Terms as used in this chapter mean:
(1) "Air commerce," the transportation by aircraft of persons or property for hire in interstate or international transportation on regularly scheduled flights;
(2) "Aircraft," any contrivance used or designed for navigation of, or flight in the air;
(3) "Airline company," any person who undertakes directly to engage in the business of air commerce;
(4) "Flight property," all aircraft fully equipped ready for flight used in air commerce;
(5) "Flight time," hours spent by aircraft in flight on regularly scheduled flights;
(6) "Person," any individual, corporation, limited liability company, firm, copartnership, company, or association and includes any guardian, trustee, personal representative, receiver, conservator, or any person acting in any fiduciary capacity therefor;
(7) "Secretary," the secretary of revenue.