14 CFR §217.6

1. (a)If circumstances prevent the filing of a Schedule T-100(f) report on or before the due date prescribed in section 22 of part 241 of this chapter and appendix A of this part, a request for an extension must be filed with the Director, Office of Airline Information.
2. (b)The extension request must be received at the address provided in § 217.10 at least 3 days in advance of the due date, and must set forth reasons to justify granting an extension, and the date when the report can be filed. If a request is denied, the air carrier must submit the required report within 5 days of its receipt of the denial of extension.