On a rare occasion, Democrats and Republicans found common ground on an issue. That issue, something pilots in the U.S. have agreed upon for years, is that the current notam (notice to air missions) system stinks.
In late May, Congress gave final approval for the Notam Improvement Act of 2023.
Bipartisan support pushed the act to the finish line, one of the few standalone bills to make it through both chambers.
The tipping point for this bill to pass was the “notam outage” or service interruption that took place on Jan. 10, 2023. A technical glitch and sloppy work by a government contractor shut down flights in the U.S. for just under two hours, affecting thousands of travelers. This was the first time since Sept. 11, 2001, that flights in the U.S. were grounded on such a broad scale. The cause this time was the introduction of corrupt software into a 30-year-old computer system, not international terrorism.
With the bill’s passage, the FAA is now required to establish a task force to recommend improvements to the notam system. The bill also sets a deadline—Sept. 30, 2024—to complete the implementation of a modernized federal notam system and have a backup plan in place to avoid outages of this safety-critical system.
Another important element of the Notam Improvement Act is a requirement for the new FAA notam system to offer machine-readable and filterable information in the format used by International Civil Aviation Organization (ICAO).
Not surprisingly, the bill drew broad industry support. “Notams provide real-time information about airports and airspace to help ensure a flight is conducted safely. However, several flaws in the current system were revealed in January, when the FAA issued a nationwide ground stop in the NAS following a widespread system outage,” NBAA president and CEO Ed Bolen said. “This legislation is an important opportunity to address and remedy current notam limitations through careful application of the latest technologies.”
He continued, “We must ensure that notams are not only readily available to pilots but that the system is also resilient and relevant, with prioritization of the most critical safety information focused on operational requirements.”
FAA Responds To Notam Outage
The Notam Improvement Act addresses two major issues: an obsolete computer system that supports critical flight safety information affecting the NAS and formatting, readability, and useability issues that have been a thorn in the side of every end-user of the system for decades.
According to the FAA, “A notam is a notice containing information essential to personnel concerned with flight operations but not known far enough in advance to be publicized by other means. It states the abnormal status of a component of the National Airspace System (NAS)—not the normal status.”
Following the outage, on Feb.15, 2023, acting FAA Administrator Billy Nolen briefed the U.S. Senate Committee on Commerce, Science, and Transportation on NAS modernization efforts, the future of notams, and the FAA response to the service interruption.
Nolen provided details on the notam system saying, “The FAA’s overall notam system consists of two systems—an older U.S. notam system (legacy system) and a newer Federal Notam System. The older portion of the notam system relies on 30-year-old software and architecture.” He continued, “The Federal Notam System portion is newer and serves as part of the foundation for the FAA’s ongoing notam modernization effort.”
He then described the architecture of the legacy system and the incident where a contractor unintentionally deleted files while working to correct synchronization between the primary and backup databases. Those three backup databases are physically located in Oklahoma City (two) and Atlantic City (one).
In the early morning hours of Jan. 11, 2023, the system was restored, but formatting issues remained. After consulting with airline and safety experts, Nolen said he “ordered the ground stop to maintain safety and to preserve predictability.” Once resiliency testing was completed, he lifted the ground stop.
Preliminary findings of the service interruption point to an error by a contractor. There was no evidence of a cyberattack or any other malicious attempt. According to Nolen, “We have implemented new protocol that [now] requires more than one individual to be present and engaged in oversight when work on the database occurs.”
Why Notams Stink
Mark Zee, founder of the OpsGroup flight information service said, “Your job as a pilot at briefing time, is to find the one notam that will end your career or endanger your aircraft, in a package the same size as a short novel.” Somewhere, after reading about faded taxiway lines or non-standard markings, buried deep in the briefing packet, is information about a runway closure or an unusable approach.
Unfortunately, this played into the July 2017 incident involving the flight crew of Air Canada Flight 759. After a long nighttime flight, from Toronto to San Francisco, the Airbus A320 pilots overlooked a notam that Runway 28L was closed. When cleared for a visual approach to Runway 28R, they instead lined up on a taxiway that was parallel to the runway.
