{"id":"F2006B04436","name":"AD/BELL 206/121 - Tail Rotor Blade Assembly","slug":"ad-bell-206-121-tail-rotor-blade-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44273,"registerId":"commonwealth-F2006B04436-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 206/121 - Tail Rotor Blade Assembly","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters\n\nAD/BELL206/121 Tail Rotor Blade Assembly 9/90\n\nTX\n\nApplicability: All models.\n\nRequirement: 1. Determine the part number and serial number of the tail rotor blade assembly installed on the helicopter.\n\n2. If the tail rotor blade assembly installed is P/N 206-016-201-113 or P/N 206-016- 201-127 and is identified with any serial number listed below, remove and replace the blade assembly.\n\n| Serial Numbers: | T-41361  | T-41627 | T-41725 |\n| --------------- | -------- | ------- | ------- |\n|                 | T-41737  | T-42088 | T-42127 |\n|                 | T-42157  | T-42307 | T-42311 |\n|                 | T-42316  | T-42494 | T-42496 |\n|                 | T-42497  | T-42502 | T-42523 |\n|                 | T-42534  | T-43276 | T-44089 |\n|                 | T-44120  | T-44157 | T-44174 |\n|                 | T -44222 | T-44300 | T-44638 |\n\nNote: FAA Emergency AD 90-13-01 refers.\n\nCompliance: Prior to further flight after 26 June 1990.\n\nBackground: The FAA has listed the blades above as being life expired. They may have been represented as airworthy newly overhauled blades using falsified documentation.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD enforces the original safety objective: it applies to all models and requires removal/replacement of the specified P/Ns and listed serial numbers before further flight. It does not broaden applicability beyond the listed parts/serials or change the stated compliance deadline."},"complexity_factors":["Immediate compliance deadline: \"Prior to further flight after 26 June 1990\" (Compliance) increases operational urgency","Identification task: must verify both part numbers and specific serial numbers against a multi‑entry list (Requirement)","Enumerated list of specific serial numbers requires precise record and physical checks","Potential need to investigate maintenance/overhaul records because of reported falsified documentation (Background)","Replacement creates direct cost and downtime for operators and coordination with maintenance/parts suppliers","Reference to FAA Emergency AD 90-13-01 introduces interjurisdictional reliance on foreign authority (Note)"],"plain_english_summary":"This AD requires owners/operators of Bell/Agusta‑Bell 206 helicopters to check the tail‑rotor blade assembly part and serial numbers and to remove and replace any assembly with P/N 206-016-201-113 or P/N 206-016-201-127 if its serial number appears on the listed set (Requirement). \n\nCompliance is mandatory prior to further flight after 26 June 1990; operators pay for replacement and face grounding/downtime. The AD follows FAA advice that these blades are life‑expired and may have been represented as overhauled using falsified documentation (Compliance; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect and fraud issue. It has not expanded beyond its original purpose of grounding specific defective tail rotor blades."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 main requirements with clear conditional logic (IF part number matches AND serial number matches, THEN remove)","No defined terms section or interpretation provisions","No cross-references to other legislation (only a note referencing the related FAA directive)","Simple tabular data for serial numbers (24 items)","Single compliance date with no exceptions or alternative methods"],"plain_english_summary":"This AD requires immediate removal and replacement, before further flight, of certain life‑expired Bell 206 tail rotor blades that were fraudulently sold with forged “overhauled” paperwork. It affects Bell/Agusta Bell 206 operators who have blades with part numbers 206‑016‑201‑113 or 206‑016‑201‑127 and any of 24 specified serial numbers. The directive is urgent because blade failure can cause catastrophic loss of control; the FAA and Australian authorities have ordered the action."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly","history":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly/history","analysis":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly/analysis","conflicts":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly/conflicts","importantCases":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly/important-cases","documents":"/api/acts/ad-bell-206-121-tail-rotor-blade-assembly/documents"}}