{"id":"F2006B06101","name":"AD/PC-12/38 - MLG Shock Absorber Attachment Bolts","slug":"ad-pc-12-38-mlg-shock-absorber-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46844,"registerId":"commonwealth-F2006B06101-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 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\n![](image.001.png)  \n\nPilatus PC-12 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/PC-12/38 MLG Shock Absorber Attachmen","sectionType":"part","heading":"AD/PC-12/38 MLG Shock Absorber Attachment Bolts 13/2003","content":"# AD/PC-12/38 MLG Shock Absorber Attachment Bolts 13/2003\n\nDM\n\nApplicability: All Model PC-12 and PC-12/45 aircraft, Manufacturer Serial Numbers 101 through 482.\n\nRequirement: 1. Inspect the left and right main landing gear assemblies, part numbers 532.10.12.049 and 532.10.12.050, and determine if the serial numbers start with the letters AM. Pilatus Aircraft Service Bulletin (SB) 32-015 refers.\n\nIf both main landing gear assembly serial numbers do not start with the letter AM, no further action is required.\n\n2. If the inspection reveals a main landing gear assembly serial number that starts with the letter AM, replace the main landing gear(s) shock absorber attachment bolts with new bolts in accordance with SB 32-015.\n\nNo spare main landing gear assembly, part number 532.10.12.049 or 532.10.12.050 with a serial number that starts with the letters AM, shall be installed unless attachment bolts part number 532.10.12.110 have been replaced with new bolts in accordance with SB 32-015.\n\nNote: FOCA AD HB 2003-522 refers.\n\nCompliance: 1. Within 100 hours time in service or 30 days after 19 November 2003, whichever occurs first.\n\n2. Before further flight.\n\nThis Airworthiness Directive becomes effective on 19 November 2003.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive remains narrowly focused on correcting an identified unsafe condition in specific MLG assemblies (those with serial numbers starting 'AM') on a defined range of PC-12/PC-12/45 airframes. It does not broaden the subject matter beyond inspection and bolt replacement, nor does it add unrelated compliance obligations. Therefore the scope has not materially changed beyond the original safety-focused purpose."},"complexity_factors":["Applicability limited to PC-12 / PC-12/45 MSNs 101–482 (narrow scope)","Single conditional inspection step (check for serials starting with 'AM')","Single corrective action (replace shock absorber attachment bolts per SB 32-015)","Explicit compliance deadlines (100 flight hours or 30 days for inspection; replacement before next flight)","Cross-reference to Pilatus Service Bulletin 32-015 for procedural detail (technical steps not contained in AD)","Prohibition on installing spare MLGs with 'AM' serials unless bolts replaced (one additional operational condition)","Minor external cross-reference to FOCA AD HB 2003-522"],"plain_english_summary":"**What this directive does (mechanically)\n\n- Applies to: all Pilatus PC-12 and PC-12/45 aeroplanes with manufacturer serial numbers (MSN) 101 through 482. (See “Applicability”.)\n\n- Inspect: examine the left and right main landing gear (MLG) assemblies (part numbers 532.10.12.049 and 532.10.12.050) and check whether their serial numbers start with the letters \"AM\". (Requirement 1.)\n\n- Replace if necessary: if either MLG assembly has a serial number starting with \"AM\", replace the shock absorber attachment bolts with new bolts as directed by Pilatus Service Bulletin (SB) 32-015. (Requirement 2.)\n\n- Spare gears rule: do not install any spare MLG assembly (part number 532.10.12.049 or 532.10.12.050) that has a serial number beginning with \"AM\" unless the attachment bolts (part number 532.10.12.110) on that spare have been replaced in accordance with SB 32-015. (Requirement 2.)\n\n- Timing (Compliance): carry out the inspection within 100 flight hours or 30 days after 19 November 2003 (whichever comes first). If replacement is required, it must be done before the next flight. (Compliance.)\n\n- Procedure reference: follow the detailed replacement/inspection instructions in Pilatus Service Bulletin 32-015. A corresponding Swiss FOCA AD (HB 2003-522) is also noted. (Requirement notes.)\n\nWhy this matters (stated purpose and mechanical effect)\n\n- Purpose claimed by the directive: to correct an identified unsafe condition related to the shock absorber attachment bolts on certain MLG assemblies. The AD achieves that by requiring inspection and replacement of those bolts where affected parts are identified. (Background + Requirement.)\n\nWho is directly affected and who pays\n\n- Aircraft operators and owners of PC-12/PC-12/45 within the listed MSN range must ensure inspection and, if necessary, replacement. Their maintenance organisation must perform the work to the Pilatus SB.