NEW YORK - A day after flight delays plagued much of the nation, air travel was smoother Tuesday, but the government warned passengers that the situation could change by the hour as thousands of air-traffic controllers are forced to take furloughs because of budget cuts.
Meanwhile, airlines and members of Congress urged the Federal Aviation Administration to find other ways to reduce spending. Airlines are worried about the long-term costs late flights will have on their budgets and on passengers.
"I just can't imagine this stays in place for an extended period of time. It's just such terrible policy," US Airways CEO Doug Parker said. "We can handle it for a little while, but it can't continue."
The delays are the most visible effect yet of Congress and the White House's failure to agree on a long-term deficit-reduction plan.
Transportation Secretary Ray LaHood said no one should be surprised, noting that he warned about the potential for problems two months ago.
His solution: Blame Congress for the larger budget cuts that affected all of government, including a $600 million hit to the Federal Aviation Administration.
"This has nothing to do with politics," LaHood said. "This is very bad policy that Congress passed, and they should fix it."
Critics of the FAA insist the agency could reduce its budget in other ways that would not inconvenience travelers.
Sens. John D. Rockefeller IV, a West Virginia Democrat, and John Thune, a Republican from South Dakota, sent a letter to LaHood on Monday accusing the FAA of being "slow and disturbingly limited" in response to their questions. They suggested the FAA could divert money from other accounts, such as those devoted to research, commercial space transportation and modernization of the air-traffic control computers.
Others in Congress urged the Obama administration to postpone the furlough for at least 30 days.
In the past five years, the FAA's operating budget has grown by 10.4 percent while the number of domestic commercial flights has fallen 13 percent.
"There's no cause for this. It's a cheap political stunt," said Michael Boyd, an aviation consultant who does work for the major airlines.
The FAA says the numbers aren't so clear cut. In that time, the government has signed a new, more expensive contract with air traffic controllers, added 400 new aviation safety inspectors and beefed up its payroll to deploy a new air traffic-control computer system.
So given the budget cuts, FAA officials say they now have no choice but to furlough all 47,000 agency employees - including nearly 15,000 controllers - because salaries make up 70 percent of the agency's budget. Each employee will lose one day of work every two weeks.
Planes will have to take off and land less frequently, so as not to overload the remaining controllers on duty.
About 400 delays piled up Sunday and another 1,200 Monday that were linked to the furloughs.
Delays were minimal for most of Tuesday. But during the afternoon rush, delays of one to two hours started to mount in New York and Washington. Flight-tracking service FlightAware expected them to last through the evening. Los Angeles and Dallas saw delays of less than an hour.
Travel has not yet reached the levels the FAA warned about where some airports - like those in Atlanta or New York or Chicago - could see delays of more than three hours. Mother Nature has so far cooperated.
"Bad weather would make this much worse," Parker added.
There's also potential that passengers will be scared away by fears over delays. Many families are now planning summer vacations and might choose a driving trip instead.
If the FAA staffing shortage persists into the summer, airlines will also have less flexibility to ease passengers' pain.
For instance, Delta Air Lines canceled about 90 flights Monday because of worries about delays. Just about every passenger was rebooked on another Delta flight within a couple of hours, according to Ed Bastian, Delta's president.
In the busy summer travel months, the airline might not have enough empty seats to accommodate passengers from canceled flights.
Summer also brings thunderstorms, which are the biggest source of airline delays. Unlike snowstorms, which are forecast days in advance, thunderstorms can develop quickly and are unpredictable.
"This is just the beginning of what promises to be a huge economic disruption," the National Air Traffic Controllers Association warned in a statement Tuesday. "This is no way to run the world's safest, most efficient national airspace system. Controllers continue to do their best every day to keep the system running. It's time policymakers show the same amount of effort and dedication."
The federal budget cuts are also eating into the company's bottom line, with defense company employees cutting their flight budgets by 20 percent in the last month.
US Airways operates a hub at Washington National airport, and government business accounted for 3 percent of its revenue last year. Government revenue dropped 37 percent in March because of the spending cuts and the timing of Easter, Kirby said.
Unlike Delta, US Airways didn't cancel flights in advance.
"It's really difficult to do because we don't know where the issues are going to be until the issues are there," said the airline's president, Scott Kirby.