14 CFR § 145.221 - Service difficulty reports.
(a) A certificated repair station must report to the FAA within 96 hours after it discovers any serious failure, malfunction, or defect of an article. The report must be in a format acceptable to the FAA.
(b) The report required under paragraph (a) of this section must include as much of the following information as is available:
(1) Aircraft registration number;
(2) Type, make, and model of the article;
(3) Date of the discovery of the failure, malfunction, or defect;
(4) Nature of the failure, malfunction, or defect;
(5) Time since last overhaul, if applicable;
(6) Apparent cause of the failure, malfunction, or defect; and
(7) Other pertinent information that is necessary for more complete identification, determination of seriousness, or corrective action.
(c) The holder of a repair station certificate that is also the holder of a part 121, 125, or 135 certificate; type certificate (including a supplemental type certificate); parts manufacturer approval; or technical standard order authorization, or that is the licensee of a type certificate holder, does not need to report a failure, malfunction, or defect under this section if the failure, malfunction, or defect has been reported under parts 21, 121, 125, or 135 of this chapter.
(d) A certificated repair station may submit a service difficulty report for the following:
(1) A part 121 certificate holder, provided the report meets the requirements of part 121 of this chapter, as appropriate.
(2) A part 125 certificate holder, provided the report meets the requirements of part 125 of this chapter, as appropriate.
(3) A part 135 certificate holder, provided the report meets the requirements of part 135 of the chapter, as appropriate.
(e) A certificated repair station authorized to report a failure, malfunction, or defect under paragraph (d) of this section must not report the same failure, malfunction, or defect under paragraph (a) of this section. A copy of the report submitted under paragraph (d) of this section must be forwarded to the certificate holder.