The recent closure of the U.S. Department of Homeland Security, which commenced early Saturday, affects the agency tasked with screening passengers and luggage at airports nationwide. This development has rekindled memories of a previous 43-day government shutdown, notorious for causing unprecedented flight cancellations and significant delays.

During this period, Transportation Security Administration (TSA) officers are anticipated to continue working without pay as legislative deadlock persists over the funding of Homeland Security. While TSA personnel remained on duty during the record-setting shutdown that concluded on November 12, aviation analysts suggest that this scenario may unfold differently.

Despite this, prominent trade organizations representing the U.S. travel sector and leading airlines have issued warnings. They caution that prolonged lapses in DHS funding could result in increasingly congested security lines at commercial airports across the country.

For those concerned about the current shutdown and seeking to navigate its challenges, here’s what you need to know and how to prepare effectively.

What sets this shutdown apart?

While funding for Homeland Security ceased at the stroke of midnight, the rest of the federal government remains financed until September 30. Consequently, air traffic controllers employed by the Federal Aviation Administration (FAA) will continue to receive their salaries, thereby diminishing the likelihood of widespread flight disruptions.

According to the department’s contingency plan, about 95% of TSA workers are deemed essential personnel and required to keep working. Democrats in the House and Senate say Homeland Security won’t get funded until new restrictions are placed on federal immigration operations.

During past shutdowns, disruptions to air travel tended to build over time, not overnight. About a month into last year’s shutdown, for example, TSA temporarily closed two checkpoints at Philadelphia International Airport. That same day, the government took the extraordinary step of ordering all commercial airlines to reduce their domestic flight schedules.

John Rose, chief risk officer for global travel management company Altour, said strains could surface at airports more quickly this time because the TSA workforce also will be remembering the last shutdown.

“It’s still fresh in their minds and potentially their pocketbooks,” Rose said.

What is the impact on travelers?

It’s hard to predict whether, when or where security screening snags might pop up. Even a handful of unscheduled TSA absences could quickly lead to longer wait times at smaller airports, for example, if there’s just a single security checkpoint.

That’s why travelers should plan to arrive early and allow extra time to get through security.

“I tell people to do this even in good times,” Rose said.

Experts say flight delays also are a possibility even though air traffic controllers are not affected by the DHS shutdown.

Airlines might decide to delay departures in some cases to wait for passengers to clear screening, said Rich Davis, senior security advisor at risk mitigation company International SOS. Shortages of TSA officers also could slow the screening of checked luggage behind the scenes.

What travelers can do to prepare

Most airports display security line wait times on their websites, but don’t wait until the day of a flight to check them, Rose advised.

“You may look online and it says two-and-a-half hours,” he said. “Now it’s two-and-a-half hours before your flight and you haven’t left for the airport yet.”

Passengers should also pay close attention while packing since prohibited items are likely to prolong the screening process. For carry-on bags, avoid bringing full-size shampoo or other liquids, large gels or aerosols and items like pocketknives in carry-on bags.

TSA has a full list on its website of what is and isn’t allowed in carry-on and checked luggage.

At the airport, Rose said, remember to “practice patience and empathy.”

“Not only are they not getting paid,” he said of TSA agents, “they’re probably working with reduced staff and dealing with angry travelers.”

Will the shutdown drag on?

The White House has been negotiating with Democratic lawmakers, but the two sides failed to reach a deal by the end of the week before senators and members of Congress were set to leave Washington for a 10-day break.

Lawmakers in both chambers were on notice, however, to return if a deal to end the shutdown is struck.

Democrats have said they won’t help approve more funding for Homeland Security until new restrictions are placed on federal immigration operations after the fatal shooting of Alex Pretti and Renee Good in Minneapolis last month.

In a joint statement, U.S. Travel, Airlines for America and the American Hotel & Lodging Association warned that the shutdown threatens to disrupt air travel as the busy spring break travel season approaches.

“Travelers and the U.S. economy cannot afford to have essential TSA personnel working without pay, which increases the risk of unscheduled absences and call outs, and ultimately can lead to higher wait times and missed or delayed flights,” the statement said.