The FAA lifted, at 9 a.m. on the east coast of the country (2 p.m. GMT), the ban preventing all take-offs and affirms in a tweet that “normal air traffic operations are gradually resuming” across the country.

She had already warned that flights could resume at that time, once the problems affecting a crucial information system for pilots and crews were resolved.

The outage began overnight from Tuesday to Wednesday.

The FAA clarified "to continue to investigate the cause of the initial problem".

All domestic flights departing from the United States had to be suspended until 9:00 a.m., with the exception of Newark Liberty airports (western suburbs of New York) and Atlanta, where flights were able to resume earlier to avoid excessive traffic congestion.

Asked about the subject, US President Joe Biden said he spoke with his Minister of Transport, Pete Buttigieg, but did not know the origin of the breakdown for the moment.

An employee at Los Angeles International Airport walks past a plane docked at a gate on January 11, 2023 © Stefani Reynolds / AFP

"Planes can still land safely, but not take off at this time," Biden said before the takeoff ban was lifted.

Regulators "don't know what the cause is, they expect to have a better idea in a few hours and will react then," he added.

White House spokeswoman Karine Jean-Pierre said on Twitter that at this stage there was "no sign that this was a cyberattack".

From Baltimore to Ottawa

Several airports in North America (Ottawa, Baltimore, Austin, Boston...) had warned that delays were to be expected and asked travelers to check the status of their flight before going to the airport.

The American company United Airlines confirmed in a message sent to AFP that the FAA had lifted the suspension and that its operations had resumed.

"Customers may continue to experience delays and cancellations as we work to reinstate our program, and should check" the company's app or site for the latest information on their flight, United adds.

"We are monitoring the situation closely and working with the FAA to minimize disruption to customers," American Airlines said in a separate statement.

Passengers wait near their gate at Los Angeles International Airport on January 11, 2023 © Stefani Reynolds / AFP

This episode of disruptions in American airports comes some time after a great chaos triggered at Christmas time by a wave of extreme cold accompanied by snowfall, and which had been prolonged for several days by cascading cancellations within the Southwest company.

The Notice To Air Missions (NOTAM) system, affected by Wednesday's outage, provides information to aircrew about risks, airport developments and other critical information.

This system is "essential in the information required for the conduct of ground / air operations", explained to AFP Michel Merluzeau, analyst for the AIR cabinet.

"This may include airport information, special activities like military operations, or temporary flight restrictions," he continued.

There were nearly 4,600 delayed flights in the United States as of 9:25 a.m. (2:25 p.m. GMT) on the country's east coast, according to flight tracking site Flight Aware.

The number of delays being related to the outage was unclear.

A total of 21,464 flights are expected to take off from the United States on Wednesday, the vast majority being domestic routes, according to figures from specialist firm Juliett Alpha.

Around 2 million passengers are potentially affected by the incident.

US Transportation Secretary Pete Buttigieg said on Twitter that he had called for an investigation "to determine the causes (of the breakdown) and recommend next steps".

© 2023 AFP