Air travelers started their week with a groan over delays caused by employee furloughs and bad weather.
On Monday, more than 1,200 delays were attributable to staffing reductions, and another 1,400 to weather and other factors, according to a statement from the Federal Aviation Administration.
The furloughs - triggered by sequestration cuts - went into effect Sunday, affecting all 47,000 FAA employees, including 15,000 controllers, who will lose one day of work every other week.
Controllers have responded to the staffing shortfall by spacing planes farther apart and halting all training and modernization projects. The overtime that will have to be paid to controllers at some of the country's busiest airports may eliminate any sequestration savings, according to the National Air Traffic Controller Association.
"We're on the side of travelers," Doug Church, spokesman for the National Air Traffic Controller Association, told ABC News. "You cannot move the same amount of planes, with fewer people, with the same efficiency without risks, and we're not going to risk safety."
The FAA indicated that delays of more than three hours were expected at the busiest U.S. airports as summer travel approaches.
Other variables, such as sick days for the remaining controllers and inclement weather, will also make for delays.
"There's going to be no way to identify what are and are not furlough related," Church said. "You don't have as many people that are working when other things happen as efficiently as they can."
Airlines for America, an industry group, along with the Air Line Pilots Association and the Regional Airline Association, has taken legal action in U.S. Appellate Court for the District of Columbia Circuit, in an effort to halt the furloughing of air traffic controllers. The court denied the motion for a stay last Friday, citing that the petitioners had not satisfied the requirements for a stay pending court review.
The A4A is seeking legislation that would deem air traffic controllers essential, and therefore not subject to furlough, according to a statement on its website.
As it stands, the roughly 2 million airline passengers who fly in the U.S. every day should check flight delay information before heading to the airport.