The summer airline issues are here: what to expect when traveling this weekend.

A days-long disruption to flights to and from the Greater New York area has raised concerns about how prepared airlines are for the upcoming July 4 holiday, a weekend forecast for a record number of air travelers.

It is estimated that more than 4 million Americans will fly this holiday season the AAA, the group of car owners, up about 11 percent from last year and about 6 percent from the record set in 2019. The busiest day before the holiday, with 52,564 flights, will be on Thursday, the Federal Aviation Administration said.

But as travelers prepared for a busy holiday weekend, airlines tried to shift the blame onto the FAA, which directs the country’s air traffic control, for at least some of the thousands of flight cancellations and tens of thousands of flight delays across the country this week.

Here’s what travelers should know.

What is the situation like at airports in the northeast?

Travel at New York airports, particularly Newark, has been disrupted since the weekend, with many travelers reporting lengthy flight delays and difficulty rebooking canceled flights. In some cases, passengers reported sleeping in airports and waiting in lines or on the phone for hours to reach customer service.

One passenger said on Twitter that their connecting flight, operated by United Airlines and departing Newark Airport over the weekend, was delayed by approximately 15 hours after they “disembarked” the plane after midnight. Their family slept on beds in the terminal.

Thunderstorms along the East Coast piled up in “the perfect spot” to close off busy markets in New York and Florida, Chris Citrola, an FAA spokesperson, said. said in a video posted online.

“What’s happening is a domino effect of problems,” he said. “We have crews that can’t get where they need to be, we can’t get crews where they need to go and that’s starting to lead to a lot of problems at the airport itself.”

Which airlines are most affected? Who’s to blame?

Of the approximately 4,500 flights canceled nationwide on Monday and Tuesday, more than 30 percent were operated by United, according to FlightAware, a flight tracking company. Other airlines reporting significant cancellations included JetBlue Airways, Delta Air Lines subsidiary Endeavor Air and Republic Airways, which flies for Delta, United and American Airlines.

By mid-afternoon Wednesday, United, which maintains a hub at Newark Liberty International Airport, had canceled about 15 percent of the nationwide flights it had scheduled for the day, according to FlightAware. Endeavor had canceled about 12 percent of its flights, while JetBlue had canceled about 9 percent and Republic had canceled about 8 percent.

United and JetBlue blame the problems on the weather, as well as the FAA

In a statement Wednesday, United said staff shortages in air travel over the weekend contributed to “a difficult work environment”. This blame echoes what the CEO, Scott Kirby, told staff in a memo earlier this week, saying that “the FAA flat out let us down this weekend.” JetBlue also said in a statement it had struggled to keep up with its flight schedule after air traffic control restricted travel to and from New York airports for all airlines.

What’s really going on with FAA personnel?

The FAA said Monday or Tuesday it had no personnel issues with air traffic control along the East Coast. In a statement, the agency said it “will always work with anyone who is seriously willing to join us in solving a problem.”

Yet air traffic control has long been understaffed, and controllers at many facilities often work six days a week to remedy those shortcomings.

In a report published last weekthe Department of Transportation found that most of the 26 critical air traffic control facilities it identified were understaffed by 15 percent or more as of March 2022. One such facility, New York Terminal Radar Approach Control, which oversees some of the most complex and challenging airspace, employed only 54 percent of its target number of controllers.

The report said the problem has been going on for years, something United’s Mr Kirby also noted on Monday.

“It is not the fault of the current FAA leadership that they are in this seriously understaffed position — it has been building for a long time before they were in charge,” he said in his memo.

The FAA has also had staffing problems at the top. The last permanent director stepped down in March 2022 and the agency is currently led by its second temporary director.

What recourse do passengers with delayed or canceled flights have?

Most US airlines offer passengers compensation when a flight delay or cancellation is caused by a factor within the airline’s control, such as maintenance issues or understaffing. Bad weather and FAA personnel are generally ineligible.

But in cases where the airline has defaulted, major carriers will rebook passengers to the same airline at no extra cost and provide meals or meal vouchers when passengers have to wait three hours or more.

To navigate potential disruptions, travelers should download and check airline apps, consider purchasing travel insurance — which usually covers flight delays — and transition to morning departures if possible.

In the event of massive delays or cancellations, there will likely be long wait times for customer service representatives. Instead, travelers can call an airline’s overseas hotline, which usually receives a fraction of callers, says Scott Keyes, the founder of Going coma website with travel offers.

Can this holiday weekend be repeated last summer?

“It’s going to be a very hectic weekend and one of potential disruptions,” said Mike Arnot, a spokesman for the aeronautical analytics firm Cirium, noting that punishing heat in the south and smoky skies from Canadian wildfires can also cause delays.

But Going.com’s Mr. Keyes said he was optimistic it would be this summer better than last year, which he called a ‘debacle’.

He’s not the only one to use that term. From June to August last year, more than 22 percent of all flights were delayed and about 2 percent of flights were cancelled, BTS data shows.

To prevent a recurrence and ease pressure on air traffic control, the FAA has relaxed regulations at some airports to encourage airlines to operate fewer flights with larger aircraft. It also opened 169 new routes to ease congestion. Airlines hired more staff, opted to use bigger planes and began to pay closer attention to early signs of trouble.

These steps can work. Of more than 100,000 flights scheduled for Memorial Day weekend this year, less than 1 percent were canceled, according to FlightAware.