Flights are being cut at 40 of America’s busiest airports to offset air traffic controller shortages in what’s become the longest government shutdown in U.S. history. But it’s not just those travelers who will be affected by the cancellations.

“There's going to be extensive disruption across the entire nation’s air transportation system,” said Henry Harteveldt, and airline industry analyst and president of Atmosphere Research Group, an independent travel analytics firm. And the consequences could last longer than the shutdown.

Here’s what travelers should know as the cancellations begin taking effect Nov. 7.

The Department of Transportation and Federal Aviation Administration directed a 10% reduction in flights at 40 airports.

“It's going to be a step-up, phased-in approach to cutting flights,” Harteveldt said. “It will start Friday with a 4% cut to flights ... and it will step up from there to 10%.”