Major airports serving the largest U.S. cities were bracing for chaos as a government shutdown threatened to cancel thousands of flights each day, just as the holiday travel season kicked off.

The Federal Aviation Administration (FAA) announced that 40 airports nationwide would feel the impact starting Friday, as a shortage of air traffic controllers due to the shutdown created what experts described as a logistical nightmare.

These reductions could disrupt thousands of flights across the country, considering the FAA manages over 44,000 flights every day.

“I won’t sugarcoat it; if these cuts proceed, the next few days will be an absolute mess,” stated Henry Harteveldt, an airline industry analyst.

On Wednesday, Transportation Secretary Sean Duffy and FAA Administrator Bryan Bedford revealed a 10 percent slowdown plan, with Bedford acknowledging that the aviation sector might be venturing into unprecedented challenges.

‘We’re in new territory in terms of government shutdowns,’ Bedford said. ‘I’m not aware in my 35-year history in the aviation market where we’ve had a situation where we’re taking these kinds of measures.’ 

President Trump told Republican senators during a breakfast meeting at the White House Tuesday that ‘we must get the government back open soon and really immediately.’ 

At the same meeting, Trump blamed major GOP’s losses in an off-year election on the shutdown – now the longest stalemate in US history.

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The flight shortages will affect the three major airports in the NYC area – JFK, LaGuardia and Newark Liberty – as well as airports in Chicago, Los Angeles, Philadelphia and Washington DC. 

The FAA said it was making the extraordinary cutback to maintain travel safety as air traffic controllers exhibit signs of strain during the shutdown.

Air traffic controllers have been working unpaid since the shutdown began October 1, and most have been on duty six days a week while putting in mandatory overtime. 

With some calling out of work due to frustration, taking second jobs or not having money for child care or gas, staffing shortages during some shifts have led to flight delays at a number of US airports.

Bedford, citing increased staffing pressures and voluntary safety reports from pilots indicating growing fatigue among air traffic controllers, said he and Duffy did not want to wait until the situation reached a crisis point.

‘We’re not going to wait for a safety problem to truly manifest itself when the early indicators are telling us we can take action today to prevent things from deteriorating,’ Bedford said. 

‘The system is extremely safe today and will be extremely safe tomorrow. If the pressures continue to build even after we take these measures, we´ll come back and take additional measures.’

United, Southwest and American all said they will try to minimize the impact on consumers as they cut their schedules to comply with the order.

Calls to the customer service hotlines at United and American were answered within a few minutes Wednesday afternoon, suggesting anxious passengers were not swamping the airlines with questions about the status of their upcoming flights. 

United said on social media that they are working to update schedules so travelers can known with several days’ advance and that all customers are eligible for refunds, even if their flight is not impacted. 

In a letter to employees, United CEO Scott Kirby promised to focus the cuts on regional routes and flights that don’t travel between hubs. 

He said the airline will try to reschedule customers when possible and will also offer refunds to anyone who doesn’t want to fly during this time, even if their flight isn’t canceled.

‘United´s long-haul international flying and our hub-to-hub flying will not be impacted by this schedule reduction direction from the FAA,’ Kirby said. 

‘That´s important to maintain the integrity of our network, give impacted customers as many options as possible to resume their trip, and sustain our crew pairing systems.’

Harteveldt said he thinks the government may have bungled this announcement by not meeting with airlines first and giving them more time to adjust schedules made months in advance.

‘To tell airlines you´ve got 48 hours to rebuild your schedules at 90% of what you´ve got isn´t much time, and it´s going to result in a lot of chaos,’ said Harteveldt, who was waiting to hear if his own flight from San Francisco to Dallas on Saturday would be canceled. 

He added that the Trump administration may be using aviation safety ‘to force the two sides in Washington back to the negotiating table to resolve the shutdown.’ 

AAA spokesperson Aixa Diaz advised travelers to watch for flight updates on the airline’s app and airport social media accounts. 

She also recommended allowing plenty of time at the airport before a scheduled flight.

‘It´s frustrating for travelers, because there´s not much you can do. At the end of the day, you either fly or you don´t,’ she said.

