{"id":"F2006B02470","name":"AD/AS 355/13 Amdt 1 - Horizontal Stabilizer - Inspection and Retirement","slug":"ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41726,"registerId":"commonwealth-F2006B02470-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AS 355/13 Amdt 1 - Horizontal Stabilizer - Inspection and Retirement","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)  \nEurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\nAD/AS 355/13\n\nAmdt 1\n\n  \n\nHorizontal Stabilizer \\- Inspection and Retirement\n\n  \n5/84\n\nApplicability: All models AS 355 fitted with horizontal stabilizer P/N 355A13.0520.01.01\n\nDocument: 1. Inspect the horizontal stabilizer in accordance with Aerospatiale Telex Service Bulletin 05.10A.\n\n2. Retire the horizontal stabilizer in accordance with Aerospatiale Service Bulletin 01.01.\n\nNote: These requirements do not apply to helicopters fitted with reinforced horizontal stabilizer P/N 315A13.0520.02.01.\n\nCompliance: For Para. 1: as detailed in requirement document.\n\nFor Para. 2: For horizontal stabilizers with more than 600 hours in service, retire within 100 hours of operation after 30th April 1984. For horizontal Stabilizers with less than 600 hours in service, retire at or before 700 hours in service.\n\nBackground: Several failures of horizontal stabilizers have occurred on overseas helicopters. Elongation of the attachment bolt holes initiates fatigue cracks. This amendment introduces the life limitation of SB 01.10. Bureau Veritas AD 84-17-21(B) also refers.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical failure mode in a specific helicopter model. The amendment (Amdt 1) introduces a life limitation, which is consistent with the original purpose of preventing stabilizer failures. No scope creep detected."},"complexity_factors":["Very short document (under 300 words)","Only 2 substantive requirements (inspect and retire)","Single exemption clearly stated in a Note","Simple conditional logic based on flight hours (600-hour threshold)","No defined terms section — uses plain part numbers and references to external documents","Minimal cross-referencing (only to two manufacturer service bulletins and one related foreign directive)"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection and eventual retirement of the horizontal stabilizer (part 355A13.0520.01.01) on Eurocopter AS 355 helicopters per the manufacturer’s service bulletins. It affects operators using that stabilizer (exempting the reinforced part 315A13.0520.02.01) to prevent bolt‑hole elongation and fatigue cracks that have caused overseas failures. Vulnerable stabilizers face retirement limits (high‑time units soon after 600 hours; low‑time by 700 total hours)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment introduces a mandatory life limitation and retirement schedule for horizontal stabilizer P/N 355A13.0520.01.01 (implements the life limitation of SB 01.10), adding inspection and removal timing requirements where those limits were not previously mandated in this AD."},"complexity_factors":["Narrow technical applicability: specific helicopter model with a single stabilizer part number (P/N 355A13.0520.01.01)","Two discrete mandatory actions (inspect per Aerospatiale Telex SB 05.10A; retire per Aerospatiale SB 01.01) creating operational steps to follow","Conditional retirement schedule based on hours-in-service (different rules for >600 hours versus <600 hours, with a historic deadline of 30 April 1984)","Dependence on external manufacturer service documents for procedural detail (SB 05.10A and SB 01.01)","Exclusion clause for reinforced part number (P/N 315A13.0520.02.01) requiring parts-level record checks","Safety-critical engineering rationale (fatigue from bolt‑hole elongation) increases procedural strictness and replacement cost impact"],"plain_english_summary":"This airworthiness directive requires operators of Eurocopter AS 355 helicopters fitted with horizontal stabilizer P/N 355A13.0520.01.01 to perform inspections per Aerospatiale Telex SB 05.10A and to retire the stabilizer under the Aerospatiale life‑limit schedule; reinforced P/N 315A13.0520.02.01 is excluded.\n\nIt responds to overseas failures where bolt‑hole elongation initiated fatigue cracking; operators must track hours‑in‑service and replace units by the AD's hour limits (retire within 100 hours if already over 600 hours after 30 April 1984; otherwise by 700 hours)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement","history":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement/history","analysis":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement/analysis","conflicts":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement/conflicts","importantCases":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement/important-cases","documents":"/api/acts/ad-as-355-13-amdt-1-horizontal-stabilizer-inspection-and-retirement/documents"}}