President Donald Trump was briefed within 30 minutes of a nationwide FAA ground stop that left thousands of flights cancelled and travellers stranded across the United States.
The Federal Aviation Administration ordered all aircraft to remain on the ground at 3.36pm on Friday, while about 3,500 planes were already in the air. Medical services flights were allowed to continue to their destinations.
Federal agencies including the FBI, Department of Homeland Security, Transportation Department, Justice Department, Defence Department, US Cyber Command and the Federal Emergency Management Agency were brought into discussions within minutes of the disruption.
Transportation Secretary Sean Duffy said the stoppage was necessary because of “a communication issue impacting all Air Route Traffic Control Centers”. FAA technicians were investigating the problem, he said.
The intelligence community subsequently found no indication of hostile activity after checking its channels for suspicious communications. Mr Trump, who was attending an economic policy meeting, was briefed by senior staff and passed instructions to officials involved in the response.
A White House call led by chief of staff Stephen Miller was used to coordinate the response. Mr Trump later met Mr Duffy and Homeland Security Secretary Markwayne Mullin, while also contacting congressional leaders about securing more funding for the FAA and modernising air traffic control systems.
FAA ground stop lifted after four hours
The grounding was lifted after four hours, once the problem had been identified. Flight tracking figures recorded about 9,159 cancellations and 7,190 delays on Friday.
At a news conference on Saturday, Mr Duffy said the disruption appeared to have begun during maintenance work by FAA telecommunications contractor L3Harris Technologies at a remote facility. Ageing copper communications lines were being replaced with fibre-optic connections when a router began making more than 1,000 connection attempts every four to five seconds, overwhelming routers across the FAA network.
Mr Mullin and Mr Duffy were more than 30 minutes late to a planned press conference on Friday evening because they were close to restoring the system and did not want to interrupt the effort, officials said.
Although officials have identified a likely sequence of events, important questions remain about the underlying cause of the system-wide failure.
The Homeland Security Council has invited senior government officials and outside stakeholders to a meeting on Monday to discuss the next steps and how to prevent a repeat disruption while modernisation work continues.
