Airports in Europe can’t catch a break from summertime crowds and chaos — and the mess is starting to affect U.S. carriers.American Airlines told employees on Wednesday that it is pausing ticket sales on flights that depart Amsterdam Airport Schipol (AMS) from July 7 to July 31, at the airport’s request; “other airports may soon follow,” the company added.“Given the number of confirmed tickets already sold, American is no longer selling seats on our flights departing from AMS during this timeframe,” the note to employees said, which was seen by TPG and confirmed by an airline spokesperson.Want more airline-specific news? Sign up for TPG’s free new biweekly Aviation newsletterAmerican operates two flights a day from AMS: a flight to Philadelphia International Airport (PHL) and a flight to Dallas/Fort Worth International Airport (DFW). American’s move only affects those two flights; it is still selling tickets out of Amsterdam on joint venture partners such as British Airways and Aer Lingus. Tickets on American-operated flights to Amsterdam will continue to be sold as normal.A spokesperson for Delta Air Lines — which operates 17 daily departures out of Amsterdam and uses the airport as a major European gateway with partner KLM — told TPG the carrier was not making any changes to its operations there. United Airlines — which has five daily departures from AMS — did not respond to a request for comment.AMS has perhaps been the hardest-hit airport in Europe this summer; travelers have faced crushingly long lines and frequent flight disruptions amid widespread staffing shortages. Last month, KLM paused ticket sales for a weekend due to overcrowding. The following weekend, the Dutch flag carrier took a remarkable step — it did not even board passengers on some flights to AMS.Amsterdam is not alone, though.Air travel apocalypse: Every flight on my trip got disrupted; things you should knowSign 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.This week, the Lufthansa Group sent its passengers an apology letter for disruptions across its portfolio of European airlines.“The ramp-up of the complex air transport system from almost zero to now almost 90% is clearly not proceeding with the reliability, the robustness and the punctuality that we would like to offer you again,” the owners of Lufthansa, Austrian Airlines, Swiss, Brussels Airlines and Eurowings wrote. “We want to be completely honest: In the coming weeks, as passenger numbers continue to rise, be it for leisure or business travel, the situation is unlikely to improve in the short term.“The company hopes things will be better next summer, according to the letter.Giving up? Delta issues travel waiver for July 4 weekend for allAirports in the U.K. such as London Heathrow Airport (LHR) and Manchester Airport (MAN) have also been subject to large crowds and operational issues. Heathrow has faced baggage-handling backups, while Manchester has faced long security lines. Just this morning, Heathrow asked airlines to cancel 30 flights due to concerns about the airport going over capacity.While Europe is perhaps the faring the worst of all regions right now when it comes to flight disruptions, similar issues are playing out in other parts of the world.More: TPG’s guide to understanding EU261 flight compensationLate Wednesday night, Air Canada announced it would be trimming its July and August flight schedules in a “meaningful” way — roughly 154 flights per day — due to its own operational issues.“Around the world, there are recurring incidents of flight delays and airport congestion, resulting from a complex array of persistent factors impacting airlines and our partners in the aviation ecosystem,” Air Canada CEO Michael Rousseau wrote in a letter to customers.Earlier this week, Delta issued a highly unusual network-wide travel waiver for flights between July 1 and July 4, and it predicted operation issues across its network during the holiday weekend. Last week, United announced it was trimming 50 flights per day at its hub at Newark Liberty International Airport (EWR) due to congestion.If you’re caught up in this summer’s flight delays and cancelations, here’s what to do. If your flight involves Europe, here’s an explainer on EU261, and how you can be compensated in the event of a flight disruption.