{"id":"F2006B07105","name":"AD/S-PUMA/28 Amdt 4 - Engine to Main Gearbox Coupling","slug":"ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48890,"registerId":"commonwealth-F2006B07105-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/S-PUMA/28 Amdt 4 - Engine to Main Gearbox Coupling","content":"![](image.001.png)![](image.001.png)AIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD)\n\n![](image.001.png)AD/S-PUMA/28 Amdt 3 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nEurocopter AS 332 (Super Puma) Series Helicopters\n\nAD/S-PUMA/28\n\nAmdt 4\n\n  \nEngine to Main Gearbox Coupling 5/2002\n\nApplicability: All Eurocopter AS 332C, C1, L and L1 Super Puma helicopters.\n\nRequirement: Action in accordance with Eurocopter AS332 Alert Service Bulletin (ASB) No.\n\n63.00.58 Revision 4, paragraph 2B (1 to 8).\n\nNote: DGAC 1999-257-074 (A)R5 refers.\n\nCompliance: As detailed in the Requirement document.\n\nThis amendment becomes effective on 16 May 2002.\n\nBackground: This Directive was originally issued to address reports of engine to main gearbox coupling failures. Coupling failure was identified as a cause of an AS332L1 accident in the North Sea in September 1997.\n\nThis amendment reflects Revision 4 of Service Bulletin 63.00.58. The revision, in part, cancels the requirement to carry out a vibration check on aircraft incorporating mod 0726197 (TU215) and mod 0752318, the new splined coupling.\n\nAmendment 3 was issued to cancel the 25 hour vibration level check for aircraft modified in accordance with MOD 0726070 or 0726075 (Turbomeca Mod TU 203 refers).\n\nAmendment 2 was issued to further limits the inspection to certain coupling shafts and redefines the compliance requirements.\n\nAmendment 1 refined the original issue directive and stated steady state inspection requirements for the engine to main gearbox coupling.\n\nAmendment 3 of this Airworthiness Directive became effective on 13 July 2000. Amendment 2 of this Airworthiness Directive became effective on 7 October 1999.\n\nEurocopter AS 332 (Super Puma) Series Helicopters\n\nAD/S-PUMA/28 Amdt 4 (Continued)\n\nThe original issue of this Directive became effective on 10 October 1997.\n\n![Signature of Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 26 March 2002\n\n![](image.001.png)The above AD is notified in the Commonwealth of Australia Gazette on 24 April 2002.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Scope has been narrowed and refined since the original 1997 issue. Revision 4 cancels the vibration check for aircraft incorporating MOD 0726197 (TU215) and MOD 0752318, the new splined coupling (Background). Amendment 3 cancelled a 25‑hour vibration level check for aircraft modified under MOD 0726070 or 0726075, and Amendment 2 limited inspections to certain coupling shafts and redefined compliance requirements (Background). Applicability remains all AS332 C/C1/L/L1 types, but inspection obligations and required checks have been reduced or targeted for specific modified aircraft (Applicability; Background)."},"complexity_factors":["Dependence on an external technical document for mandatory action (Eurocopter AS332 ASB No. 63.00.58 Revision 4) (Requirement).","Multiple prior amendments that alter inspection types and timing, creating a patchwork of exceptions and exemptions (Background: Amendments 1–3 described).","Technical and maintenance work requires specialist skills, parts and access to maintenance records, increasing operational burden on operators (Requirement; Compliance).","Applicability covers all AS332C/C1/L/L1 models but several specific mods are carved out or treated differently, increasing compliance-check complexity (Applicability; Background).","Compliance timing is delegated to the CASA directive and cross-referenced to the ASB rather than stated explicitly in the AD text, requiring operators to consult the ASB for deadlines (Compliance).","Regulatory authority is exercised under subregulation 39.1(1) of CAR 1998, indicating administrative discretion in issuing/revoking ADs (preamble)."],"plain_english_summary":"This directive requires operators of Eurocopter AS332 C, C1, L and L1 helicopters to carry out the actions in Eurocopter Alert Service Bulletin No. 63.00.58 Revision 4 to inspect, monitor and where necessary modify the engine‑to‑main‑gearbox coupling to address reported coupling failures. CASA's delegate sets the compliance timing; operators bear the cost of inspections, vibration checks and any replacements. Revision 4 removes some vibration‑check requirements for aircraft fitted with specified modifications or the new splined coupling (Requirement; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The legislation remains tightly focused on its original purpose: preventing engine-to-gearbox coupling failures in Super Puma helicopters. While this is the fourth amendment over five years, each iteration has refined rather than expanded the scope — Amendment 4 actually narrows requirements by exempting modified aircraft from vibration checks. The scope has not grown beyond the original safety intent."},"complexity_factors":["Short, single-purpose instrument (approximately 300 words)","Only 4 defined/modified terms (the modification numbers: 0726197/TU215, 0752318, 0726070, 0726075/TU203)","Simple structure: Applicability → Requirement → Compliance → Background","Single cross-reference to Eurocopter Alert Service Bulletin 63.00.58 Rev 4 and DGAC 1999-257-074 (A)R5","No nested exceptions or conditional logic — the amendment actually *removes* a previous requirement rather than adding complexity","Background section provides clear historical context but does not create legal obligations"],"plain_english_summary":"The Australian regulator has revoked Amendment 3 and issued Amendment 4 of AD/S‑PUMA/28, requiring owners/operators of Eurocopter AS 332C/C1/L/L1 Super Puma helicopters to follow Eurocopter Alert Service Bulletin No. 63.00.58 Rev 4. The AD addresses dangerous engine‑to‑main‑gearbox coupling failures (linked to a fatal 1997 North Sea accident).\n\nAmendment 4 relaxes one obligation: helicopters with the new splined coupling modifications no longer must perform the previously required vibration check."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling","history":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling/history","analysis":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling/analysis","conflicts":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling/conflicts","importantCases":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling/important-cases","documents":"/api/acts/ad-s-puma-28-amdt-4-engine-to-main-gearbox-coupling/documents"}}