(1) A tax is imposed upon aviation fuel at the rates provided in this section.
(2) Except as provided by Subsection (3), the tax on aviation fuel shall be 9 cents per gallon.
(3) Aviation fuel purchased for use by a federally certificated air carrier is subject to a tax of:
(a) 4 cents per gallon on aviation fuel purchased other than at an international airport:
(i) located within a county of the first class; and
(ii) that has a United States customs office on its premises; or
(b) 2.5 cents per gallon on aviation fuel purchased at an international airport:
(i) located within a county of the first class; and
(ii) that has a United States customs office on its premises.