What caused so many flight delays and cancellations in the US on Sunday? It wasn’t the weather, or air traffic control; rather, it was an issue with the flight management system that airlines use to schedule their flights and communicate with airports. The glitch meant that airlines and pilots couldn’t always see each other’s schedules, causing thousands of flights to be delayed or canceled at the last minute. If you’re worried about missing your flight today because of the system failure, we have tips that can help you get where you need to go.

As of Sunday, airline cancellations and delays have been widespread across the United States.
To put it bluntly, over 912 flights have been canceled to date as of Sunday according to FlightAware.
Altogether, there have been 6,378 flights delayed across the United States.

Approximately 12% of flights at Chicago O’Hare were canceled on Sunday, and over 40% were delayed. On Sunday, Chicago saw heavy rain, with flash flood warnings in place for parts of Cook County during the afternoon.


Weekend of cancellations

On Saturday, there were 657 cancellations and 7,267 delays within, into and out of the United States.

4% of American Airlines’ flights were canceled and 24% of its Saturday flights were delayed, according to FlightAware.
United had 4% of its flights canceled, and 23% of those it did take off were delayed, the tracker noted. Second worst was Delta with 2% canceled and 22% of its Saturday flights delayed.

According to the website, 41% of JetBlue flights and 36% of Southwest flights were delayed on Saturday.