Pursuant to the stated intent of section 305.233, any city, town or county individually or jointly with any other city, town or county planning to build, develop, improve or expand a public airport shall channel such request through the state department of transportation. Provided further, that land airports serving Civil Aeronautics Board certificated air carriers and so certificated under CFR14 Part 139 are exempt from the requirements of channelization supra; but may request the state department of transportation to provide such service. The department of transportation is authorized to cooperate with the government of the United States and any agency or department thereof, in the acquisition, construction, improvement, maintenance and operation of airports and other navigation facilities in this state and to comply with the provisions of the laws of the United States and any regulations made thereunder for the expenditure of federal money upon such airports and other navigation facilities.