This industry comprises establishments primarily engaged in providing air transportation of passengers and/or cargo over regular routes and on regular schedules. Establishments in this industry operate flights even if partially loaded. Establishments primarily engaged in providing scheduled air transportation of mail on a contract basis are included in this industry. Illustrative Examples: Air commuter carriers, scheduled Scheduled air passenger carriers Scheduled air cargo carriers (except air couriers) Scheduled helicopter passenger carriers Cross-References. Establishments primarily engaged in--