords table, COM row). PERM in place of an end time means the content is headed for the Chart Supplement or another publication, and the NOTAM stands in until it gets there (FAA primer, FAQ A5).

A schedule, when there is one, sits just before the start time: MON-FRI SR-SS, DLY SR-1800, TUE 2300-SR, where SR and SS are sunrise and sunset (7930.2U, chapter 3 section 3). The same section makes a hyphen between days mean "through" and a space mean "only those days". MON-FRI is five days. MON WED FRI is three.

The keyword tells you the subject before you read the condition

Every NOTAM D must carry one keyword from a fixed list as the first part of the text after the location identifier, and the keywords exist so you can sort by subject, because the system itself does not prioritize anything (AIM 5-1-3 g.1; FAA NMS FAQs). The FAA primer dates the keywords to 2008 and says the same thing in fewer words: NOTAMs are displayed first come, first served.

The keywords and example text below come from the NOTAM Keywords table in AIM 5-1-3; the examples are the AIM's, shortened. Search the page by the table's name: the body text numbers it TBL 5-1-1 and the caption says TBL 5-1-3.

The last three rows are the regulatory keywords you will see on FDC NOTAMs. Everything above them is NOTAM D territory. In FlyFren's snapshot of the live FAA feed on October 3, 2026, OBST opened 13,220 of the 22,731 active domestic NOTAM Ds, which is why a raw list reads like a tower-light inventory (What 69,000 active NOTAMs actually say).

Contractions you will meet in nearly every list

NOTAM text uses contractions designated for ICAO use, and where no contraction exists, plain language is required (7930.2U, chapter 3 section 3). Two decoding rules from the same section save a lot of head-scratching: a contraction written in the singular also means the plural, and one written in the past tense also means the present. CLSD covers "close, closed and closing".

The AIM publishes a table of contractions commonly found in NOTAMs (AIM 5-1-3, Contractions Commonly Found in NOTAMs). The ones below are drawn from it.

A few phrases are standardized rather than contracted. The order's table of standard NOTAM phrases includes WI AN AREA DEFINED AS, CENTERED AT, BTN and AND, NOT LGTD, FLAGGED, NOW for a temporary change and CHANGED TO for a permanent one. In taxiway NOTAMs a cardinal direction is spelled out in full, EAST or SOUTHWEST, so TWY E means Echo, not east.

NOTAM D, FDC, TFR and international formats

The AIM sorts NOTAMs into four classifications, and a single briefing can contain all of them (AIM 5-1-3 g).

A NOTAM D covers NAS navigation facilities, all public-use airports, seaplane bases and heliports in the Chart Supplement, and it is the keyword-first format decoded above. Taxiway closures, people and equipment near runways, and lighting that does not affect instrument approach minimums all live here. So do pointer NOTAMs, which point at another notice, often a TFR, and must carry the same keyword as the original.

An FDC NOTAM is regulatory. It carries amendments to instrument approach procedures and charts, Temporary Flight Restrictions, high barometric pressure warnings, laser activity, ADS-B and FIS-B availability, and WAAS or GPS status. Its number looks different too: a single year digit, a slash and a four-digit serial such as 6/1234. The primer warns that serials are recycled, so the highest number is not the newest. A TFR is therefore an FDC NOTAM, not a separate species, and the AIM points you at online resources that draw it on a map with a plain-language summary. The FAA's own is tfr.faa.gov.

International NOTAMs follow ICAO Annex 15 and read differently. A Q line a computer can parse comes first, then lettered fields: A is the location, B the start and C the end in year-month-day-hour-minute, D a schedule when present, E the full text, F and G the lower and upper limits when present. Stripped to those fields, the runway closure from above would look like this (composed, simplified):

A) KRDU B) 2610071100 C) 2610071900
E) RWY 05L/23R CLSD

Military NOTAMs use the international format and matter at joint-use fields; the primer's advice is to read both the civil and the military notices there.

One more file you must open: the ARTCC. AIM 5-1-3 c says to review NOTAMs for the center whose airspace you will cross, for example ZDC for Washington Center, because CARF, special use airspace, TFRs, GPS, route changes and UAS activity are filed there and not under your airports. Security notices live under KZZZ and KICZ.

How do you triage 60 NOTAMs in five minutes?

Sort by keyword, read every RWY, AD and IAP line for the airports you will use, then the AIRSPACE and NAV lines along the route, and only then skim OBST (AIM 5-1-3 b). That paragraph lists what NOTAMs can affect; the routine below is that list in the order it can hurt you.

