(a) The department may loan or grant money to a state agency with a governing board authorized to operate an airport or to a governmental entity in this state to establish, construct, reconstruct, enlarge, or repair an airport, airstrip, or air navigational facility if:
(1) the money has been appropriated to the department for that purpose; and
(2) providing the money will:
(A) best serve the public interest; and
(B) best discharge the governmental aeronautics function of the state or its political subdivisions.
(b) A loan or grant under this subchapter must be made under a contract.