FAA issues nationwide ground stop due to "extraordinary circumstances"

The FAA issued an extremely rare nationwide ground stop at all airports due to "extraordinary circumstances" and "reasons of safety."

The big picture: An air traffic control advisory posted Friday afternoon reads: "All departing traffic should remain ground stopped until further notice."

• "Inbound international flights will be managed on a case by case basis."

What they're saying: "The FAA issued a nationwide ground stop for all U.S. airports following communication issues impacting multiple Air Route Traffic Control Centers," the agency said in a statement.

• "FAA technicians are investigating the issue. We will provide updates."

Homeland Security Secretary Markwayne Mullin told reporters at the White House Friday evening that there's no indication of a "nefarious attack."

• The FBI is probing whether the problems were caused by a software update gone bad, Bloomberg reports.

How it works: Air Route Traffic Control Centers, often simply called "centers," mostly handle high-altitude en route airspace between airports.

Between the lines: The FAA has been rolling out a new AI tool designed to help manage airspace congestion, but it's unclear if that system has any connection to Friday's communication issues.

• The developer of that tool denied any connection, though.
• The nationwide ground stops are also preventing NTSB investigators from reaching the scene of Friday's collision between a Mississippi River cruise ship and a tanker in New Orleans, Rep. Troy Carter (D-La.) told a local station.

💭 Our thought bubble, from Axios aviation expert and pilot Alex Fitzpatrick: With no planes departing anywhere, airports nationwide may quickly run out of gates and room for the thousands of flights navigating the crisis while already airborne.

The bottom line: It's likely going to be a messy night — and the effects could easily spill over into the weekend.

This is a breaking news story and will be updated.