1. Surfaces at departure, destination and alternate: RWY, AD, TWY, APRON. If the runway you need is CLSD inside your window, nothing else matters yet. Note partial closures given in feet from an end and displaced thresholds, because they change your landing distance math under 91.103(b).
2. Times. Filter to your window. A DLY 0400-1000 schedule may never touch a noon arrival. NOTAM times are UTC; Eastern Standard Time is UTC minus 5 hours and Pacific Standard Time minus 8 (AIM 4-2-12), one hour less during daylight time.
3. FDC for the procedures you will fly. IAP, ODP, SID and STAR amendments change minimums and missed approach instructions. A VFR pilot can usually skip these. An IFR pilot cannot.
4. The center file. Open the ARTCC identifier for TFRs, GPS testing, UAS and special use airspace along the route.
5. NAV, 25 nm either side of the whole route. That is the FAA primer's best practice, because a NAVAID may serve several airports and appear under none of them, and its NOTAM file can differ from the airport's. A VOR U/S matters on a GPS-direct flight if it is your backup.
6. AIRSPACE and OBST, in that order. Parachute, UAS and aerobatic activity first. Then obstacles: at night or in low visibility, tower lights U/S near your route and pattern; by day, cranes near the approach path, which give height and distance from the field.

Then keep going en route. AIM 5-1-3 d tells pilots to contact ATC or FSS before arrival for a destination update, especially at non-towered airports, because snow removal, construction and wildlife may not have been known before departure. If you are on flight following, the controller is already on frequency to ask.

The GPS and parachute NOTAMs people skip

GPS NOTAMs use three terms, and the AIM defines them: UNRELIABLE (UNREL), MAY NOT BE AVAILABLE (AVBL) and NOT AVAILABLE (AIM 5-1-3 f). UNREL means the expected level of GPS or WAAS service may not be there, the pilot must judge whether the signal is adequate, and the aircraft should have other navigation equipment for the route. Testing NOTAMs carry the name of the test in parentheses. When testing is under way, ATC will tell a pilot cleared for a GPS or RNAV (GPS) approach that GPS may not be available and ask for intentions.

They are filed under the GPS and center accountabilities, not under your airport, so the AIM says to search for them specifically. Read the footprint carefully. The AIM's example testing NOTAM covers a 276 nm radius at FL400 and down to a 126 nm radius at 50 ft AGL: the affected area shrinks as you descend, so a NOTAM that looks like half the country may or may not include a trainer at 3,500 ft. Work out which ring you are in first.

Parachute jumping carries the AIRSPACE keyword and the contraction PJE, as in the primer's example AIRSPACE PJE WI AN AREA DEFINED AS 5NM RADIUS OF APT SFC-15000FT. UAS activity is written the same way, under AIRSPACE and not AD. Both disappear from a list filtered to airport NOTAMs only. The drop zone next to the field you are landing at is in the airspace file, not the airport file.

What is changing: NMS and the ICAO format

As of October 3, 2026, the FAA has finished the first phase of replacing its NOTAM system and has not yet set a date for changing the format pilots read. The new NOTAM Management Service (NMS) began operating on September 29, 2025 (FAA NOTAM overview page, updated September 30, 2025). On May 12, 2026 the FAA announced phase one complete: the legacy US NOTAM System was shut down and its users moved to NMS in mid-April 2026, and the remaining legacy Federal NOTAM System is to be retired "later this year", after which NMS becomes the single authoritative source (FAA newsroom, May 12, 2026).

The keyword format survives for now. The FAA's NMS FAQ, last updated August 25, 2026, says the agency will adopt the ICAO NOTAM format and replace the domestic one, but will set that schedule only after the NMS transition is complete, and that NMS does not change NOTAM policy in Order 7930.2 (FAA NMS FAQs). The current edition of that order is JO 7930.2U, basic dated June 9, 2025, with Change 1 of August 10, 2025 and Change 2 of September 30, 2026.

When the switch comes, the A) B) C) E) layout above is what the domestic line will turn into.

Where FlyFren fits into this

FlyFren's airport pages show the current NOTAMs for a field next to its METAR and TAF, pulled from the FAA's NMS data feed. Treat that as supplemental planning information. The FAA system is the source of truth, and NOTAM Search or your briefing is what 91.103 asks you to be familiar with. On October 3, 2026 the live feed held 69,011 active notices. A routine gets you to the ones that touch your flight.

This article is educational and is not a substitute for the current regulations, the AIM, official weather briefings, or instruction from a CFI. Check the current text at the linked sources before you rely on any detail.