(1) The governing bodies having power to appropriate moneys within the municipalities in this state for the purpose of acquiring, establishing, constructing, enlarging, improving, maintaining, equipping or operating airports and other air navigation facilities under the provisions of this chapter, are hereby authorized to appropriate and cause to be raised by taxation or otherwise in such municipalities, moneys sufficient to carry out therein the provisions of this chapter.

(2) The revenues obtained from the ownership, control and operation of any such airport or other air navigation facility shall be used, first, to finance the maintenance and operating expenses thereof, and, second, to make payments of interest on and current principal requirements of any outstanding bonds or certificates issued for the acquisition or improvement thereof, and to make payment of interest on any mortgage heretofore made. Revenues in excess of the foregoing requirements may be applied to finance the extension or improvement of the airport or other air navigation facilities, and to construct, maintain, lease, and otherwise finance buildings and facilities for industrial or commercial use: PROVIDED, That such portion of the airport property to be devoted to said industrial or commercial use be first found by the governing body to be not required for airport purposes.