{"id":"F2007L03964","name":"AD/PC-12/50 - Powerplant - Torque Oil Pressure Pipe","slug":"ad-pc-12-50-powerplant-torque-oil-pressure-pipe","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70662,"registerId":"commonwealth-F2007L03964-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pilatus PC-12 Series Aeroplanes","sectionType":"division","heading":"Pilatus PC-12 Series Aeroplanes","content":"### Pilatus PC-12 Series Aeroplanes\n\n| AD/PC-12/50 | Powerplant - Torque Oil Pressure Pipe | 11/2007 |\n| ----------- | ------------------------------------- | ------- |\n\n| Applicability: | Pilatus PC-12, PC-12/45 and PC-12/47 aircraft, all serial numbers, with oil pipe/hose assemblies Part Number (P/N) 577.11.12.104, 577.11.12.105, 946.37.74.305, 946.37.74.306, 946.37.74.307, 946.37.74.308 or 946.37.74.311 installed. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Perform a configuration check and inspection of the pipe/hose assemblies for abrasive damage (chafing) and distortion in accordance with paragraph 3.B of PILATUS PC-12 Service Bulletin No. 71-007.2. If during the configuration check and inspection detailed in Requirement 1 of this AD any oil pipe/hose assemblies with abrasive damage (chafing) are found, replace the affected hose/pipe assemblies in accordance with paragraph 3.B, 3.D and 3.E of PILATUS PC-12 Service Bulletin No. 71-007.3. If during the configuration check and inspection detailed in Requirement 1 of this AD, no damage on oil pipe/hose assemblies is found, replace the hose/pipe assemblies as listed in the applicability of this AD, in accordance with paragraph 3.B, 3.C and 3.E of PILATUS PC-12 Service Bulletin No. 71-007.4. Do not install any oil pipe/hose assembly with P/N 577.11.12.104, 577.11.12.105, 946.37.74.305, 946.37.74.306, 946.37.74.307, 946.37.74.308 or 946.37.74.311 on any PILATUS PC-12 series aircraft.Note: EASA AD 2007-0235 dated 31 August 2007 refers. |\n| Compliance: | 1. Within10 Flight Hours (FH) after the effective date of this AD.2. Before further flight after the effective date of this AD.3. Within 6 months after the effective date of this AD.4. After 14 March 2008. |\n| | This Airworthiness Directive becomes effective on 25 October 2007. |\n| Background: | This AD is prompted by occurrences where abrasive damage (chafing) has been found on oil pipe assemblies in the area of the torque oil pressure transducer on the engines of some PC-12 aircraft. Incorrect assembly after maintenance tasks can decrease distances between various pipe/hoses assemblies and adjacent components. Damaged pipes can cause oil leakages in the area of the engine. |\n\n| | This AD requires an inspection for damage, replacement when damage is found, and eventual replacement of all the affected pipe/hose assemblies. |\n| --- | ----------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nCharles Lenarcic \nDelegate of the Civil Aviation Safety Authority\n\n4 September 2007","sortOrder":0},{"sectionNumber":"AD/PC-12/50","sectionType":"part","heading":"AD/PC-12/50","content":"## AD/PC-12/50","sortOrder":1},{"sectionNumber":"Powerplant - Torque Oil Pressure Pipe","sectionType":"part","heading":"Powerplant - Torque Oil Pressure Pipe","content":"## Powerplant - Torque Oil Pressure Pipe","sortOrder":2},{"sectionNumber":"11/2007","sectionType":"part","heading":"11/2007","content":"## 11/2007","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific safety defect in a specific aircraft type. The scope remains tightly focused on the oil pipe chafing issue identified in the background, with no evidence of scope creep beyond the original safety purpose."},"complexity_factors":["Multiple conditional pathways: different actions required depending on whether damage is found or not (Requirements 1-3)","Four separate compliance deadlines tied to different triggers (flight hours, immediate, months, calendar date)","Seven specific part numbers must be tracked for applicability and prohibition","Cross-reference to external technical document (Pilatus Service Bulletin No. 71-007) for detailed procedures","Reference to related European aviation safety directive (EASA AD 2007-0235)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Pilatus PC‑12 (including PC‑12/45 and PC‑12/47) to inspect specific torque‑pressure oil pipes/hoses for chafing and replace them per Pilatus SB 71‑007. Inspect within 10 flight hours; ground and replace any damaged pipes before further flight, or replace all affected pipes within six months if no damage is found. Those part numbers must not be installed on PC‑12s after 14 March 2008."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD remains narrowly targeted to the original safety issue: abrasive damage (chafing) of oil pipe/hose assemblies near the torque oil pressure transducer on Pilatus PC-12 series aeroplanes. It prescribes inspection and replacement of the same set of part numbers and does not broaden the subject matter beyond that original safety concern. The requirement to replace undamaged listed assemblies within a compliance window and the prohibition on reinstalling the listed P/Ns are consistent with addressing the same identified risk rather than expanding scope to unrelated components."},"complexity_factors":["Single-subject Airworthiness Directive focused on specific hose/pipe part numbers (7 part numbers listed)","Conditional logic: different actions if damage found vs. not found (inspection -> replace if damaged; replace all if not damaged)","Cross-references to external documents: multiple paragraphs (3.B, 3.C, 3.D, 3.E) of Pilatus Service Bulletin No. 71-007 for procedural detail","Several compliance timeframes (inspection within 10 flight hours; replace before further flight if damaged; replace within 6 months if undamaged; installation prohibition effective from a later date)","Some ambiguity in the AD text presentation (numbering of compliance items vs. the Requirement text) requires careful reading to align actions and deadlines"],"plain_english_summary":"**What this directive does (mechanics)\n\n- Requires owners/operators of certain Pilatus PC-12 series aeroplanes to check and/or replace specific engine oil pipe/hose assemblies that run near the torque oil pressure transducer. (See \"Applicability\" and \"Requirement\".)