Ind. Code § 8-21-9-29
The department may fix, review, revise, charge and collect fees, tolls, rentals and other charges for the use of the airport, airport facility, airport facilities and lands under the jurisdiction or control of the authority or services rendered by the department, and contract with any person, partnership, association, limited liability company, or corporation desiring the use of any airport facility or airport facilities and appurtenances for any proper purpose, and fix the terms, conditions, rentals, and rates of charges for such use. Such fees, tolls, rentals and other charges shall be reasonably related to the cost of operation, maintenance and repair of the particular airport facility or airport facilities for which the fees, tolls, rentals and other charges are fixed, including a proper allocation of the administrative expenses of the department and in case revenue bonds are issued to finance such airport facility or airport facilities, the fees, tolls, rentals and other charges relating to that airport facility or airport facilities shall be established in an amount sufficient to pay the interest on and principal of the bonds in accordance with their terms, and also sufficient to establish and maintain reserves created for all such purposes and for depreciation purposes. The fixing and collection of such fees, tolls, rentals and other charges and the expenditure of the revenues derived therefrom shall not be subject to the supervision or regulation by any other officer, commission, board, bureau or agency of the state. After such bonds have been duly paid and discharged and all obligations under any trust agreement securing the same have been performed or satisfied, any remaining surplus net revenues and all surplus net revenues thereafter derived from the operation of such airport or airports shall be paid into a sinking fund to be created by the department and used only for the purpose of improving and maintaining airport facilities under the jurisdiction of the department.
IC 8-21-9-29