Thousands of US flights delayed or cancelled over July 4 weekend

About 1,300 flights into and across the US are affected on Sunday

People queue to drop bags at New York's John F Kennedy International Airport. Reuters

Airlines struggling to staff their planes have cancelled or delayed thousands of US flights over the long July 4 holiday weekend.

As of Sunday morning, with Americans gearing up for Independence Day celebrations on Monday, more than 1,297 flights within, into, or out of the US had been cancelled, and more than 11,730 were delayed, according to flight tracking service flightaware.com.

The numbers on Friday and Saturday were grim as well, with thousands more flights cancelled or delayed.

The airport chaos is prompting a record level of road travel by Americans seeking to dodge flight trouble, a travel industry group said.

For days, amid a surge in travel as summer rolls in, horror stories have abounded as travellers have been stranded at airports, unable to reach their destinations.

The airline industry was devastated in the early stages of the Covid-19 pandemic as people stayed close to home, but air travel has rebounded as health measures have eased.

Although federal Covid-19 relief spared airlines from laying off staff, tens of thousands of workers left the industry after carriers urged early retirement.

Today's industry has about 15 per cent fewer staff compared with the pre-pandemic period to handle about 90 per cent of pre-2020 passenger volume, analysts at Third Bridge consultancy estimated.

The travel chaos has drawn scrutiny from Transportation Secretary Pete Buttigieg and others in Washington.

On Saturday, Mr Buttigieg tweeted a series of tips on what to do if one's flight is cancelled, such as whether to accept travel points or miles as compensation, or demand a cash refund.

"You can often negotiate on this. That's between you and the airline," Mr Buttigieg wrote.

The travel season is at full speed, with 2,490,490 people screened at airport checkpoints nationwide on Friday, the most since February 2020, just before the Covid shutdown in the US, the Transportation Security Administration said.

"We are back to pre-pandemic checkpoint volume," the TSA tweeted.

Delta pilots walked along informational picket lines at several airports on Thursday to demand a new contract and complain of overwork, among other issues.

"Quite frankly, it's irresponsible scheduling, over scheduling. Coming out of the pandemic, we're scheduling more flights than we have people to fly them," Delta pilots association union leader Jason Ambrosi told CNN on Saturday.

- AFP contributed to this report

Fireworks on the boardwalk at New York's historic Coney Island. Photo: Bob Jagendorf

Face-painting is often a US holiday tradition. Photo: US National Archives

The National Archives celebrates Independence Day with musical performances, a dramatic reading of the Declaration of Independence, and history-related family activities, this time in 2019 in Washington DC. Nara Photo by Jeffrey Reed.

Washington Nationals Racing Presidents stop at the National Archives to shoot a new fourth-inning race introduction video, where they were met by US Archivist David Ferriero.

Visitors read the US Constitution on display at the National Archives in Washington.

The skyrockets' red glare lights up the Washington Monument. Photo: Joseph Gruber

The National Archives celebrates Independence Day with musical performances, a dramatic reading of the Declaration of Independence, and history-related family activities on July 4, 2019, in Washington DC. NARA Photo by Jeffrey Reed.

A man and his patriotic dog show their civic pride. Photo Faith Goble

Role players recreate a scene from 1776 for an audience outside Washington's National Archives. Photo: US National Archives

Disneyland's Space Mountain and an epic fireworks display. Photo: Don Sullivan

The National Archives celebrates Independence Day with musical performances, a dramatic reading of the Declaration of Independence, and history-related family activities on July 4, 2019 in Washington DC. NARA Photo by Ted Chaffman.

Costumed role players participate in Washington's Independence Day tradition. Photo: US National Archives

Independence Day in the US is celebrated from coast to coast. Photo: US Army

Flag-bearing Fourth of July revellers rumble through the streets of middle America. Photo: Ken Mattison

Macy's department store hosts one of the nation's largest displays of fireworks on New York's East River. Photo: Dan Nguyen

A four-legged American shows its colours. Photo: Randy Robertson

Parades throughout the streets of America are a Fourth of July tradition and give classic car owners a chance to strut their stuff. Photo: Robert Couse-Baker

Residents of Berkeley, California, enjoy an evening of pyrotechnics. Photo: Daniel Parks

A giant bald eagle balloon makes its way through Washington and past the National Archives. Photo: US National Archives

The National Archives hosts an annual Independence Day celebration with musical performances, a dramatic reading of the Declaration of Independence, and history-related family activities. Photo: US National Archives

An air dancer by the National Archives on the Fourth of July in Washington. Photo: US National Archives

The National Mall, with Washington monuments and the US Capitol in the background, forms a beautiful and patriotic backdrop to America's Independence Day celebrations. Photo: Carol Highsmith