47 CFR 1.744 - Amendments.
(a) Any application not designated for hearing may be amended at any time by the filing of signed amendments in the same manner, and with the same number of copies, as was the initial application. If a petition to deny (or to designate for hearing) has been filed, the amendment shall be served on the petitioner.
(b) After any application is designated for hearing, requests to amend such application may be granted by the presiding officer upon good cause shown by petition, which petition shall be properly served upon all other parties to the proceeding.
(c) The applicant may at any time be ordered to amend his application so as to make it more definite and certain. Such order may be issued upon motion of the Commission (or the presiding officer, if the application has been designated for hearing) or upon petition of any interested person, which petition shall be properly served upon the applicant and, if the application has been designated for hearing, upon all parties to the hearing.