14 C.F.R. § 11.47
Yes, if FAA grants your request for more time to file comments, we grant all persons the same amount of time. We will notify the public of the extension by a document in the Federal Register. If FAA denies your request, we will notify you of the denial. To ask for more time, you must file a written or electronic request for extension at least 10 days before the end of the comment period. Your letter or message must—