14 CFR §385.30

Petitions for review may be filed by the applicant; by persons who have availed themselves of the opportunity, if any, to participate in the matter at the staff action level; and by persons who have not had opportunity to so participate or show good and sufficient cause for not having participated: Provided, That such persons, other than the applicant, disclose a substantial interest which would be adversely affected by the respective staff action.