The situation was caused by an outage in a critical system used by the FAA to distribute real-time data and alerts to pilots. Known as NOTAMs (Notice to Air Mission), the system is vital to information sharing and coordination of many of the basic logistics of safe flight.
According to DO, the flight suspension went into effect “to allow the agency to validate the integrity of flight and safety information.” The agency said it wasn’t immediately clear what caused the NOTAM to go out of business. The White House She said this morning that there was no evidence that the system blackout was caused by a cyber attack, but was directing the Department of Transportation to conduct a thorough investigation into what caused the crash.
“This event today is more significant than a hurricane hitting the United States, more significant than a blizzard closing an airport,” Michael McCormick, an assistant professor at the Embry-Riddle Aeronautical College of Aviation, told reporters. University. conference after the accident. “This has had a system-wide impact across the country.”
NAV Canada, a non-profit corporation that serves as the Canadian counterpart to the FAA, said today it also experienced a brief outage to the NOTAM system. Brian Boudreau, a spokesman for the company, says he was investigating the “root cause of the failure,” but that he didn’t believe the issue was related to previous FAA issues.
The NOTAM system is decades old and widely criticized by pilots for being cumbersome and inefficient. NOTAM notices can be tens or even hundreds of pages long and are written in a kind of parallel coded language that has evolved over many years and from numerous technologies, including Morse code, telegrams, and the radio navigation system Loran-C.
NOTAMs often include the same notice repeated over and over, plus non-essential details that auto-populate in the system over weeks or months. A federal investigation found that it was a difficult-to-read NOTAM likely responsible for a 2017 incident in which an Air Canada plane nearly collided with four different planes as it landed on a San Francisco runway.
“The way they’re written in weird, hard-to-read code could definitely be improved,” says a pilot at a major commercial airline who asked not to be named because he’s not authorized to speak to the press. “And if you look at your release, sometimes there’s, like, 80 NOTAMs, and you have to look closely at the dates and times to make sure they’re still applicable.”
The FAA has been working for years on a Modernization effort of the NOTAM which is still ongoing. A system that once worked on printouts and calls to a centralized flight service number has transitioned to a cloud-based platform over the past decade. The agency is still working to integrate the US system into the one used by all international civil aviation authorities. But “the aviation system is a complex network of networks,” McCormick says, and its complexity only increased as the system moved from a wired system to a wireless system. He adds that it was designed to be redundant, so in theory, the entire critical system won’t shut down just because part of it experiences an outage. Usually, says McCormick, “you can switch to different nodes to avoid problems. Why it didn’t work in this case is not yet known.
The outage could indicate deeper problems in the digital system that underpins US transportation infrastructure. But McCormick says Wednesday’s ground shutdown demonstrates the FAA is prioritizing flight safety and is able to take whatever protective measures are needed. “There’s absolutely no need to panic,” he says. “I would feel quite comfortable getting on a plane today and flying across the United States.”