\n\n- Step 1: Perform a configuration check and inspect the listed pipe/hose assemblies for abrasive damage (chafing) and for distortion in accordance with the procedures referenced in Pilatus Service Bulletin No. 71-007 (paragraph 3.B). (Requirement)\n\n- Step 2: If any hose/pipe is found to have abrasive damage (chafing), replace the affected assembly immediately in accordance with Pilatus Service Bulletin No. 71-007 (paragraphs 3.B, 3.D and 3.E). The AD requires replacement before further flight if damage is found. (Requirement; Compliance)\n\n- Step 3: If no damage is found on inspection, the AD still requires replacement of all listed hose/pipe assemblies within the specified compliance window, following the Service Bulletin (paragraphs 3.B, 3.C and 3.E). (Requirement; Compliance)\n\n- Installation prohibition: The AD forbids installing any oil pipe/hose assembly with the listed part numbers on any Pilatus PC-12 series aircraft. (Requirement)\n\n- Compliance timing: carry out the inspection within 10 flight hours of the AD becoming effective; replace any damaged part before further flight; replace undamaged listed assemblies within 6 months; the AD includes an effective date and an applicable later date for the installation prohibition. (Compliance)\n\n\nWho is affected\n\n- Directly: Owners, operators and maintenance organisations responsible for Pilatus PC-12, PC-12/45 and PC-12/47 aeroplanes that currently have any of these oil pipe/hose part numbers installed: P/N 577.11.12.104, 577.11.12.105, 946.37.74.305, 946.37.74.306, 946.37.74.307, 946.37.74.308 or 946.37.74.311. (Applicability)\n\n- Indirectly: Parts suppliers, maintenance workshops and any third-party maintenance providers who will perform the inspections and replacements.\n\n\nWhy it matters (stated purpose and practical risk)\n\n- The AD is prompted by occurrences of abrasive damage (chafing) found on those oil pipe assemblies near the torque oil pressure transducer; incorrect re-assembly after maintenance can reduce clearance and cause chafing. Damaged pipes can leak oil in the engine area, which raises safety and engine-operational risks. (Background)\n\n\nCosts, incentives and trade-offs (practical testing of the stated purpose)\n\n- Who pays: aircraft owners/operators pay for the inspection, parts and labour, and for any aircraft downtime while work is done. Maintenance organisations bear the labour input but receive paid work. Parts suppliers will supply replacement assemblies.\n\n- Incentives created: Operators face a short-term cost (inspection and likely replacement) that reduces the chance of oil leaks and associated operational and safety risk. Because the AD mandates replacement even when no damage is found, operators may choose to comply promptly to avoid regulatory breach and to remove higher-risk part numbers from service.\n\n- Opportunity cost & productivity: Aircraft removed from service for replacement lose available flight hours; small operators may face scheduling disruption. Maintenance capacity and parts availability may constrain how quickly operators can comply.\n\n- Implementation risk: The AD cross‑references specific paragraphs of the Pilatus Service Bulletin for detailed procedures. If replacement parts are scarce or procedures are misinterpreted, compliance delays or improper installations could occur. The AD does not create broad discretionary approvals—work must follow the Service Bulletin instructions.\n\n- Compliance burden & recordkeeping: Operators must schedule an inspection within a short window (10 flight hours), document findings, replace parts as required and ensure no prohibited P/Ns are installed thereafter. This creates a short-term administrative and physical burden but is narrowly targeted.\n\n- Effects on market participants: Maintenance providers gain billable work; suppliers of approved replacement assemblies gain sales. The prohibition on reinstalling the listed P/Ns may shift demand toward the approved replacement parts and suppliers.\n\n\nConcrete behavioural change required\n\n- Maintenance staff must inspect specified oil pipes within the 10 flight-hour window and either replace damaged assemblies before further flight or replace all listed assemblies within the six‑month window if undamaged.\n\n- Operators must ensure the listed P/Ns are not installed on any PC-12 series aeroplane after the stated date.\n\n\nRelevant text pointers\n\n- Applicability: lists the affected airframes and the specific part numbers.\n- Requirement: sets out the inspection and replacement rules and cross-references Pilatus Service Bulletin No. 71-007 (paras 3.B/3.C/3.D/3.E).\n- Compliance: gives timing: inspection within 10 flight hours, replacement before further flight if damage is found, replacement within 6 months if undamaged, and an installation prohibition effective from the stated later date.\n\n\nLimitations and uncertainties\n\n- The AD relies on the Pilatus Service Bulletin for detailed instructions; the AD itself does not reproduce procedural detail, so correct compliance requires access to and correct interpretation of the Service Bulletin.\n\n- The AD does not quantify replacement part lead times or cost, so operators will face variable real-world resource impacts depending on supplier availability and local maintenance capacity.\n\n"},"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-pc-12-50-powerplant-torque-oil-pressure-pipe","history":"/api/acts/ad-pc-12-50-powerplant-torque-oil-pressure-pipe/history","analysis":"/api/acts/ad-pc-12-50-powerplant-torque-oil-pressure-pipe/analysis","conflicts":"/api/acts/ad-pc-12-50-powerplant-torque-oil-pressure-pipe/conflicts","importantCases":"/api/acts/ad-pc-12-50-powerplant-torque-oil-pressure-pipe/important-cases","documents":"/api/acts/ad-pc-12-50-powerplant-torque-oil-pressure-pipe/documents"}}