Taxation of international air transport profits confined to the enterprise's contracting state, including pools and related interest. Profits from the operation of aircraft in international traffic are taxable only in the enterprise's Contracting State, including profits from participation in pools, joint businesses or international operating agencies. Interest directly connected with aircraft operations is regarded as income from those operations and excluded from the separate interest provision. The operation of aircraft covers carriage of passengers, mail, livestock or goods by owners, lessees or charterers, ticket sales for others, incidental leasing and other activities directly connected with air transportation.