The failure primarily affected air travel out of airports serving East Coast cities such as Atlanta, Boston, New York, and Philadelphia. The impact on West Coast cities is believed to have been minimal.
As of 8:30am PT, the FAA's Flight Delay Information map showed all green for destinations in the Western half of the United States.
During the outage, flight plans were being processed manually.
"Air traffic controllers on the ground at major airports are getting no automated flight plan information and have to enter that information manually, a cumbersome and time-consuming process," said the National Air Traffic Controllers Association in a statement.
Flight plan information includes an airplane's destination, its type, and its speed.
"This is not a safety issue," said an FAA spokesperson via e-mail. "We have radar coverage and communications with planes."
The spokesperson said that the agency was investigating the cause of the problem.
The NATCA said that the problem was a failure of the National Airspace Data Interchange Network, which handles computerized flight processing plans for every flight in the country. The system is located in two locations -- Atlanta and Salt Lake City -- and the NATCA said that it failed in both locations.
"[There] will be flight delays throughout the day due to the "ripple effect" of this outage," the ATCA said.
ATCA also said that weather equipment is affected, meaning that NOTAM alerts (Notice to Airmen) were not being processed.