Leaving on a jet plane any time after Sunday? Better get ready to sit tight.

Department of Transportation Secretary Ray LaHood announced Thursday that flight delays at major airports could reach up to two hours and 10 minutes - and that's without accounting for weather delays or technical malfunctions.

The drawn-out delays are a side effect of sequestration, and if they come to pass as predicted, they will be one of the most highly visible effects so far. The Federal Aviation Administration begins furloughing 47,000 employees on Sunday, April 21, and passengers may start seeing delays as early as next week. Delays are expected to peak in the summer months due to travel and weather.

The DOT is required to cut $1 billion from its budget, thanks to the sequester. Of that, $637,000 will come from the FAA.

Employees will be required to take 11 days of unpaid leave between Sunday and the end of September. LaHood couldn't give more details, saying the scheduling of the furloughs within that time frame would be up to the individual airports.

LaHood and FAA chair Michael Huerta said they have spoken with the individual airlines, but they would not comment on their reactions.

LaHood said passengers would see "a wide range of impacts across the system" and added that "safety is not up for negotiation during the sequester" and as such "will not be compromised in anything we do."

Before concluding the press conference, LaHood adamantly said, "We have done everything within the sequester law to do everything possible, to do all that we can to find a billion dollars, and if we had it our way, we probably wouldn't be sitting here. It's very painful."

"This is not what we signed up for," he added. "[The sequester] is a dumb idea."

The Air Line Pilots Association, Int'l, responded to LaHood's announcement, saying the furloughs would have a "very negative impact" on all involved.

"For the airlines, it means significant cuts in capacity and major financial losses. For pilots, it could span from challenges getting to work to losing their jobs. For passengers, it could mean a lot of time waiting in airports and not making it to their destinations on time," the country's largest pilots' union wrote in a statement. "We need to work together-Congress, the administration, industry, and labor-to protect the operational integrity of the safest system in the world, or we will be forced to deal with the fiscal realities of these decisions."

Washington, D.C., where the sequester originated, skirted the list of cities that will be most heavily affected by the delays, but other major metropolitan areas weren't so lucky. The list of airports that are likely to field the most delays includes Newark, JKF, LaGuardia, Chicago O'Hare, LAX, Atlanta, Ft. Lauderdale, San Diego, Philadelphia, Charlotte, San Francisco, Chicago Midway and Miami.

LaHood predicted these longer delays at the start of the sequester, but up to now, any effects have flown under the radar.

ABC's Matt Hosford contributed to this report.