What Is a NOTAM and How Do Pilots Read One?

A NOTAM (Notice to Air Missions) is a time-critical notice that tells pilots about temporary or unplanned changes to the National Airspace System—things like closed runways, unserviceable navaids, or restricted airspace. Pilots are legally required to review NOTAMs relevant to their route before flight, and reading one means decoding a fixed format of contractions, effective times, and location identifiers. This guide explains what NOTAMs carry, how to parse a raw line, and how to prioritize them so you don't miss the one that matters.

What Information a NOTAM Carries

NOTAMs exist because the information they contain is too urgent or too short-lived for charts and publications, which update on slower cycles. Common content includes:

• Runway and taxiway conditions — closures, surface contamination, or lighting outages
• Navaid and communication outages — a VOR, ILS, or frequency out of service
• Airspace restrictions — temporary flight restrictions (TFRs), parachute jumps, airshows
• Obstacles and hazards — cranes, unlit towers, laser activity
• Airport services — fuel unavailable, customs hours changed, arresting gear status

If it changes between chart cycles and affects safety or legality, it likely appears as a NOTAM.

Why NOTAMs Are Legally Required

Under FAA rules, pilots must become familiar with all available information concerning a flight before departing—and NOTAMs are part of that "all available information" package alongside weather and performance data. Ignoring a relevant NOTAM can mean:

• Legal exposure — operating contrary to a published restriction
• Safety risk — landing on a closed runway, flying into active restricted airspace, or losing a navaid you planned to use
• Operational surprises — arriving to find no fuel, no customs, or a closed primary runway

The obligation is not to read every NOTAM in the system, but to review those that apply to your departure, destination, alternate, and route.

Breaking Down the Standard NOTAM Format

A raw NOTAM line follows a fixed order. Here's a representative example:

!JFK 06/045 JFK RWY 04L/22R CLSD 2606011200-2606011800

That time string reads: year 26, month 06, day 01, 1200Z through 1800Z. Misreading it is one of the most common errors—see the pitfalls section below.

Common Abbreviations to Know

• CLSD — closed
• U/S or UNSVC — unserviceable / out of service
• AVBL — available
• WEF — with effect from
• TIL — until
• EST — estimated
• PERM — permanent
• TFR — temporary flight restriction
• OBST — obstacle
• APCH — approach

How to Prioritize NOTAMs for Your Flight

A raw dump for a busy airport can run dozens of lines. Reading top to bottom wastes attention. Filter in this order:

1. Departure, destination, and alternate airports — start here
2. Your route and any navaids you'll use — especially approach aids
3. Airspace along the route — TFRs and restrictions
4. Time relevance — discard anything whose effective window doesn't overlap your flight
5. Category — runway closures and airspace restrictions outrank cosmetic or service notes

Tools like Notamify are built around this problem: the site describes transforming "complex NOTAM data into precise, human-friendly summaries tailored to your flights," which is the summarization step that replaces manual scanning of a raw list.

Common Pitfalls and How to Verify Currency

• Misread effective times — NOTAM times are in UTC (Zulu). A NOTAM that looks expired in local time may still be active, or vice versa. Always convert.
• Stale NOTAMs — a NOTAM may be superseded or cancelled by a later one. Check for the most recent sequence number on the same subject.
• Scope confusion — a NOTAM filed under a region may not apply to your specific airport. Confirm the location identifier matches your field.
• Skipping the alternate — pilots often brief the destination thoroughly and neglect the alternate, where a closure can matter most.
• Assuming a briefing is current — NOTAMs can be issued minutes before departure. Re-check close to your departure time rather than relying on a briefing pulled hours earlier.

The Bottom Line

A NOTAM is a short, standardized, time-bound notice of a change that affects your flight, and reading one means parsing its location, subject, condition, and effective window in UTC. You're required to review the ones relevant to your route, and the skill is filtering—by airport, route, time, and category—rather than reading everything. Verify currency close to departure, watch the time conversions, and don't neglect your alternate.