QCodes are now available in API! ... and why we don't like them

We're announcing that QCodes are now available in the Notamify API - in responses, filtering, and the Watcher API. Full documentation is available at notamify.com/api-docs.

While this was a frequently requested feature, we want to be transparent about why we have reservations about relying on them.

What Are QCodes?

QCodes (or Q-groups) are five-letter codes embedded in the Q-line of NOTAMs. They were originally designed to help air operations teams quickly identify critical NOTAMs without reading the full free-text description.

The structure encodes:

• 2nd/3rd letters: Subject being affected (runway, lighting, navigation aid, etc.)
• 4th/5th letters: Condition or status (closed, unserviceable, limited, etc.)

There are approximately 200 predefined QCode combinations, detailed in ICAO Doc 8400 and regional supplements like FAA Order JO 7930.2. The intent was standardization, a common language for NOTAM categorization worldwide.

The Problems with QCodes

1. Frequently Inaccurate

QCodes are often assigned incorrectly or don't reflect the actual content of the NOTAM. The code might indicate one subject while the free-text describes something entirely different.

Real example from EPWA (Warsaw):

Q) EPWW/QMXLT/IV/M/A/000/999/5210N02058E005
E) TWY D5 CLSD.

The QCode QMXLT means "taxiway limited" - but the NOTAM text clearly states TWY D5 CLSD (closed). The correct code (in our understanding) should be QMXLC. If you're filtering for closed taxiways using QCodes, this NOTAM would be missed entirely.

2. Not Enough Codes

The predefined set of ~200 QCodes cannot cover every operational scenario. When NOTAM issuers encounter a situation without a matching code, they default to generic QCodes.

Real example from CYVR (Vancouver):

Q) CZVR/QFAXX/IV/NBO/A/000/999/4912N12311W005
E) RSC 08L 5/5/5 100 PCT WET, 100 PCT WET, 100 PCT WET. CHEMICALLY TREATED...

The QCode QFAXX is "aerodrome, other" - a catch-all because no specific code exists for runway surface condition reports. This NOTAM contains critical runway condition data for four runways, but the generic QCode tells you nothing about it.

3. Regional Inconsistency

Despite ICAO standards, QCode usage varies significantly across the globe. Different countries, ANSPs, and airport authorities interpret and apply QCodes differently. A NOTAM from Europe and one from Asia covering identical situations may carry different QCodes.

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Why We Added Them Anyway

Our customers asked for QCode support - for filtering workflows, legacy system integrations, and compliance with existing procedures. We've enabled:

• QCode fields in API responses
• QCode filtering parameters for queries
• QCode-based triggers in the Watcher API for alerts

You can now filter NOTAMs by QCode patterns (e.g., all QMR* codes for runway-related notices) or include them in automated monitoring rules.

Our Recommendation: Use Atomic Elements Instead

Given the limitations above, we strongly recommend using Atomic Elements as your primary source of NOTAM intelligence rather than QCodes.

Atomic Elements provides:

Atomic Elements answers the questions you actually need answered:

• Which runways are closed?
• What taxiways are restricted?
• Which approaches are unavailable?
• What lighting systems are affected?

These answers come from analyzing the whole NOTAM content.

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Summary

• QCodes are now available in the Notamify API, including Watcher API
• They were designed for quick identification but suffer from regional inconsistency, limited coverage, and frequent inaccuracies
• We've enabled them to meet customer needs, but recommend Atomic Elements for reliable NOTAM intelligence
• Documentation: notamify.com/api-docs

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QCodes represent aviation's attempt at standardization from decades past. Atomic Elements is our answer to what modern NOTAM intelligence should look like.