{"id":"F2006B07117","name":"AD/S-PUMA/41 Amdt 2 - Main Gearbox Bevel Gear","slug":"ad-s-puma-41-amdt-2-main-gearbox-bevel-gear","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48926,"registerId":"commonwealth-F2006B07117-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Compliance: 1. Installed MGB’s incorpora","sectionType":"part","heading":"Compliance: 1. Installed MGB’s incorporating bevel gears which have logged more than 6,600 flight hours:","content":"# Compliance: 1. Installed MGB’s incorporating bevel gears which have logged more than 6,600 flight hours:\n\nWithin 50 flight hours from the effective date of this Directive, thereafter at intervals not to exceed 150 flight hours or 1000 torque application cycles for helicopters performing external load carrying missions, whichever occurs first, from the effective date of this Directive.\n\nFor MGB’s where the torque application cycles exceed 1000 cycles since the last borescope inspection was carried out; within 300 torque application cycles.","sortOrder":0},{"sectionNumber":"2. Installed MGB’s incorporating bevel g","sectionType":"part","heading":"2. Installed MGB’s incorporating bevel gears which have logged less than 6,600 flight hours:","content":"# 2. Installed MGB’s incorporating bevel gears which have logged less than 6,600 flight hours:\n\nPrior to reaching 6,600 flight hours, thereafter at 150 flight hour intervals or 1000 torque application cycles on helicopters that perform external load carrying missions, whichever occurs first.","sortOrder":1},{"sectionNumber":"Eurocopter AS 332 (Super Puma) Series He","sectionType":"part","heading":"Eurocopter AS 332 (Super Puma) Series Helicopters","content":"# Eurocopter AS 332 (Super Puma) Series Helicopters\n\nAD/S-PUMA/41 Amdt 2 (continued)","sortOrder":2},{"sectionNumber":"3. Spare MGB’s incorporating bevel gears","sectionType":"part","heading":"3. Spare MGB’s incorporating bevel gears that have logged more than 6,600 flying hours and held as spares and have been in service since last overhaul:","content":"# 3. Spare MGB’s incorporating bevel gears that have logged more than 6,600 flying hours and held as spares and have been in service since last overhaul:\n\nPrior to fitment, thereafter at 150 flight hour intervals or 1000 torque application cycles on helicopters that perform external load carrying missions, whichever occurs first.","sortOrder":3},{"sectionNumber":"4. Spare MGB’s incorporating bevel gears","sectionType":"part","heading":"4. Spare MGB’s incorporating bevel gears that have logged more than 6,600 flying hours and have not been installed since last overhaul:","content":"# 4. Spare MGB’s incorporating bevel gears that have logged more than 6,600 flying hours and have not been installed since last overhaul:\n\nWithin 150 flight hours of installation, thereafter at 150 flight hour intervals or 1000 torque application cycles on helicopters that perform external load carrying missions, whichever occurs first.\n\nNote 2: External Load Carrying missions are defined as those missions where a torque application frequency of more than 4 cycles per hour.\n\nThis Amendment becomes effective on 30 October 2003.\n\nBackground: This Amendment amends the inspection interval to take into consideration the stress imposed on the MGB bevel gear during external load missions. External load missions will increase the growth rate of any cracks that have formed. An increase in the number of inspections will be required for helicopters involved in such operations to prevent failure of the bevel gear.\n\nAdvice has been received from the manufacturer that a cracked bevel gear was discovered following detection of metal particles on the magnetic plug. Until the cause of the cracking can be determined a repetitive inspection has been put in place to prevent in flight failure of the bevel gear.\n\nAmendment 1 of this Airworthiness Directive became effective on 23 January 2003.\n\nThe original issue of this Airworthiness Directive became effective on 3 October 2002.\n\n![Signature of Jim Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 19 September 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 8 October 2003.","sortOrder":4}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This amendment modifies existing inspection intervals to account for stresses from external‑load operations by introducing torque application cycle thresholds and more frequent inspections for affected helicopters, and it specifies separate inspection timing for spare MGBs depending on service/installation status (Background; Compliance 1–4; Note 2)."},"complexity_factors":["Multiple conditional inspection thresholds based on logged flight hours (> or < 6,600 fh) (Compliance 1 & 2).","Dual triggering metrics: calendared flight‑hour intervals versus torque application cycles; whichever occurs first introduces operational complexity (Compliance 1 & 2).","Special shorter requirement when torque application cycles have already exceeded 1,000 since last borescope inspection (Compliance 1, para 2).","Separate rules for spare MGBs depending on whether they were held in service since last overhaul or not installed since last overhaul, with differing timing before first use and thereafter (Compliance 3 & 4).","Operational definition of 'External Load Carrying missions' (torque application frequency >4 cycles/hour) creates a monitoring and classification burden for operators (Note 2).","Transition and effective‑date sequencing (amendment effective 30 Oct 2003; earlier AD effective dates) requires operators to map prior compliance history against the new intervals.","Implementation burden: tracking torque-application cycles per aircraft, recording borescope inspections, and scheduling downtime for repetitive inspections increase maintenance and administrative effort.","Enforcement focus on detection (borescope inspection) rather than prescriptive remediation leaves discretion about follow‑up actions to operators and approved maintenance organisations, requiring clear procedures."],"plain_english_summary":"This directive requires repeated borescope inspections of the main gearbox (MGB) bevel gear on Eurocopter AS332 (Super Puma) helicopters. Inspection timing depends on whether a bevel gear has logged more or less than 6,600 flight hours, and on torque-application cycles for helicopters that carry external loads. It applies to installed and spare MGBs and aims to detect cracking after metal-particle detection so operators can prevent in‑flight bevel-gear failure."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original directive (October 2002) established baseline inspection requirements following discovery of cracked bevel gears. Amendment 1 (January 2003) modified these intervals. This Amendment 2 significantly narrows the scope by introducing a mission-specific variable — external load carrying operations — which imposes stricter inspection intervals based on torque cycle frequency rather than flight hours alone. The scope has shifted from a uniform time-based inspection regime to a hybrid time/cycle-based system with operational modifiers, reflecting evolving technical understanding of failure modes under different stress conditions."},"complexity_factors":["Four distinct compliance categories based on flight hours and installation status (installed vs. spare, pre/post 6,600 hours)","Dual measurement systems requiring comparison (flight hours vs. torque application cycles) with 'whichever occurs first' logic","Nested conditional logic for external load carrying missions (defined as >4 torque cycles/hour) affecting interval calculations","Special sub-exception for gearboxes exceeding 1,000 torque cycles since last inspection (300-cycle deadline)","Cross-references to previous amendments (Amendment 1 and original issue) without reproducing their full text","Technical aviation terminology requiring domain knowledge (borescope inspection, magnetic plug, torque cycles, MGB)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators and maintainers of Eurocopter AS 332 Super Puma helicopters (and holders of spare main gearboxes) to perform regular borescope inspections of the main gearbox bevel gear. It responds to detected cracking after metal debris was found, addressing a risk of catastrophic gearbox failure—especially for aircraft on heavy external-load missions—by enforcing frequent inspections until the cause is resolved."}},"importantCases":[],"_links":{"self":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear","history":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear/history","analysis":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear/analysis","conflicts":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear/conflicts","importantCases":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear/important-cases","documents":"/api/acts/ad-s-puma-41-amdt-2-main-gearbox-bevel-gear/documents"}}