Forced landing

Thousands of U.S. flights were canceled or delayed after a glitch in a system that provides pilots with safety-related information.

The government launched an investigation into the failure, which left some planes unable to depart for several hours.

The Federal Aviation Administration (FAA) said preliminary reports indicated that “a corrupt database file was the cause of the failure.”

The agency said it would take steps to avoid similar failures in the future.

The failure showed how much U.S. air travel depends on the NOTAM (Notice to Air Missions) computer system that sends notifications to pilots.

Before takeoff, pilots and airline dispatchers must review these notices, which contain information about weather conditions, runway closures and other timing factors that can affect a flight.

The system used to be phone-based, but has been web-based for years.

The system malfunctioned Tuesday evening and was not restored until mid-morning Wednesday. The FAA took the rare step of banning flights for a while, and the growing chaos has led to the cancellation of more than 1,300 flights and the delay of 9,000 others, according to FlightAware, a flight-tracking website.

Transportation Secretary Pete Buttigic said at a news conference that the problems “led to a flight ban because of the way flight safety information was spread through the system.”

He warned that travelers could still feel some of the effects of the glitch after the system was restored.

Buttigic said his ministry would try to figure out the causes of the system failure.

Experts who have worked in the aviation industry for many years don’t recall such a disruption caused by a technological failure. Some believe it is comparable in scope to the nationwide airspace shutdown following the 2001 terrorist attacks.

“There have been occasional localized problems here and there, but historically this is a pretty significant case,” said Tim Campbell, former senior vice president of air transportation at American Airlines, who now works as a consultant in Minneapolis.

President Joe Biden said Buttigich informed him of the incident.

The Senate Commerce Committee will examine the causes of the FAA computer system failure, committee chair Maria Cantwell said Wednesday.

“We will find out what caused the failure and how redundancy plays a role in preventing future failures. The public needs a sustainable air transportation system,” Cantwell said.

Many lawmakers from both parties have called for action to prevent future failures.

“The FAA’s failure to maintain an important safety system is completely unacceptable,” said Senator Ted Cruz, the committee’s incoming chairman.