The cuts could represent as many as 1,800 flights and upward of 268,000 seats combined, according to an estimate by aviation analytics firm Cirium. 

For example, O´Hare International Airport in Chicago could see 121 of its 1,212 flights currently scheduled for Friday cut if the FAA distributes the reductions equally among impacted airports, Cirium said.

The FAA regularly slows down or stops flights from taking off toward an airport for a number of reasons, including weather conditions, equipment failures and technical problems. 

Staffing shortages also may lead to slowed or halted departures if there aren’t enough controllers and another facility can’t absorb some of the work load.

Last weekend saw some of the worst staffing shortages of the shutdown, which became the longest on record early Wednesday. 

From Friday to Sunday evening, at least 39 different air traffic control facilities announced there was some potential for limited staffing, according to an Associated Press analysis of operations plans sent through the Air Traffic Control System Command Center system. 

The figure, which is likely an undercount, is well above the average for weekends before the shutdown

During weekend periods from Jan. 1 to Sept. 30, the average number of airport towers, regional centers overseeing multiple airports and facilities monitoring traffic at higher altitudes that announced the potential for staffing issues was 8.3. 

But during the five weekend periods since the shutdown began on Oct. 1, the average more than tripled to 26.2 facilities.

Major airlines, aviation unions and the wider travel industry have urged Congress to end the shutdown.

To manage the heavy traffic with fewer controllers, the FAA has implemented a major airspace flow program, a system that controls and spaces out flights when air traffic capacity is limited. 

The program affects all flights in the airspace above much of the US, from the ground up to 60,000 feet, meaning both arrivals and departures will be impacted.

The FAA said that roughly 13,000 air traffic controllers and 50,000 TSA agents have been working without pay for weeks.

Before the shutdown, the agency was already grappling with a perpetual shortage of about 3,000 air traffic controllers.

Wednesday’s announcement came on the heels of Duffy warning a day earlier that there could be chaos in the skies next week if the shutdown drags on long enough for air traffic controllers to miss their second full paychecks next Tuesday.

Duffy said the FAA wanted to take a proactive approach instead of reacting after a disaster. 

He pointed to all the questions that arose after the deadly midair collision in January between a commercial jet and a military helicopter near Ronald Reagan Washington National Airport about why FAA didn’t recognize the risks and act sooner.

‘We learned from that. And so now we look at data, and before it would become an issue, we try to assess the pressure and try to make moves before there could be adverse consequences,’ Duffy said. ‘And that´s what´s happening here today.’

Duffy also warned on Tuesday that if the federal government shutdown continues another week, it could lead to ‘mass chaos’ and could force him to close some of the national airspace to air traffic, a drastic move that could upend American aviation.

‘If you bring us to a week from today, Democrats, you will see mass chaos, you will see mass flight delays,’ Duffy said at a press conference.

‘You’ll see mass cancellations, and you may see us close certain parts of the airspace, because we just cannot manage it. ‘We will restrict the airspace when we feel it’s unsafe.’

With the standoff in Congress over health care spending now the longest in history at day 36, Trump’s Republicans and the opposition Democrats are facing increasing pressure to end a crisis that has crippled public services.

Airlines have repeatedly urged an end ​to the shutdown, citing aviation safety risks.

Trump admitted the government shutdown contributed to Tuesday night’s election losses for Republicans. 

While the president said he didn’t expect his party to come out on top, he realizes the ongoing shutdown – now the longest in US history – could have hurt Republican candidates’ chances even more. 

‘I think if you read the pollsters, the shutdown was a big factor – negative for the Republicans,’ the president added.

Shares of major airlines,‌ including United Airlines and American Airlines, were down about one percent in extended trading.

An airline industry group estimated that over 3.2 million passengers have been affected by flight delays or cancellations due to rising air traffic controller absences since the shutdown began ⁠on October 1. 

Airlines have been raising ​concerns with lawmakers about the impact on ​operations.

While the shutdown has not significantly affected business, airlines have warned that bookings could drop if it drags ‍on. More ⁠than 2,100 flights were delayed on Wednesday.