Section 28.28 - Substitution(a) If a petitioner dies or is otherwise unable to pursue the petition, the action may be completed upon substitution of a proper party.(b) A motion for substitution shall be filed by the proper party within 90 days after the death of the petitioner or other disabling event.58 FR 61992, Nov. 23, 1993, as amended at 68 FR 69301 , Dec. 12, 2003