In proceedings handled by the Department of Transportation Office of Hearings, its functions shall attach upon notice of the institution of a formal proceeding involving a prehearing conference and/or a hearing by the Administration. [G.O. 41, 3d Rev., 29 FR 14475, Oct. 22, 1964; 29 FR 15374, Nov. 17, 1964, as amended at 63 FR 9157, Feb. 24, 1998]