{"id":"F2007L01366","name":"AD/ROTAX/17 Amdt 2 - Engine Crankcase Cracks","slug":"ad-rotax-17-amdt-2-engine-crankcase-cracks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65665,"registerId":"commonwealth-F2007L01366-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rotax Piston Engines","sectionType":"division","heading":"Rotax Piston Engines","content":"### Rotax Piston Engines\n\n| AD/ROTAX/17 Amdt 2 | Engine Crankcase Cracks | 6/2007 |\n| ------------------ | ----------------------- | ------ |\n\n| Applicability: | Rotax 912 A series engines up to serial number (S/N) 4,410.689 inclusive;Rotax 912 F series engines up to S/N 4,412.914 inclusive;Rotax 912 S series engines up to S/N 4,923.308 inclusive;Rotax 914 F series engines up to S/N 4,420.606 inclusive;And any other Rotax type 912 and 914 series engine whose crankcase assembly has been replaced by a crankcase having an S/N up to S/N 27811 inclusive.                                                                                                                                                                                      |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Carry out an inspection of the engine crankcase for cracks and oil leaks as detailed in BRP-Rotax Mandatory Service Bulletins, SB-912-029 R3 or later approved revision or SB-914-018 R3 or later approved revision as is applicable.In lieu of the inspecting of the engine crankcase assembly a review of the engine logbook or maintenance records is acceptable provide the crankcase serial number can be clearly identified as not been in the serial number range of this AD.Note: EASA AD 2007-0025 dated 1 February 2007 refers. This AD supersedes Austro Control GmbH AD A-2004-01. |\n| Compliance:    | Within 110 flight hours from the last inspection carried out in accordance with the amendment 1 of this AD and thereafter at intervals not to exceed 110 flight hours.                                                                                                                                                                                                                                                                                                                                                                                                                         |\n|                | This Amendment becomes effective on 7 June 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Background:    | The initial issue of this directive addressed an unsafe condition caused by cracks on the Rotax engine crankcases and required inspection at the regular intervals.Amendment 1 addressed the same unsafe condition but expanded the applicability list and additional inspections as detailed in revised Service Bulletin by the manufacturer and the Austrian ACG Airworthiness Directive.Amendment 2 amends the applicability section of this AD and reflects the latest revision of the manufacturer’s service bulletin.                                                                    |\n\n|     | The original issue of this directive became effective on 27 November 2003.Amendment 1 of this AD became effective on 25 November 2004. |\n| --- | -------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n26 April 2007","sortOrder":0},{"sectionNumber":"AD/ROTAX/17 Amdt 2","sectionType":"part","heading":"AD/ROTAX/17 Amdt 2","content":"## AD/ROTAX/17 Amdt 2","sortOrder":1},{"sectionNumber":"Engine Crankcase Cracks","sectionType":"part","heading":"Engine Crankcase Cracks","content":"## Engine Crankcase Cracks","sortOrder":2},{"sectionNumber":"6/2007","sectionType":"part","heading":"6/2007","content":"## 6/2007","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The instrument has expanded beyond the original 2003 directive. Amendment 1 broadened the list of affected engines and added inspection tasks aligned to revised manufacturer guidance. Amendment 2 further amends applicability (additional serial number ranges and a provision covering engines whose crankcase has been replaced by a crankcase with S/N up to 27811) and updates the required manufacturer service bulletin revisions. Concretely, the affected population of engines increased and the AD now imports later bulletin revisions, which widens the operational reach and the set of required inspection procedures compared with the original issue. (Background, Applicability)"},"complexity_factors":["Multiple engine sub‑series with different serial‑number cut‑offs (several 912 and 914 variants listed) in the Applicability clause","Cross‑reference to manufacturer Mandatory Service Bulletins (SB‑912‑029 R3 or later; SB‑914‑018 R3 or later) which import procedural detail by reference","Alternative compliance path (physical inspection OR documentary logbook review) contingent on positive identification of crankcase serial number","Recurring inspection interval with a short period (every 110 flight hours) creating repetitive compliance obligations","Supersession history (original AD, Amendment 1, Amendment 2) requiring readers to track which requirements persist or changed","Potential dependency on later approved revisions of the service bulletins (open‑ended reference to “or later approved revision”)"],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Requires inspections of specified Rotax 912 and 914 series engine crankcases for cracks and oil leaks. (Requirement)\n- Applies to engines of several 912/914 sub‑series up to the serial number limits listed, and to any other 912/914 engine whose crankcase was replaced by a crankcase with a serial number up to S/N 27811. (Applicability)\n- Inspections must be carried out in accordance with BRP‑Rotax Mandatory Service Bulletin SB‑912‑029 R3 (or later) for 912 engines or SB‑914‑018 R3 (or later) for 914 engines. An owner/operator may instead show from engine logbooks or maintenance records that the crankcase serial number is outside the affected range and so avoid the physical inspection. (Requirement)\n- Repeated inspections are mandatory: within 110 flight hours from the last inspection done under the previous amendment and thereafter every 110 flight hours. (Compliance)\n\nWho is affected\n\n- Aircraft owners and operators who have