Fourth of July weekend will test airlines struggling to bounce back.

Delays and cancellations have plagued air travel, and the Fourth of July weekend may be the biggest test yet for the airline industry, which has faced scrutiny from customers, regulators and investors.

The industry has not fully recovered from the depths of the pandemic. Airlines, eager to cut costs and uncertain about the future of travel, halted hiring and doled out early retirement packages.

Now, they are scrambling, the DealBook newsletter reports. On Thursday, Robert Isom, the American Airlines chief executive, said the company had offered pilots pay raises totaling nearly 17 percent as part of the fierce talent war.

Other airline executives have weighed in on staffing challenges. “Most airlines are simply not going to be able to realize their capacity plans because there simply aren’t enough pilots, at least not for the next five-plus years,” Scott Kirby, the chief executive of United Airlines, said in April.

Airlines are pinning the blame on the F.A.A., which they say is experiencing its own staffing shortages and pandemic-related absences.

“When we look at our operations this year, versus three years ago,” Barry Biffle, the Frontier chief executive, told DealBook, “the No. 1 issue that has impacted our operations has been air traffic control.”

Airline representatives met with the F.A.A. on Thursday to discuss travel disruptions.

Regardless of who is at fault, passengers are mad. They lodged 3,173 complaints against U.S. airlines in April, according to a recent Transportation Department report, over issues like refunds, delays and baggage. That’s nearly three times as many complaints as were made a year earlier.

Investors are also unhappy as they consider other challenges, like rising fuel prices. Shares of most major U.S. airlines are down about 30 percent this year.

Senator Bernie Sanders, the Vermont independent, is asking Pete Buttigieg, the transportation secretary, to require airlines to pay fines of $15,000 per passenger for certain delays unrelated to weather. House Republicans want Mr. Buttigieg to explain the administration’s plans to address the flight mess.

Delta’s chief executive, Ed Bastian, posted a note on Thursday that seemed to be an effort to get ahead of any holiday travel pain: “If you’ve encountered delays and cancellations recently, I apologize.”