Sunday brought flight delays as long as three hours to at least one airport, the result of staffing shortages brought on by federal sequester cuts and resulting furloughs.
There were flow-control programs, or efforts to manage traffic, in effect for the Charlotte, N.C., airport as well as for airspace over northern Florida Tuesday afternoon. The Federal Aviation Administration attributed the constraints in part to staffing shortages, according to flight tracking web site FlightAware.com.
At 5 p.m. today, the FAA website showed traffic to all New York-area airports as " delayed at its departure point." Travelers flying into these airports should check with their carriers about delay specifics. It is unclear if these delays are all because of sequester cuts; the number of flights was also likely a contributing factor.
ABC News has learned that controllers were putting extra air space between flights because there were fewer air traffic controllers.
Denver, Charlotte and Miami airports also experienced delays. At Miami, delays on departures exceeded 45 minutes.
The sequester has forced the Department of Transportation to cut $1 billion from its budget. Of that, $637,000 will come from the FAA. Employees will be required to take 11 days of unpaid leave between Sunday, April 21, and the end of September.
FAA officials have said the budget cuts left them no choice but to begin furloughing all 47,000 agency employees, including nearly 15,000 controllers. Each employee will lose one day of work every other week. That translates into fewer workers monitoring the same number of flights in the air.
"The FAA will be working with the airlines and using a comprehensive set of air traffic management tools to minimize the delay impacts of lower staffing as we move into the busy summer travel season," the agency said in a statement Sunday.
The busy summer travel season might bring the biggest headaches for air travelers: Summer weekends can rival the Thanksgiving weekend in terms of passenger traffic.
The most significant delays reported on Sunday, the first day of the furloughs, were at Los Angeles International. LAX reported that delays on arriving flights were an average of three hours and seven minutes.
Flight delays were minimal for most of the day in the rest of the country, although there were evening delays of up to an hour reported at New York-area airports.
One lawmaker thinks that in the wake of the Boston marathon bombings last week, the furloughs need to be delayed by at least 30 days.
"Particularly now, smooth and efficient functioning airports are a core national interest," Sen. Richard Blumenthal, D-Conn. said. "A delay will give Congress an opportunity to address options for avoiding the costs and inconvenience of delays and cancellations caused by furloughs."
Airlines for America, the industry trade group, took legal action against the FAA Friday, filing a motion for a 30-day stay to prevent air traffic controller furloughs. The widespread ground stops could cause estimated delays of up to four hours at major hub airports, affecting up to 6,700 flights a day and one out of every three passengers, according to the FAA.
But individual airlines aren't yet sure how their passengers will be affected.
"Unfortunately, the FAA has not yet provided specific details to the airlines, making it difficult to communicate exactly how customers will be affected," American Airlines said. "However, we will make every effort to communicate with our customers as information becomes available."
The FAA has been ordered to find a way to cut $637 million from the agency's budget, a consequence of automatic federal spending cuts that kicked in this year after Congress failed to reach a deal to reduce the national deficit.
As ABC News reported Friday, Department of Transportation Secretary Ray LaHood at a news conference warned that passengers could see "a wide range of impacts across the system," adding that "safety is not up for negotiation during the sequester" and "will not be compromised in anything that we do."