47 CFR § 18.117 - Report of interference investigation.
(a) An interim report on investigations and corrective measures taken pursuant to § 18.115 of this part shall be filed with the Regional Director of the local FCC office within 30 days of notification of harmful interference. The final report shall be filed with the Regional Director within 60 days of notification.
(b) The date for filing the final report may be extended by the Regional Director when additional time is required to put into effect the corrective measures or to complete the investigation. The request for extension of time shall be accompanied by a progress report showing what has been accomplished to date.