The Edmonton International Airport (YEG) says six out of seven of its U.S.-bound flights were cancelled on Friday because of a ground stop issued in the United States by the Federal Aviation Administration. U.S. Transport Secretary Sean Duffy said in a social media post that planes have been grounded due to a “communication issue” impacting all U.S. Air Route Traffic Control Centers. There are several flights scheduled to depart to the U.S. from Edmonton on Friday, according to an airport spokesperson. “As this is an evolving situation, passengers travelling to the United States today should check directly with their airline for the latest information on their flight before coming to the airport,” YEG spokesperson Erin Isfeld wrote in an email to CTV News Edmonton. It’s unclear how long the ground stop will last.