From The New York Times:
A wave of flight cancellations hit the United States on Friday, bringing home the effects of the government shutdown to many more Americans, though major airports appeared to be working largely as normal in the morning.
The cuts were announced by Federal Aviation Administration this week to limit air traffic as the shutdown, now the longest in U.S. history, leaves air traffic controllers working without pay. Major airlines said that most customers would not be affected and that travelers who wanted to change or cancel a flight for a refund could do so. International flights were unlikely to be affected.