The Federal Aviation Administration's order to scale back flights nationwide because of the government shutdown is now in effect.

Flights at 40 major airports including in New York, Los Angeles and Chicago are being cut Friday.

FlightAware says airports in Chicago, Atlanta, Denver, Dallas and Phoenix led the way with the most disruptions so far.

Travelers arriving to and from Chicago's O'Hare International Airport reacted to the flight cancellations and the shutdown.

"I'm a little annoyed, but I also understand that we need to be safe and we need to have air traffic controllers staffed, and if there's not full staffing you know I'd rather some of us have to have a flight cancelled here and there than be unsafe," said Connor Riddell, who is traveling from Chicago and wondering if he might have to drive home from his destination.

The FAA says its goal is to reduce flights by 10% by next weekend to ease pressure on unpaid air traffic controllers. Hundreds scheduled for Friday already have been canceled.

The impact is expected to be felt across the U.S. air transportation system, affecting passengers and package deliveries.