The commission, any member thereof, the director or any officer or employee of the commission designated by it, shall have the power to hold investigations, inquiries and hearings concerning matters covered by the provisions of this article and the rules, regulations and orders of the commission, and concerning accidents in aeronautics within this state. Hearings shall be open to the public and, except as provided in section twenty-two, shall be held upon such call or notice as the commission shall deem advisable. Each member of the commission, the director and every officer or employee of the commission designated by it to hold any inquiry, investigation or hearing shall have the power to administer oaths and affirmations, certify to all official acts, issue subpoenas, and order the attendance and testimony of witnesses and the production of papers, books and documents. In case of the failure of any person to comply with any subpoena or order issued under the authority of this section, the commission or its authorized representative may invoke the aid of any circuit court of this state. The court shall thereupon order such person to comply with the requirements of the subpoena order or to give evidence touching the matter in question. Failure to obey the order of the court may be punished by the court as a contempt thereof. A claim that any such testimony or evidence may tend to incriminate the person giving the same shall not excuse witness from testifying, but such witness shall not be prosecuted for any offense concerning which he is compelled hereunder to testify.
Subject to the foregoing provision, the commission may in its discretion make available to appropriate federal, state and municipal agencies information and material developed in the course of its investigations and hearings.