As Americans take to the skies while celebrating the nation’s birthday this weekend, Delta Air Lines has a message for passengers before boarding one of their red, white and blue planes: be patient.The Atlanta-based carrier has taken the remarkable step of acknowledging that it expects “operational challenges” days before the Fourth of July holiday weekend starts and on Tuesday issued a travel waiver for flights between July 1 and July 4.Want more airline-specific news? Sign up for TPG’s free new biweekly Aviation newsletter.“Delta people are working around the clock to rebuild Delta’s operation while making it as resilient as possible to minimize the ripple effect of disruptions,” the airline said in a blog post. “Even so, some operational challenges are expected this holiday weekend. This unique waiver is being issued to give Delta customers greater flexibility to plan around busy travel times, weather forecasts and other variables without worrying about a potential cost to do so.“Delta’s operation has struggled in recent weeks, particularly on weekends. Last weekend, the airline canceled hundreds of flights, by far the most of any U.S. carrier. The move underscores the broader problems the industry has had as a whole in ramping up operations since the depths of the pandemic.This weekend, Delta expects to break pandemic-era passenger records. In the run-up to the holiday weekend, new pandemic-era records have been set at Transportation Security Administration checkpoints.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.“Delta is expected to carry customer volumes from Friday, July 1, through Monday, July 4, not seen since before the pandemic as people yearn to connect with the world,” the airline said in the blog post. Delta is scheduled to operate about 11,000 flights between July 1 and July 4, according to Cirium schedule data. When Delta’s regional airline partners are included, that number jumps to just over 17,000 flights.More: Why do flight cancellations and delays keep happening?While Delta has been facing the most operational difficulties, it is far from alone. Other airlines have canceled and delayed significant numbers of flights as a slew of factors converge to cause problems during a period of very high travel demand.Airlines and the Federal Aviation Administration, which runs the nation’s air traffic control system, have traded blame for the root cause of the problems. The airlines have accused the FAA of not properly staffing ATC facilities, while the FAA says the airlines are overscheduling flights relative to the staff — especially pilots — that are available.“The majority of cancelations, and the majority of delays have nothing to do with air traffic control staffing,” Transportation Secretary Pete Buttigieg told “NBC Nightly News” on Tuesday. “But, when there is an issue, we’re working that issue,” a reference to an ATC facility in Florida that has faced staffing and other issues that airlines and the FAA held a meeting about in May.More: Your flight is canceled or delayed – here’s what you should do nextIf you’re flying Delta — or any other airline — this weekend, it might be best to try and change to the first flight of the day, if possible, as those flights are the least likely to be delayed or canceled. Also, if you’re traveling ahead of a cruise or an important gathering, try and leave some additional buffer between your flight and wherever you’re headed.