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.

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 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.

Only two flights have been canceled so far at McGhee Tyson on Nov. 7. Knoxville, so far, has avoided the brunt of the government shutdown impacts on airports. Unlike other Tennessee airports, like Nashville International Airport, long security lines and delays have been minimal.

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

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.