As many as 1,800 flights could be affected on Friday alone, according to Cirium, an aviation-data provider. The final figure will depend on which airports are targeted. The FAA estimates that it handles an average of more than 44,000 flights a day.

Airlines are canceling hundreds of flights to comply with the FAA's order. But there are still questions about the plan, which the agency says will keep the skies safe during the government shutdown.

The federal government shutdown, now in its 38th day, prompted the Federal Aviation Administration to issue a temporary emergency order Thursday prohibiting commercial rocket launches from occurring during “peak hours” of air traffic.

Beginning next week, daytime rocket launches are all officially scrubbed thanks to the government shutdown.

UPDATE: 3:40 p.m.: Austin-Bergstrom International Airport announced the FAA had lifted its ground delay as of 3:34 p.m. However, George Bush Intercontinental and Houston Hobby are both seeing ground delays of 46 minutes and 2 hours 46 minutes respectively, according to the FAA.

The Federal Aviation Administration (FAA) issued an emergency order restricting air carrier operations at 40 airports, which could impact travelers going to and from Erie International Airport. That list includes airports in Tampa,

Sara Nelson, president of the Association of Flight Attendants, joins Morning Joe as hundreds of flights are canceled amid the ongoing government shutdown, warning the system is “unsustainable” and that people “will break” if air traffic workers remain unpaid.

TSA wait times at George Bush Intercontinental Airport were expected to exceed 45 minutes to an hour, according to airport officials.