Rotax 912 or 914 series piston engines within the serial‑number ranges stated. (Applicability)\n- Maintenance organisations or individuals who perform engine inspections and repairs, because inspections must follow the manufacturer’s mandatory service bulletin. (Requirement)\n- Regulators and maintenance record‑keepers, because a logbook review is an approved alternative to a physical inspection only if the crankcase serial number can be positively identified. (Requirement)\n\nWhy it matters (stated purpose and operational effect)\n\n- The stated safety objective is to detect crankcase cracks and oil leaks that could lead to engine failure. (Background, Requirement)\n- Mechanically, the AD forces periodic examination or documentary proof that the affected part is not in the fleet, so operators either perform recurrent inspections or produce definitive evidence that their crankcase is outside the affected serial‑number range. (Requirement, Compliance)\n\nHow this changes behaviour, who pays and who decides\n\n- Who pays: aircraft owners/operators bear the direct costs (inspection labour, potential part replacement, aircraft downtime). If a crankcase is found cracked, repair or replacement costs fall on the owner/operator. (Requirement, Compliance)\n- Who decides/acts: the owner/operator arranges the inspection; a suitably qualified maintenance person must carry it out to the manufacturer’s bulletin. The regulator (Civil Aviation Safety Authority) enforces compliance. (Requirement)\n- Behavioural change: more frequent inspections of the listed engines or reliance on accurate maintenance records to avoid inspections. Operators may prefer record‑keeping or earlier replacement of higher‑risk crankcases to avoid repeated inspections. (Requirement, Compliance)\n\nSources' claimed rationale and practical trade‑offs\n\n- Source claim: the AD exists to prevent unsafe conditions arising from crankcase cracks. (Background)\n- Costs and incentives: the AD imposes recurring inspection costs and aircraft downtime; it creates an incentive to ensure clear serial‑number recording or to replace older crankcases. The alternative of a logbook check reduces inspection burden where records are clear, but creates reliance on good record‑keeping. (Requirement)\n- Implementation risks and compliance burden: correctly identifying crankcase serial numbers may be difficult if markings are obscured or records are incomplete, increasing the chance of mandatory physical inspections. The AD also relies on the version of the manufacturer’s service bulletin, which may shift technical requirements over time. (Requirement)\n\nMarket and competition effects (brief)\n\n- The measure is safety‑focused rather than commercially prescriptive, but it can affect private enterprises by raising maintenance costs and potentially increasing demand for certified maintenance providers able to perform the work and validate serial numbers. It does not directly alter market entry, prices for engines, or ownership rules, but it can influence operating costs and scheduling for small operators. (Requirement)\n\nNotes on legal relationships and prior versions\n\n- This Amendment supersedes an earlier Austro Control AD and updates applicability and service bulletin references to reflect the manufacturer’s latest revisions. Amendment 1 previously expanded applicability and inspection requirements; Amendment 2 refines the applicability list and aligns the AD with the latest manufacturer bulletin. (Background)\n\nPractical takeaway\n\n- If you operate or maintain affected Rotax 912/914 engines, you must either follow the listed SB (inspection) or keep unequivocal maintenance records proving your crankcase is outside the affected serial numbers. Inspections repeat every 110 flight hours. Arrange and budget for recurrent inspections and ensure serial numbers are clearly recorded in maintenance logs. (Applicability, Requirement, Compliance)\n"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 2003 directive addressed a specific unsafe condition with crankcase cracks. Amendment 1 in 2004 expanded the applicability list and added additional inspections. This Amendment 2 further expands the applicability section again to cover more engine serial numbers and reflects updated manufacturer service bulletins. The scope has grown from the original targeted fix to a broader ongoing inspection program covering more engine variants and replacement crankcases."},"complexity_factors":["Multiple serial number ranges across four engine series must be checked for applicability","Cross-reference to two different manufacturer service bulletins (SB-912-029 R3 and SB-914-018 R3) with 'or later approved revision' language","Conditional compliance alternative allowing logbook review instead of physical inspection, subject to serial number verification requirement","Reference to external European regulations (EASA AD 2007-0025) and Austrian authority (Austro Control GmbH AD A-2004-01)","Amendment structure requires understanding of previous versions (Amendment 1 and original issue) to fully grasp current requirements","Flight-hour-based compliance calculation requires tracking hours since last inspection under previous amendment"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of certain Rotax 912/914 piston engines (specific crankcase serial ranges) to inspect the crankcase for cracks and oil leaks per the manufacturer's service bulletin, or alternatively verify by records that the crankcase serial number is outside the affected range.  \n\nInspections must begin within 110 flight hours and repeat every 110 hours. It prevents engine failure and in-flight emergencies; Amendment 2 expands coverage based on new manufacturer and European authority information."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks","history":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks/history","analysis":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks/analysis","conflicts":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks/conflicts","importantCases":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks/important-cases","documents":"/api/acts/ad-rotax-17-amdt-2-engine-crankcase-cracks/documents"}}