(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.
CFR 14-145.221-2014 history
2014CFR 14-145.221-2014 Aeronautics and Space. Part145:Repair stations. Section145.221:Service difficulty reports.