Section 375.40 - Permits for commercial air operations(a)Permit required. Except for aircraft being operated under a foreign air carrier permit, an exemption, or as otherwise provided in subpart D or H of this part, foreign civil aircraft may engage in commercial air operations only if there is carried on board the aircraft a permit issued by the Department in accordance with this subpart authorizing the operations involved.(b) Aircraft are not authorized to engage in air transportation under this section. Where an operation involves the carriage of persons, property or mail for compensation or hire, the Department will determine whether particular flights for which a permit is sought will be in common carriage, and therefore in air transportation, based on all the facts and circumstances surrounding the applicant's entire operations. The burden rests upon the applicant in each instance to demonstrate by an appropriate factual showing that the contemplated operation will not constitute common carriage from, to or within the United States. In general, an applicant that holds itself out to the public, or to a particular class or segment, as willing to furnish transportation for hire is a common carrier.