Nearly 2.5 million people passed through U.S. airport security checkpoints Friday, the most since February 2020.

Another 2.2 million were screened Saturday and 2.1 million on Sunday.

Why it matters: The air travel system has been struggling with staffing shortages and other issues, making the past few days a big test for airlines, airports and the Federal Aviation Administration.

By the numbers: 26.9% of U.S.-based carriers’ arrivals were delayed Friday, per FlightAware, with an average delay of 51 minutes. Another 464 flights were canceled.