{"id":"F2006B05926","name":"AD/PA-36/1 - Wing Spar Centre Section Bolts - Replacement","slug":"ad-pa-36-1-wing-spar-centre-section-bolts-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136011,"registerId":"commonwealth-F2006B05926-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-36/1 - Wing Spar Centre Section Bolts - Replacement","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Piper PA-36 (Pawnee Brave) Series Aeroplanes\n\n \n\nAD/PA-36/1 Wing Spar Centre Section Bolts - Replacement 8/74\n\nApplicability: Model PA-36-285 with S/Nos. 36-7360001 to 36-7460016 not incorporating Piper Kit No. 760871V.\n\n \n\nDocument : Piper SB No. 425.\n\n \n\nCompliance: Within 10 hours time in service after 5 July 1974.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a limited production run of agricultural aircraft. It has not expanded beyond its original purpose of mandating a single bolt replacement to prevent wing spar failure."},"complexity_factors":["Extremely short document (under 200 words)","Only 4 operative provisions: applicability, reference document, compliance deadline, and affected aircraft identification","Single condition in applicability (serial number range plus kit exclusion)","No defined terms section — all terms are standard aviation nomenclature","No cross-references to other legislation beyond the enabling regulation (CAR 1998 Part 39)","No nested exceptions or conditional logic — straightforward command structure","Clear, unambiguous compliance deadline (10 hours TIS after fixed date)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific **Piper PA-36 \"Pawnee Brave\" aircraft** to replace certain bolts in the wing spar centre section. The wing spar is the main structural beam that runs through the wing and attaches it to the fuselage — if these bolts fail, the wing could separate from the aircraft in flight.\n\n**Who it affects:** \n- **Specific aircraft only:** Piper PA-36-285 model planes with serial numbers from 36-7360001 to 36-7460016\n- **Exclusion:** Aircraft that have already been modified with \"Piper Kit No. 760871V\" don't need to comply (the kit presumably fixes the problem)\n\n**What must be done:** Replace the specified bolts within **10 hours of flying time** after 5 July 1974.\n\n**Why it matters:** This is a **critical safety issue**. The directive references **Piper Service Bulletin No. 425**, which means the manufacturer identified a defect that could lead to structural failure. Non-compliance means the aircraft cannot legally fly — it's \"grounded\" until fixed.\n\n**Key point:** This is not optional maintenance advice. It's a **legally enforceable command** backed by aviation law. Flying without compliance risks certificate cancellation, fines, and catastrophic accident liability."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Based on the supplied text, the directive sets a specific, limited scope (part replacement for listed serial numbers excluding those with Kit No. 760871V). The supplied instrument does not indicate any expansion or reduction of that scope from an earlier statement; therefore no change from the originally articulated scope is apparent in this text."},"complexity_factors":["Very narrow applicability limited to a specific model and serial number range (Applicability).","Short and absolute compliance window (10 hours time in service after 5 July 1974) increases scheduling urgency (Compliance).","Reliance on an external service bulletin for technical steps (Document: Piper SB No. 425) requires operators to obtain and follow that separate document.","Need to verify whether Piper Kit No. 760871V is installed to determine applicability (Applicability).","No alternative compliance, phased timing, or conditional exemptions stated in the supplied text (no mitigating procedures provided)."],"plain_english_summary":"### What this instrument does (mechanical change)\n\nThis Airworthiness Directive (AD/PA-36/1) requires replacement of the wing spar centre section bolts on a defined set of Piper PA-36 (Pawnee Brave) aeroplanes. It applies only to Model PA-36-285 aircraft with serial numbers 36-7360001 through 36-7460016 that do not already have Piper Kit No. 760871V installed (Applicability: Model PA-36-285 with S/Nos. 36-7360001 to 36-7460016 not incorporating Piper Kit No. 760871V). The AD directs compliance within 10 hours time in service after 5 July 1974 (Compliance: Within 10 hours time in service after 5 July 1974). The technical instructions to carry out the replacement are referenced to Piper SB No. 425 (Document: Piper SB No. 425).