This database includes departures, total passengers, freight and mail by and airline and departing airport. Data are compiled by origin airports and air carriers. Airport codes and air carrier codes are included in returned data. Some BTS updates contain multiple records for a small number of idential airport and airline combinations. In these cases, records are combined to create an airport total. Some BTS updates also contain a small number of incomplete records. These are excluded from the data.

Airline names that end with a number in parenthesis, e.g., Pan American World Airways (1), indicates that the same airline name has been used by more than one airline. This is common when an airline files for bankruptcy and then reforms as a new entity.