Better discussion from Canadian news source https://www.cbc.ca/news/us-air-travel-chaos-notam-outage-1.6710734 https://www.cbc.ca/news/us-air-travel-chaos-notam

Better discussion from Canadian news source https://www.cbc.ca/news/us-air-travel-chaos-notam-outage-1.6710734 https://www.cbc.ca/news/us-air-travel-chaos-notam-outage-1.6... NAV Canada said it didn't think it was related to U.S., but investigating.