The U.S. aviation warning system that crashed for more than an hour Wednesday traces back its origins to ocean-faring ships and has been under continuous reforms for years, experts say.
At least one aviation industry group has called for it to be replaced altogether.
The Federal Aviation Administration grounded all flights blaming an unspecified failure in the Notice to Air Missions (NOTAM) system. NOTAM issues a near-constant stream of acronyms and abbreviations to alert pilots to a host of potential dangers, everything from parachuters and bad weather to legal airspace restrictions and flocks of birds.
By Wednesday evening, the agency had pinpointed the problem to a damaged database file, and there is no evidence of a cyberattack, it said.
The White House also said it saw no signs that the NOTAM system was taken down as a result of a cyberattack. The Department of Transportation was conducting a “full investigation” into its root cause.
Transportation Secretary Pete Buttigieg said the outage lasted approximately an hour and a half, but the FAA’s website that lists NOTAMs was only intermittently accessible through Wednesday afternoon.
Regardless of the cause of the failure, the NOTAM system has long been a source of frustration for pilots and others in the aviation industry who say it overloads them with information that’s irrelevant to their flight and makes it difficult to identify actually useful information.
NOTAM notices rely on a complex string of codes and abbreviations that share information like dates and locations of potential issues for a pilot to read before a flight.
NOTAMs are modeled after a similar warning system for ships, which the U.S. Navy began publishing in print in 1869. Aviation authorities began issuing NOTAM warnings via telecommunications channels in 1947.
As U.S. aviation grew, so did a glut of NOTAM warnings delivered to pilots before each flight, said Thomas Anthony, the director of the University of Southern California’s Aviation Safety and Security Program. And each of those airports can provide information that makes its way to NOTAM.
“To give you an idea, there are 13,512 airports in the United States,” Anthony said.
“The complexity of the system is mind-boggling,” he added.
In 2018, Robert Sumwalt, then the board chair of the U.S. National Transportation Safety Board, said that NOTAMs had become “just a bunch of garbage that nobody pays any attention to.”
That year, Congress passed a bill requiring the FAA to reform the NOTAM system, including by creating a machine-readable interface to give pilots and other flight professionals the option to streamline their delivery.
That process, which is still ongoing, requires multiple types of old software programs to communicate with each other.
The status of the FAA’s NOTAM reform isn’t clear, and the FAA didn’t respond to a request for comment about it. They are “still ongoing,” Anthony said.
David Mumford, a spokesperson for OPS Group, said in an email that for safety’s sake, it was likely necessary to ground flights if NOTAM had stopped functioning.
But its failure Wednesday only highlighted his group’s cause, he said.
“Once again, we get to see how antiquated and vulnerable the Notam system is!” he said.