The advisory board shall be composed of five (5) members to be appointed by the governor. All members shall be knowledgeable and have experience in aviation; provided however, one (1) member shall have particular knowledge of commercial aviation; one (1) member shall have knowledge of general aviation; one (1) member shall have particular knowledge of back-country aviation; and one (1) member shall have particular knowledge of air freight transportation. Not more than three (3) members thereof shall at any time belong to the same political party. Provided, however, two (2) members of the advisory board shall be licensed pilots. Members shall be successful public spirited citizens of good character, well informed and interested in the construction and maintenance of aeronautical facilities. Selection and appointment shall be made solely with regard to the best interests of the various functions of the advisory board. Each member at the time of his appointment shall be a citizen and resident taxpayer of the state of Idaho, and of the members appointed to represent director districts, such member shall be a resident of the district from which he is appointed for at least three (3) years.