14 CFR 241.9 - Functional Classification
This classification is prescribed for all air carrier groups and shall include all revenues from the air transportation of traffic of all classes. It shall consist of the following subclassifications:
This subclassification shall include revenues from the transportation by air of individual passengers or cargo shipments (as opposed to charter flights) pursuant to published schedules, including extra sections and other flights performed as an integral part of published flight schedules.
This subclassification shall include revenues from the transportation by air of traffic applicable to the performance of aircraft charters, and other air transportation services not part of services performed pursuant to published flight schedules (but shall not include data applicable to flights performed as extra sections to published flight schedules, which shall be reported in the subclassification 3100 Scheduled Services).
(a) This classification is prescribed for all air carrier groups and shall include all revenues from the United States Government as direct grants or aids for providing air transportation facilities and all revenues from services which grow from and are incidental to the air transportation services performed by the air carrier.
(b) Revenues related to services of a magnitude or scope beyond an incidental adjunct to air transportation services shall not be included in this classification (see section 1-6(b)). Revenues applicable to such services shall be included in profit and loss classification 8100, Nonoperating Income and Expense-Net, and the accounting modified to conform with that of a nontransport division whether or not the service is organized as a nontransport division.