WASHINGTON -- Air traffic controller furloughs scheduled to kick in on Sunday could result in flight delays of more than three hours in Atlanta, as well as significant delays in Chicago, Los Angeles and New York-area airports, federal officials said Thursday.Transportation Secretary Ray LaHood and Federal Aviation Administrator Michael Huerta said they have no choice but to cut controller staffing by 10 percent, which will reduce how many planes airports can handle. But a spokeswoman for Airlines for America, a trade association for the airline industry, said that the furloughs are unnecessary and that airlines are considering suing the government.Without the furloughs, FAA officials could find no way to cut $637 million from the agency's budget as required by automatic across-the-board spending cuts approved by Congress, LaHood and Huerta said at a media briefing.Calling the automatic spending cuts "a dumb idea," LaHood said his department, which includes the FAA, has done "everything possible" to find the money."If we had had our way, we probably wouldn't be sitting here," he said. "This is a fluid situation, but we want the traveling public to have the best information."In the most extreme case, the furloughs could delay flights up to 210 minutes at Hartsfield-Jackson Atlanta Airport, depending upon time of day and other factors. The FAA said, however, that the average delay will be far less, about 11 minutes.Other airports for which officials provided delay estimates include Newark, with maximum delays of 51 minutes and average delays of about 20 minutes; John F. Kennedy in New York, with maximum delays of 50 minutes and average 12 minutes; LaGuardia in New York, with maximum delays of 80 minutes and average 30 minutes; Los Angeles International, with maximum delays of 67 minutes, and average 10 minutes, and Chicago O'Hare, with maximum delays of 132 minutes, average 50 minutes.Airports in Miami and Fort Lauderdale, Fla.; Charlotte, N.C.; San Diego; Philadelphia; and San Francisco, as well as Chicago Midway Airport, are also expected to experience significant delays, the officials said.The FAA did not provide estimates for delays at Dallas//Fort Worth Airport, and airport spokesman David Magana said airport officials did not know what the impact would be.The FAA's 47,000 employees -- including nearly 15,000 controllers -- are scheduled for one furlough day every other week through Sept. 30. Delay estimates vary because each airport is unique, Huerta said.Airline spokeswoman Jean Medina said the industry has legal opinions "affirming that the FAA has discretion to implement cuts without furloughing air traffic controllers."