The US Federal Aviation Administration (FAA) lifted a nationwide ground stop imposed on Friday that halted outbound flights, an order it issued citing “extraordinary safety reasons and circumstances.” The suspension, which grounded thousands of flights across the country, was lifted on Friday night. Recommended Stories list of 3 itemsend of list This was the third nationwide ground stop of all sorties since the attacks of September 11, 2001, Mullin said, adding that this was not “another 9/11.” Here’s what we know: What happened? The FAA issued a nationwide ground stop at 3:54 p.m. ET (20:54 GMT) on Friday due to a telecommunications outage that affected air route traffic control centers, which handle flights traveling across the country. The FAA confirmed that the nationwide ground shutdown had been lifted. (01:15 GMT on Saturday), after more than four hours of interruption. “We have opened the airspace,” Duffy said, warning that flights would not resume immediately. “It’s going to be slow,” he added, urging passengers to check with their airlines. Duffy said flights would resume depending on the availability of pilots and flight attendants, and authorities would try to get as many flights moving as possible by Friday night. Aviation analytics firm Cirium said that after 4 p.m. ET (2100 GMT) on Friday, some 11,000 flights carrying more than 1.5 million passengers were still scheduled to depart U.S. airports. As of 7:05 p.m. ET (00:05 GMT Saturday), at least 827 flights had been diverted, according to Cirium. Of them, 670 returned to their departure airports, while 157 were diverted elsewhere. Planes already in the air were allowed to continue to their destinations and land during the ground stop. During the grounding, international flights were handled on a case-by-case basis, with some allowed to take off despite the restrictions. How many flights were affected? More than 4,700 flights were canceled and 10,000 delayed on Friday, while another 700 had already been canceled by Saturday, according to FlightRadar24. Aviation analysts said it could take days for airlines to restore their schedules. Reporting from Los Angeles International Airport, Al Jazeera’s John Hendren spoke with passenger Nicholas Erdodi, who traveled from New Zealand and was trying to get to Chicago for a conference. Erdodi said he had been traveling for between 16 and 18 hours before spending another six hours at the airport, where passengers had been forced to abandon their plane. “The challenge is that you can’t ask anyone here what to do,” he told Al Jazeera. “The lack of information is what bothers me, I mean, not to mention finding the hotel to spend the night, not to mention all the cost.” Erdodi said his reservation had been changed, but he was not sure if his next flight would leave. “I work in technology, I understand what might be happening, but someone has to tell us,” he said. “It doesn’t matter if someone tells us we don’t know what’s going on, but please let us know what’s going on,” he added. What does a ground stop mean at the national level? A nationwide grounding temporarily requires departing aircraft to remain on the ground until they are cleared to take off. Flights in the air are generally allowed to continue to their destination, but new departures have strict orders to remain grounded. The move is aimed at preventing more planes from entering the airspace while authorities deal with safety issues. What caused the FAA’s nationwide grounding? The FAA said the ground stop was caused by a telecommunications outage that affected air traffic control systems. Duffy said the outage was caused by switches and routers becoming overloaded with data and going down, adding that the incident did not involve a complete loss of communications or radar capabilities. Todd Curtis, aviation security expert and CEO of AirSafe.com, told Al Jazeera that the failures appeared to be concentrated in the country’s air route traffic control centers. “There are 21 across the United States, one in Alaska and the other 20 in the lower 48 states,” he said. “These are the people who run the whole aviation community is built on redundancy,” he told Al Jazeera. “So the fact that a redundant system wasn’t activated immediately just raises more questions than we’ve seen answered at this stage.” Mullin said there was no cyberattack related to the grounding nationwide and the public was never in danger. Duffy acknowledged that tens of thousands of travelers had been stranded and asked for $50 billion. in improvements to the country’s air traffic control system. When will U.S. flights return to normal? Duffy said “it will take us some time to get back to capacity,” but he expected operations to “be back up and running as we hit the heat of travel over Thanksgiving.” This period, which begins in less than two weeks, is typically one of the busiest times of the year for U.S. air travel. passengers even after the technical issues were resolved. “If it is completely resolved, it would take more than a day to get back to normal and reschedule the planes,” he explained to Al Jazeera. “Many airlines operate interconnected networks, which means passengers often have to change planes at major hubs,” he said. Passengers have been advised to check their flight status directly with their airlines as delays and cancellations could continue.
