Upon receipt of any application for a certificate of approval of an airport, heliport or restricted landing area, or an original license to use or operate an airport, heliport, restricted landing area or other air navigation facility, the executive director shall send notice thereof by registered or certified mail to the chief executive officer or first selectman of the municipality or municipalities in which the proposed airport, heliport, restricted landing area or other air navigation facility is proposed to be located. If the applicant, or such municipality within fifteen days after receipt of such notice, requests a public hearing, the executive director shall set a time and place for such hearing in the municipality in which the proposed airport, heliport, restricted landing area or other air navigation facility is proposed to be situated, at which hearing interested parties shall have an opportunity to be heard. The executive director may hold a public hearing in any case where no such request is made. Notice of any such hearing shall be published by the executive director in a newspaper of general circulation in such municipality at least twice, the first publication to be at least fifteen days prior to the date of the hearing. Upon the conclusion of such hearing, the executive director shall consider all the relevant evidence and shall issue an order granting or denying such application, written notice of which shall be sent by registered or certified mail to the applicant and to the chief executive officer or the first selectman of the municipality or municipalities in which the proposed airport, heliport, restricted landing area or other air navigation facility is to be located. Orders issued pursuant to this section shall comply with the requirements of § 15-66 and shall be subject to appeal as provided in § 15-67.