ATLANTA , Georgia ( CNN ) -- Air traffic delays began to clear up Tuesday evening after computer problems left travelers across the United States waiting in airports , the Federal Aviation Administration said . Flights at Atlanta 's Hartsfield-Jackson International Airport were delayed Tuesday afternoon . Airports experienced hours of flight delays Tuesday afternoon after a communications breakdown at a Federal Aviation Administration facility , the administration said . The facility south of Atlanta had problems processing data , requiring that all flight-plan information be processed through a facility in Salt Lake City , Utah , overloading that facility . The two facilities process all flight plans for commercial and general aviation flights in the United States , FAA spokeswoman Kathleen Bergen said . Delays had begun to clear by 5 p.m . ET . By 6 p.m. , the administration said minimal delays remained as the Salt Lake facility began processing requests closer to normal speed . `` The situation is pretty much resolved , '' FAA spokeswoman Diane Spitaliere said . At about 9:30 p.m . ET , most major airports were reporting flights departing on time or with less than 15-minute delays . Newark International was still reporting delays of up to 1 hour and 45 minutes and LaGuardia Airport in New York reported 45-minute delays -- although weather problems were cited as the main problem . John F. Kennedy International in New York and Hartsfield-Jackson Atlanta International were reporting delays of up to 30 minutes , although both of those airports also had experienced thunderstorms and other weather-related difficulties . The administration said there were no radar outages and said it had not lost contact with any planes during the computer glitch . The roughly 5,000 flights that were in the air when the breakdown happened were not affected , just those that were waiting to take off . iReporter stuck in Philadelphia . `` This is really not a safety issue , this is an aggravation issue , '' CNN aviation expert Miles O'Brien said . Watch Miles O'Brien track the delays » . The problem appeared similar to a June 8 , 2007 , computer issue that caused severe flight delays and some cancellations along the East Coast . iReport.com : Are you stuck at the airport ? iReporter Stephanie McCauley sat on the tarmac for more than an hour at Baltimore/Washington International Airport on Tuesday on a flight bound for Albany , New York . `` It happens . It 's just weird , because you 're sitting , and you do n't know if it 's going to be 20 minutes or 2 hours , '' McCauley said . Cheryl Stewart , spokeswoman for Baltimore/Washington International Airport , said that as of about 3:40 p.m. , some flights were being allowed to take off , but the FAA was no longer accepting new flight plans . `` We 're just kind of waiting for further word , '' Stewart said . On the FAA 's Web site , delays were being reported at all 40 airports on the administration 's primary flight information map . The worst delays were in the Northeast , Bergen said . Chicago 's Midway and O'Hare airports in Illinois were reporting delays of up to 90 minutes . The Web site , which normally lists the length of expected flight delays , was no longer listing that information Tuesday afternoon . The total number of flights affected was unknown , although it was believed to be in the hundreds . Mark Biello , a CNN photographer sitting on a delayed flight at Hartsfield-Jackson International Airport in Atlanta on Tuesday afternoon , said flights there were being cleared for takeoff one at a time . Watch Mark Biello at the airport » . `` They 're releasing the planes but on a one-by-one basis , so it 's really backed the whole system up , at least in the Atlanta area , '' Biello said . At Philadelphia International Airport in Pennsylvania , iReporter Randy Hehn and his wife were on their way home to Denver , Colorado , after a trip to Europe . He said he 'd left Stockholm , Sweden , 11 hours earlier . `` I do n't really want to spend the rest of the evening in the airport ; I 'm hoping they get this fixed , '' Hehn said in a video posted on iReport.com . `` I see planes moving around , but I do n't know . `` We 're just coming back from Europe , we 're really tired , and this is bad news . ''
NEW : FAA says situation `` pretty much resolved '' FAA facility south of Georgia , Utah , having problems processing data . All flight-plan information must be processed by facility in Atlanta , Salt Lake City . Unknown number of flights delayed by glitch .