Follow live updates as flight reductions begin today at 40 high-traffic airports in what officials have described as a "proactive" effort to alleviate pressure points.

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.

American Airlines said that the 4% reduction will mean 220 canceled flights per day. The vast majority of impacted American Airlines flights are regional, and there’ll be no impact to international flights including Mexico, Canada and the Caribbean, CEO David Seymour said in a letter to employees. Further hub-to-hub routes impact will be minimized.

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

As the longest government shutdown in U.S. history drags on, airlines have been ordered to begin reducing operations on a phased-in basis.

FLETCHER – The Asheville Regional Airport was relatively quiet and uncrowded Nov. 7, the first day after a Federal Aviation Administration mandate to reduce flights out of certain airports.