The United States Federal Aviation Administration today halted flights departing across the country beginning early this morning and continuing until 9 a.m. ET. The pause — the first of its kind in the US since the September 11, 2001 attacks — delayed thousands of flights and spawned a cascade of further delays and cancellations throughout the day. Those familiar with the FAA’s systems say the outage is unprecedented, but ends years of frustration as the agency works to transition its complex processes to the cloud.
The situation was caused by a malfunction in a critical system the FAA uses to distribute real-time data and warnings to pilots. Known as NOTAM (Notice to Air Mission) alerts, the system is vital for sharing information and coordinating much of the basic logistics of safe flying.
According to the FAA, the flight interruption was put into effect “to allow the agency to validate the integrity of flight and safety information.” The agency said in an update tonight that a preliminary investigation had traced the failure to “a corrupted database file.” The White House said this morning that there was no evidence that the system outage was caused by a cyber-attack, but ordered the Department of Transport to conduct a thorough investigation into the cause of the incident.
“Today’s event is more important than a hurricane making landfall in the U.S., more important than a blizzard shutting down an airport,” Michael McCormick, an assistant professor in the College of Aviation at Embry-Riddle Aeronautical University, told reporters at a press conference. conference after the incident. “This had system-wide implications for the entire country.”
NAV Canada, a non-profit organization that serves as the FAA’s Canadian counterpart, said today it had also experienced its own brief NOTAM system outage. Brian Boudreau, a spokesman for the company, says it was investigating the “root cause of the outage” but did not believe the problem was related to the FAA’s previous problems.
The NOTAM system is decades old and widely criticized by pilots for being cumbersome and inefficient. NOTAM warnings can be dozens or even hundreds of pages in length and are written in a type of coded parallel language that has evolved over many years from numerous technologies, including Morse code, telegrams, and the Loran-C radio navigation system.
NOTAMs often contain the same warning repeated multiple times, as well as non-essential details that are automatically populated into the system over weeks or months. A federal investigation found that a hard-to-read NOTAM was likely responsible for a 2017 incident in which Air Canada planes nearly collided with four different planes as it landed on a San Francisco runway.
“The way they’re written in the weird, hard-to-read code could definitely be improved,” said a major commercial airline pilot who requested not to be named because they’re not authorized to speak to the press. “And when you look at your release, sometimes there are like 80 NOTAMs, and you have to look closely at the dates and times to make sure they still apply.”
