Air Canada and WestJet are encouraging travellers headed to or from the U.S. to check on their flights before going to the airport.
A cascading problem with a key computer system has led to outages at the U.S. Federal Aviation Administration, causing thousands of flights across the U-S to be either cancelled or delayed.
It followed a break-down of a government system that offers safety and other information to pilots.
WestJet says at least six of its flights were delayed because of the computer outage but none were cancelled while Air Canada said the outage would have an effect on its transborder operations.