Data from all U.S. air carrier domestic and international, scheduled passenger flights. International data in system total includes U.S. carrier operations to and from the U.S. and from one foreign point to another foreign point. BTS’ Airlines and Airports available here does not include U.S. carriers’ foreign point-to-point flights.
This data is collected by the U.S. Department of Transportation, Bureau of Transportation Statistics (BTS) calculation from BTS U.S. Air Carrier Traffic Statistics reported in BTS' monthly Air Traffic Data release, available here.
U.S. Bureau of Transportation Statistics, Enplanements for U.S. Air Carrier Domestic and International, Scheduled Passenger Flights [ENPLANED11], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/ENPLANED11, October 1, 2023.