On this taxiway, there were four airliners awaiting takeoff—two Boeing 787s, an Airbus A340, and a Boeing 737. Combined, including the Air Canada A320, there were over 1,000 passengers on these aircraft.
An alert pilot sitting in the cockpit of an airliner waiting in line to takeoff spoke up on tower frequency and saved the day. Had a collision occurred this would have been one of the worst accidents in aviation history. Instead, it was the nearest of all near collisions. The A320 descended to 81 feet above the surface and missed the tail of an Airbus A340 by only 14 feet.
This event prompted then-National Transportation Safety Board (NTSB) Chair Robert Sumwalt to declare that “notams are a bunch of garbage, that no one pays attention to…” during a public hearing on the incident.
The Notam Alliance
The OpsGroup parses information from various sources and provides intel in the form of briefings to its membership in plain English.
The Air Canada event in San Francisco energized OpsGroup’s Zee to lead a crusade to fix the notam problem. The Notam Alliance, led by Zee, is an industry group made up of notam users and other experts which has identified five issues with the current notam system—let us call them the “five C’s.”
First, is the count, or number, of notams. The number of notams in a briefing packet is overwhelming. As Zee said, “We’re drowning in the data, but missing the message.” Worldwide, there will be over 2 million notams published this year.
Next is the formatting issue, everything is printed in CAPITAL letters. From a human-factors design perspective, this makes a notam difficult to read since each word appears as a block or rectangle. The origin of this problem dates to the early-1900s when the world communicated by telegrams.
The next issue, coding, is another carry-over from the telegraph. Categorization and abbreviations used to display critical flight information in notams are based on “Q-codes” from 1909 and the International Telegraph Alphabet (ITA-2) character set from 1924. Pilots often scratch their heads trying to decipher these codes.
Next, according to the Notam Alliance, is that there is a bunch of crap or junk presented in each briefing packet. Notams, as presented today, are all equally weighted, meaning the importance of the “lawnmowers adjacent to a runway” has the same weight as a runway being closed. Nothing is prioritized.
The final issue is control, since we must rely on a single source—the state (country) that issues the notam. According to Zee, notams are not always reliable—often the full story is missing. This was identified as a factor in the shootdown of Malaysia Airlines Flight 17, a Boeing 777, over Ukraine in July 2014 which killed 298 people.
Fixing Notams–the Super Notam!
According to the Notam Alliance, for almost 60 years there have been various attempts to improve the notam system with limited success. To fix notams, a key part of the Notam Improvement Act calls for the new system to be machine-readable, the information must be able to be filtered, and presented in a common language.
In February, members of this group began to ask the question: What do pilots want?
After eight weeks, a group (50 individuals) of notam end-users that included pilots, dispatchers, airlines, and other aircraft operators created a list of 50 tags. These tags were categorized into eight groups (for example: runway, taxiway, approach, or ATC), and then further subdivided into topics such as runway closed, runway lights, and runway length.
In March, the group ran weeks of tests using large language models (LLMs) such as ChatGPT 4 to demonstrate how well random notams could be understood by a machine. According to the Alliance, “the results show that artificial intelligence (AI) has reached a point that it can understand a notam with greater than 98 percent reliability.”
From May 8 to 12, the group ran a “sprint” to bring all of these developments together. In all, more than 300 people participated in the event. The goal, according to Zee, “was to design and test a prototype system to post-process notams, tag them, summarize them, and sort and filter them into a newly designed briefing package.”
The output of this exercise was the “Super Notam” using a tool that will become an open-source application. Once the notams are ingested, AI tags the notams and provides a summary using plain English. Next, rules are applied to sort the information using a matrix to match different airports, flight phases, and flight information regions, as an example.
The Super Notam briefing package has a primary and appendix section. The primary section includes all relevant operational notams. Everything else—the “dark notams”—is filed in the appendix. A dark notam follows the philosophy of the “dark cockpit,” where indicators and annunciations appear blank when they are operational.
The Notam Improvement Act of 2023 provides a path to provide a system that is stable and usable to improve safety in the NAS. According to AOPA senior v-p of government affairs Jim Coon, “These changes to the notam system are long overdue. AOPA appreciates the bipartisan effort to ensure pilots can feel safe operating in an accurate and updated system.”