\n\n### Who it affects\n\n- Owners and operators of the specified PA-36-285 serial numbers that do not have the stated kit installed.\n- Maintenance organisations or technicians who perform the replacement work following the referenced service bulletin.\n- The regulator that issued the AD as part of the civil aviation airworthiness system (Commonwealth of Australia; Civil Aviation Safety Authority schedule of Airworthiness Directives).\n\n### Why it matters (stated purpose and practical effects)\n\n- The AD's action is to force a mechanical change: removal and replacement of specific wing-spar centre-section bolts as described in the referenced Piper service bulletin (Document: Piper SB No. 425). The supplied text does not include an explanation of the underlying failure mode or incident that prompted the directive.\n\n- The directive makes the replacement mandatory for the listed aircraft within a brief operational window (10 hours time in service after 5 July 1974), which affects scheduling and maintenance planning (Compliance: Within 10 hours time in service after 5 July 1974).\n\n### Who pays, who decides, and what must change in behaviour\n\n- The aircraft owner/operator bears the direct cost of parts, labour and any downtime required to perform the replacement (the AD mandates the replacement action; costs are not specified in the text). (Applicability..., Compliance...)\n- The Civil Aviation Safety Authority (via the AD) decides the regulatory requirement; the operator/maintenance organisation must implement it. (Commonwealth of Australia (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY; SCHEDULE OF AIRWORTHINESS DIRECTIVES)\n- Operators must identify whether their aircraft fall within the serial-number range and whether Piper Kit No. 760871V is already installed. If the aircraft is within the range and lacks the kit, the operator must schedule and complete the bolt replacement within the 10 hours TIS window. (Applicability..., Compliance...)\n\n### Compliance burden, implementation risks and trade-offs\n\n- Compliance burden: locating serial number records, confirming kit status, obtaining the correct parts/procedures (per Piper SB No. 425), and performing the work rapidly within the 10-hour TIS window will impose administrative and labour costs on affected operators. (Applicability..., Document..., Compliance...)\n- Opportunity cost: aircraft may be unavailable for operations while maintenance is carried out; operators must prioritise the work within the short compliance window. (Compliance...)\n- Dependence on external instructions: the AD points to Piper SB No. 425 for the technical steps; operators must obtain and follow that service bulletin to comply. (Document: Piper SB No. 425)\n- Enforcement and operational risk: failure to comply within the stated window would leave the operator non‑compliant with the AD; the text does not set out enforcement measures or alternative compliance methods.\n\n### Concentration of effects and potential implementation issues\n\n- The requirement targets a narrowly defined group of aircraft (specific serial numbers and exclusion for a named kit), so the direct burden is concentrated on a small set of operators. (Applicability...)\n- The AD does not specify parts availability, cost, or the precise replacement procedure in the supplied text; operators must consult Piper SB No. 425 for those details. (Document: Piper SB No. 425)\n\n### Source citations (from the supplied text)\n\n- Title and identifier: AD/PA-36/1 Wing Spar Centre Section Bolts - Replacement 8/74\n- Applicability: Model PA-36-285 with S/Nos. 36-7360001 to 36-7460016 not incorporating Piper Kit No. 760871V. (Applicability...)\n- Document referenced: Piper SB No. 425. (Document: Piper SB No. 425)\n- Compliance timing: Within 10 hours time in service after 5 July 1974. (Compliance...)\n\n(Analyst note: the supplied text is limited to the directive instructions, applicability and compliance time; it does not include technical justification, cost estimates, or enforcement details.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement","history":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement/history","analysis":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement/analysis","conflicts":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement/conflicts","importantCases":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement/important-cases","documents":"/api/acts/ad-pa-36-1-wing-spar-centre-section-bolts-replacement/documents"}}