FAA issues ground stop at airports nationwide, including Philadelphia International Airport

The Federal Aviation Administration issued a nationwide ground stop at airports, including Philadelphia International Airport, due to "extraordinary circumstances and for safety reasons."

"The @FAAnews issued a nationwide ground stop for all U.S. airports following a communication issue impacting all Air Route Traffic Control Centers. FAA technicians are investigating the issue," Transportation Secretary Sean Duffy wrote on X. "We will provide immediate updates as we have them."

Homeland Security Secretary Markwayne Mullin told reporters outside the White House that there wasn't any indication yet that "this was a nefarious act against us. It was just a telecommunication outage, as of right now."

As of 5 p.m. Friday, data from FlightAware shows a total of 304 delays at Philadelphia International Airport and 22 cancellations.

"The FAA has issued a nationwide ground stop for departing flights at PHL and other U.S. airports due to an equipment outage," PHL wrote on X. "Contact your airline for the latest flight information."

Arthur Wolk, an aviation expert and pilot, said he thought it might be a computer hack when he first heard the news.

"The air traffic control system is computer-based. Everything about it works through a computer system, so if that system fails one way or another, the system is affected to such an extent that you can have sorts of air traffic difficulties," Wolk said. "Delays, difficulties getting clearances, difficulties communicating, things of that nature. So that surprises me that the government hasn't indicated a computer hacking issue."

This is a developing story and will be updated.