This chapter shall not apply to aircraft operated exclusively by an air carrier or a foreign air carrier, as defined in subdivisions (2) and (19) of Section 1 of Chapter 601 of the Statutes of the Seventy-fifth United States Congress, Second Session (1938), engaged in air transportation as defined in subdivision (10) of the same section while there is in force a certificate by, or a foreign air carrier permit of, the Civil Aeronautics Board of the United States, or its successor, authorizing such air carrier to engage in such transportation.