NEW YORK (AP) — The world’s largest aircraft fleet was grounded for hours by a cascading outage in a government system that delayed or cancelled thousands of flights across the U.S. on Wednesday.
The White House initially said that there was no evidence of a cyberattack behind the outage that ruined travel plans for millions of passengers. President Joe Biden said Wednesday morning that he’s directed the Department of Transportation to investigate.
Whatever the cause, the outage revealed how dependent the world’s largest economy is on air travel, and how dependent air travel is on an antiquated computer system called the Notice to Air Missions, or NOTAM.
Before commencing a flight, pilots are required to consult NOTAMs, which list potential adverse impacts on flights, from runway construction to the potential for icing. The system used to be telephone-based, with pilots calling dedicated flight service stations for the information, but has moved online.
The NOTAM system broke down late Tuesday, leading to more than 1,000 flight cancellations and 7,000 were delayed flights by midday Wednesday, according to the flight tracking website FlightAware.
The chaos is expected to grow as backups compound. More than 21,000 flights were scheduled to take off in the U.S. today, mostly domestic trips, and about 1,840 international flights expected to fly to the U.S., according to aviation data firm Cirium.
Airports in Chicago, Los Angeles, New York and Atlanta were seeing between 30% and 40% of flights delayed.
“We are going to see the ripple effects from that, this morning’s delays through the system during the day,” said Transportation Secretary Pete Buttigieg in an interview on CNN. “Now we have to understand how this could have happened in the first place. Why the usual redundancies that would stop it from being that disruptive did not stop it from being disruptive this time.”
Longtime aviation insiders could not recall an outage of such magnitude caused by a technology breakdown. Some compared it to the nationwide shutdown of airspace after the terror attacks of September 2001.
“Periodically there have been local issues here or there, but this is pretty significant historically,” said Tim Campbell, a former senior vice president of air operations at American Airlines and now a consultant in Minneapolis.
Campbell said there has long been concern about the Federal Aviation Administration’s technology, and not just the NOTAM system.
“So much of their systems are old mainframe systems that are generally reliable but they are out of date,” he said.
John Cox, a former airline pilot and aviation safety expert, said there has been talk in the aviation industry for years about trying to modernize the NOTAM system, but he did not know the age of the servers that the FAA uses.
He couldn’t say whether a cyberattack was possible.
“I’ve been flying 53 years. I’ve never heard the system go down like this,” Cox said. “So something unusual happened.”
According to FAA advisories, the NOTAM system failed at 8:28 p.m. Eastern on Tuesday preventing new or amended notices from being distributed to pilots. The FAA resorted to a telephone hotline to keep departures flying overnight, but as daytime traffic picked up it overwhelmed the telephone backup system.