47 CFR §1.241

1. (a)Hearing proceedings will be conducted by a presiding officer. The designated presiding officer will be identified in the order designating a matter for hearing. Only the Commission, one or more commissioners, or an administrative law judge designated pursuant to 5 U.S.C. 3105 may be designated as a presiding officer. Unless otherwise stated, the term presiding officer will include the Commission when the Commission designates itself to preside over a hearing proceeding.
2. (b)If a presiding officer becomes unavailable during the course of a hearing proceeding, another presiding officer will be designated.