 The Transportation Department says it received nearly 97,000 complaints in 2023, up from about 86,000 the year before. There were so many complaints, it took until July to sort through and count them all. Complaints about the treatment of passengers with disabilities rose by more than one-fourth. Now, on the other hand, the Federal Aviation Administration says the flight cancellation rate for the first half of 2024 was just 1.4%, nearly the lowest in over a decade.