\n\n- The cost of parts, labour and any aircraft downtime is borne by the aircraft owner/operator. Maintenance organisations decide how to schedule and carry out the work (subject to regulatory compliance). The regulator (CASA delegate) enforces compliance by issuing the AD. (Applicability, Requirement, Compliance.)\n\nImplementation, trade-offs and practical consequences\n\n- Operational impact: most aircraft will only need a short inspection; aircraft with affected MLGs will require bolt replacement and be grounded until replacement is done (replacement is required before further flight). The inspection window (100 hours or 30 days) caps the short-term operational disruption.\n\n- Supply and logistics: demand for the specified replacement bolts (part number 532.10.12.110) may rise; operators with spare MLG assemblies must check and, if necessary, replace bolts before installing those spares.\n\n- Compliance mechanics: the AD references Pilatus SB 32-015 for exact procedures. That means the maintenance method, torque, parts sourcing and record-keeping follow the manufacturer's instructions rather than being fully specified within the AD itself.\n\n- Enforcement and discretion: CASA (via the delegate) mandates the action; approved maintenance organisations will execute it. The AD sets mandatory outcomes (inspection, replacement if \"AM\" serials are found), but relies on the SB for specific technical steps.\n\nRisks, incentives and opportunity costs\n\n- Who benefits/concentrates benefits: aircraft that have the affected part replaced gain reduced immediate risk associated with the identified condition. The benefit is concentrated to operators of aircraft with \"AM\"-prefix MLG assemblies.\n\n- Diffuse costs: all affected operators share the compliance cost, even if an individual aircraft passes the inspection with no replacement needed.\n\n- Behavioural effect: operators with affected spares may delay installing those spares until bolts are replaced, and maintenance providers will schedule bolt replacement work promptly to return aircraft to service.\n\n- Opportunity cost: aircraft downtime and maintenance resource allocation that could otherwise be used for other work.\n\nBottom line (mechanics first, then rationale): This AD requires operators of Pilatus PC-12/PC-12/45 (MSN 101–482) to inspect their main landing gear assemblies for a specific serial-number prefix and to replace the shock absorber attachment bolts on any gear whose serial number begins with \"AM\", following Pilatus SB 32-015. The goal (as stated) is to correct an unsafe condition; the immediate effects are inspection work, targeted bolt replacement where necessary, and a prohibition on installing unmodified spare MLGs with the same serial-number prefix until the bolts are changed. (Requirement 1–2; Compliance.)"},"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":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in shock absorber attachment bolts for a limited production run of PC-12 aircraft. The spare parts provision is a logical extension of the safety requirement rather than scope creep."},"complexity_factors":["Single, clearly defined applicability (specific aircraft models and serial number range)","Simple binary decision tree (check serial numbers → if 'AM' then replace, if not then stop)","Only 2 defined part numbers referenced","Single cross-reference to manufacturer Service Bulletin 32-015","No nested exceptions or conditional logic beyond the initial serial number check","Straightforward compliance timeframe with clear alternatives (100 hours OR 30 days)","Total length is approximately 250 words"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Pilatus PC-12 and PC-12/45 (S/N 101–482) to address defective main landing gear shock absorber attachment bolts that could cause gear collapse. Operators must inspect gear assembly serials for the \"AM\" prefix and, if present, replace the bolts per Pilatus Service Bulletin 32‑015; assemblies without \"AM\" need no action. Compliance for in-service aircraft is within 100 flight hours or 30 days after 19 November 2003; spare \"AM\" gear may not be installed unless bolts are replaced."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts","history":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts/history","analysis":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts/analysis","conflicts":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts/conflicts","importantCases":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts/important-cases","documents":"/api/acts/ad-pc-12-38-mlg-shock-absorber-attachment-bolts/documents"}}