14 CFR 241.19-4 - Service classes.
The statistical classifications are designed to reflect the operating elements attributable to each distinctive class of service offered. The operating elements shall be grouped in accordance with their inherent characteristics as follows:
(a) Scheduled services. Scheduled services shall include traffic and capacity elements applicable to air transportation provided pursuant to published schedules and extra sections to scheduled flights. Scheduled Passenger/Cargo (Service Class F) is a composite of first class, coach, and mixed passenger/cargo service. The following classifications shall be reported, as applicable:
(b) Nonscheduled services. Nonscheduled services shall include all traffic and capacity elements applicable to the performance of nonscheduled aircraft charters, and other air transportation services not constituting an integral part of services performed pursuant to published flight schedules. The following classifications shall be reported, as applicable:
(c) All Services. This classification shall reflect, for the applicable elements, the aggregate amounts for all services performed by the operating entity: