The investigative hearing officer, upon designation by the NTSB Chairman or a Board Member designated by the Chairman, shall have the following powers:

(a) To give notice concerning the time and place of investigative hearing;

(b) To administer oaths and affirmations to witnesses; and

(c) To issue subpoenas requiring the attendance and testimony of witnesses and production of documents. The investigative hearing officer may, in consultation with the chairman of the board of inquiry and the NTSB Managing Director, add witnesses until the time of the prehearing conference.