Before any such taxing body shall be authorized to issue bonds as in this Act provided:
(a) The Board of Directors of the airport and landing field shall adopt plans and specifications describing the airport and landing field to be constructed or improved, the type of construction of or improvement to be made, and shall make an estimate of the cost of such construction or improvement, and shall procure approval of such plans and specifications and the estimate of the costs thereof from the Department of Transportation of this State; and(b) The Board of Directors of the airport and landing field shall transmit such plans and specifications and estimate of costs, together with the approval thereof by the Department of Transportation of this State, to the governing bodies of the respective taxing districts, with a request that such governing bodies adopt resolutions providing for the construction or improvement of such airport and landing field and for the issuance of the proper proportion of bonds by the respective corporate authorities to pay all or part of the costs thereof in the proportions set forth in the proposition adopted by the electors.