Cause & Circumstance: Why You Need To Understand NOTAMs

Runway 06L at Montreal/St.-Hubert Airport four days after the Global Express incident.
Credit: Transportation Safety Board of Canada

This is a follow-on article to 'A (Bad) Landing Surprise'

Canada’s Transportation Safety Board (TSB) does not publish CVR transcripts, so we don’t have a word-for-word record of what exactly was said by the pilots of the Bombardier Global Express involved in the landing incident at Montreal/Saint-Hubert Airport on May 15, 2017. The TSB also does not provide probable cause statements of the kind issued by the NTSB, but it does provide findings. In its analysis, the TSB addressed crew situational awareness, flight planning, approach and landing preparation, marking of runways under construction, and conciseness and clarity of notices to airmen (NOTAMs).

The TSB said that despite the information provided to the crew about half of the runway being closed, “this information does not seem to have been compelling to or absorbed by the flight crew, and they adopted a mental model that was resistant to change and to the apprehension of elements that are critical to a safe landing.” The TSB was unable to determine why the crew read but not did grasp the meaning of the NOTAMs, why the FO did not understand or share the critical ATIS information about the runway with the captain, or why the crew did not recognize the temporary runway markings.

Regarding NOTAMs, the TSB only said they are complex to decipher and that sometimes crews may simply skim or forget them. They recommend the words “reduced width” should be incorporated in NOTAMs when appropriate. They also noted that neither the crew nor the company provided the 48 hr. prior notice to DASH-L that was required by NOTAM for airplanes with a wingspan in excess of 78 ft.

Questions I have that went unanswered include supervisory and organizational factors. Was there someone at Zetta Air who had flight planning responsibility and should have been aware of the long-standing restrictions to operations at CYHU? Was the crew notified in sufficient time before the trip to be able to assess the airport safety factors before they launched? Would the captain have been criticized if he decided to divert to the more suitable Trudeau Airport? Did the management at Zetta Air spend more time finding the right caviar for customers than planning safe flights?

The facts presented by the TSB report clearly show the errors made by the crew. The crew had enough information to avoid the incident, and just didn’t heed it. They were careless. Having said that, I think there is more to the story.

The Problem With NOTAMs

If the incident crew or anyone at Zetta Air had actually read the NOTAMs, they would have realized they weren’t in compliance with the 48-hr. prior notice requirement. They would have requested special permission to land or made the flight to another airport. The flight started off on the wrong foot. An obvious reason is because NOTAMs are such a chore to read.

Bloated, jargon-filled NOTAMs have been the accepted international standard since before Charles Lindbergh. According to, the 5-bit ITA2 upper-case code used for NOTAMs was begun in 1924 and has remained essentially unchanged. Despite recurring complaints from pilots and reputable organizations, the system has only gotten worse. According to OpsGroup, a flight planning and information sharing organization, the states that generate the NOTAMs prioritize legal self-defense over usability by pilots. Thus unnecessary notices drown out meaningful information.

The problem surfaced during the 2018 NTSB meeting for the Air Canada Flight 759 incident, a near-catastrophic low pass over a taxiway full of idling jetliners. The crew had missed a NOTAM about a runway closure, and that triggered the incident. Then-NTSB Chairman Robert Sumwalt said NOTAMs were “just a bunch of garbage” and “the system was really messed up.” The Safety Board issued recommendation A-18-24, which said “Establish a group of human factors experts to review existing methods for presenting flight operations information to pilots, including flight releases and general aviation flight-planning services (preflight) and aircraft communication addressing and reporting system messages and other inflight information; create and publish guidance on best practices to organize, prioritize and present this information in a manner that optimizes pilot review and retention of relevant information; and work with air carriers and service providers to implement solutions that are aligned with the guidance.”

In response, the FAA said in 2020 that they had established a committee to look into the problem.

One positive development has been the collaboration of OpsGroup with the International Civil Aviation Organization (ICAO) to address the NOTAM problem. They’ve created an artificial intelligence “bot” called “Norm” to evaluate all of the NOTAMs issued around the world. On a typical day, there are 35,000 NOTAMs in effect, and Norm scores them all for length, timeframe, format and other criteria to come up with a NOTAM quality score. There’s a “NOTAMeter” on the ICAO website that you can access to see how different regions and countries rate. Produced in bright colors, it looks like a large beach ball on the deck of the grey battleship that is the ICAO website. Go to

As this is written, the NOTAMeter says only 12.41% of worldwide NOTAMs meet all quality criteria. The Russian Federation has 30.72% of its NOTAMs meeting the quality criteria, and China manages 18.43%. In North America, you will find 4.24% meet the criteria, with the U.S. bringing up the rear at just 3.42%. The U.S. wins the prize for worst NOTAM in the region, a truly incomprehensible mélange pertaining to flight planning (I think).

If you have the time and an internet connection, you can go to the FAA’s NOTAM search website and pull up the NOTAMs for your destination airport. You can select individual NOTAMS, and in some cases even get a plain-language translation. Just pulling up CYHU today, I find 15 NOTAMs. They are still dense (TWY B BTN ENA AND 240FT FR ENA CLSD) and lack plain-language versions.

If you are on a short callout for a trip to a major airport, you will have a problem sorting out the real hazards from the dross in the destination NOTAMs. For example, today Chicago O’Hare Airport (KORD) has 89 NOTAMs. You can spend 20 min. reading them and still not be sure you understand everything. That is not a good situation. Let’s hope the FAA will start to realize that excessive and unreadable NOTAMs are a real safety issue.