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Free Guide · Regulations & Procedures

Understanding NOTAMs

11 chapters · glossary

A NOTAM (Notice to Air Missions) exists because a chart, no matter how recently printed, is already out of date the moment something changes: a runway closes for repaving, a light goes out, a temporary restriction pops up. NOTAMs are how that gap between "what the chart says" and "what's actually true right now" gets closed, and reviewing them properly is a required, not optional, part of flight planning.

In this guide

  1. What a NOTAM Actually Is
  2. NOTAM Categories
  3. The Coded Format
  4. Decoding a Sample NOTAM
  5. FDC NOTAMs
  6. Temporary Flight Restrictions (TFRs)
  7. Where to Actually Find NOTAMs
  8. An Efficient Review Workflow
  9. Worked Example
  10. Common Mistakes and Practical Tips
  11. Glossary

1. What a NOTAM Actually Is

A NOTAM is a short, time-critical notice about a change to the aeronautical system, anything from a runway closure to an inoperative navaid to newly established special use airspace, that isn't yet reflected on published charts and won't be until the next publication cycle. Checking NOTAMs before a flight is a required part of preflight planning under 14 CFR 91.103, alongside weather and performance data.

Key Idea A NOTAM is temporary, time-sensitive information. If it were permanent and stable, it would already be on the chart; the fact that it's a NOTAM at all means it's either new, short-lived, or urgent enough not to wait for the next chart cycle.

2. NOTAM Categories

CategoryCovers
NOTAM (D) / DistantAirport and navaid specific info: runway/taxiway closures, lighting, obstructions
FDC NOTAMRegulatory changes: TFRs, amended instrument procedures, chart corrections
Military NOTAMMilitary airport and MOA/range activity, distributed separately from civil NOTAMs
Pointer NOTAMDraws attention to another NOTAM (often an FDC or TFR) affecting a wider area

3. The Coded Format

A standard NOTAM follows a fixed structure: a NOTAM number (a letter and four digits, e.g. A0123/26), the affected location's identifier, the subject and condition using standard abbreviations, and effective start and end times in Zulu (UTC), formatted as year-month-day-hour-minute. Abbreviations are dense but standardized: "RWY" for runway, "CLSD" for closed, "TWY" for taxiway, "OBST" for obstruction, "U/S" for unserviceable.

4. Decoding a Sample NOTAM

!KABC 08/015 KABC RWY 09/27 CLSD 2609081200-2609091800

At Springfield (KABC), runway 09/27 is closed, effective the 8th of September (2026) at 1200Z through the 9th at 1800Z. Reading a NOTAM is mechanical once the abbreviation set is familiar: location, subject, condition, then the time window, in that order, every time.

Practical Tip Keep a short reference list of the most common NOTAM abbreviations handy until they become second nature; the format itself never changes, only the specific abbreviations used in any given notice.

5. FDC NOTAMs

FDC (Flight Data Center) NOTAMs carry regulatory weight: they amend instrument approach procedures, publish new Temporary Flight Restrictions, and correct chart errors. Because they can directly change a procedure's legality or minimums, they deserve particular attention when planning an IFR flight or a flight anywhere near an area with active TFR activity (major sporting events, VIP movements, wildfires, disaster response).

6. Temporary Flight Restrictions (TFRs)

A TFR defines airspace where flight is restricted, sometimes to all aircraft and sometimes only to aircraft without specific authorization, for a defined period and reason: presidential movements, major sporting events, disaster or firefighting response, or space launch operations. TFRs are published as FDC NOTAMs and can appear or change with very little notice, which is exactly why checking NOTAMs close to the actual flight time, not days in advance, matters.

Common Trap Checking NOTAMs during initial trip planning and never rechecking closer to departure is a common oversight; TFRs in particular can be published or modified within hours of a flight.

7. Where to Actually Find NOTAMs

NOTAMs are available through official sources (a standard weather briefing, the FAA's NOTAM search tool) and through most electronic flight bag apps, which typically organize them more usefully by route and airport than a raw text dump. Whatever the source, the underlying data and coded format is the same; the presentation is just more or less convenient to review.

8. An Efficient Review Workflow

Rather than reading every NOTAM along a route with equal attention, a practical approach is to triage: scan departure and destination airport NOTAMs first (since they affect the parts of the flight with the least margin for surprise), then check for any TFRs along the route, then review enroute navaid or airway NOTAMs relevant to the specific navigation method being used.

9. Worked Example

Planning a flight from KABC to KXYZ, the departure airport NOTAM shows a taxiway closure requiring an alternate taxi route, the destination shows the ILS glideslope out of service (meaning only localizer minimums are available if flying that approach), and a route-wide TFR search reveals a new sporting-event TFR partially overlapping the planned route, requiring a reroute around its lateral boundaries. None of this appears on any chart, all of it comes from the NOTAM review.

10. Common Mistakes and Practical Tips

MistakeTreating NOTAM review as optional or skippable "if the weather looks fine." NOTAMs cover far more than weather, including closures and restrictions with real legal and safety consequences.
MistakeChecking NOTAMs once, early in planning, and not rechecking close to departure when TFRs or new restrictions could have been published since.
MistakeSkimming past dense abbreviated text rather than actually decoding it, missing an operationally significant closure or restriction.
Practical TipUse an electronic flight bag's NOTAM organization features (grouped by category, highlighted TFRs) rather than a raw, unsorted text feed whenever available.
Practical TipRecheck NOTAMs as close to actual departure time as practical, especially for anything TFR-related.

Glossary

NOTAM
Notice to Air Missions — a time-critical notice about a change not yet reflected on published charts.
NOTAM (D)
A NOTAM covering airport or navaid-specific information, such as runway or taxiway closures.
FDC NOTAM
A NOTAM carrying regulatory weight, including TFRs and amended instrument procedures.
TFR
Temporary Flight Restriction — airspace where flight is restricted for a defined period and reason.
U/S
Unserviceable — standard NOTAM abbreviation for equipment that is out of service.

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This guide is intended for educational and training purposes only. It is not a substitute for official FAA publications, an authorized ground school, or qualified flight instruction, and should not be used as a sole source for real-world flight planning, dispatch, or operational decisions.