By Doyinsola Oladipo and Rajesh Kumar Singh

NEW YORK (Reuters) -The number of people traveling by air in the United States for the Fourth of July holiday is expected to surpass pre-COVID levels for the first time in four years, but recent flight disruptions raise fresh questions about airlines’ readiness to handle the summer travel rush.

In anticipation of a busy summer, U.S. airlines have taken measures like trimming schedules and beefing up staffing to prevent large-scale flight disruptions, though inclement weather in some regions presents a risk to travelers during the period.

Despite signs of slowing consumer spending, about 51 million Americans will travel 50 miles or more from home between Friday, June 30 and Tuesday, July 4, according to travel group AAA. This is about a 4% increase from 2019 levels, the current record year for July 4th travel.

The AAA estimates do not include Thursday, June 29, which the Federal Aviation Administration expects to be the busiest day of air travel during the holiday weekend.

The U.S. Transportation Security Administration said it screened 2.7 million passengers on Thursday, up 32% from 2019.

Last weekend, thunderstorms and failing equipment at an FAA facility in the Washington area created significant delays for air travelers on the U.S. East Coast.

About 43,000 flights were delayed and over 7,700 were canceled between Saturday, June 24, and Thursday, June 29, according to flight tracking service FlightAware.

United Airlines bore the brunt of the disruptions, with about 19% of its scheduled flights canceled and about 47% delayed.

The Chicago-based carrier said its operations were beginning to see improvement. While the cancellations on Thursday were fewer than those in previous days in the week, United still scrapped 18% of its flights, data from FlightAware showed.

The disruptions have left passengers fuming, with many United customers venting frustration on social media about long lines, delays in rebooking flights and misplaced luggage.

The carrier has been apologizing to customers on Twitter for delays in responding to complaints, citing high call volumes.

“It’s all-hands-on-deck as our pilots get aircraft moving, contact center teams work overtime to take care of our customers, and our airport customer service staff works tirelessly to deliver bags and board flights,” United said in a statement.

U.S. Transportation Secretary Pete Buttigieg has called the summer travel season a “stress test” for airline operations.

“Nobody can control the weather, but it is important for airlines to create enough cushion in resilience in the system,” Buttigieg told CNN.

United CEO Scott Kirby, however, has blamed the Federal Aviation Administration for making the situation worse. In a staff memo, he said over 150,000 United customers were affected last weekend because of FAA staffing issues and its impact on managing traffic.

Still, the airline has said it would be “on track” to restore operations for the holiday weekend when it expects 5 million people to fly with it. Its bookings are up about 12% from last year and have nearly rebounded to pre-pandemic levels.

American Airlines expects nearly 3 million customers from Friday, June 30, through Tuesday, July 4, across more than 26,000 scheduled flights.

Travel spending has held up nationwide, and air carriers expect strong results through 2023, which comes against a backdrop of U.S. consumer confidence rising in June to its highest level in nearly 1-1/2 years.

AAA expects 43 million people will drive to their destinations, a 4% increase from 2019 levels.

Other modes of travel still have not reached pre-pandemic levels. The travel group expects about 3 million people will travel by bus, cruise liner, or train over the long weekend, up 24% from last year but 5% lower than 2019 levels.

(Reporting by Doyinsola Oladipo in New York and by Rajesh Kumar Singh in Chicago; editing by Deepa Babington and Jonathan Oatis)

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