{"id":"F2006B06306","name":"AD/PORSCHE/3 - Valve Springs","slug":"ad-porsche-3-valve-springs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47416,"registerId":"commonwealth-F2006B06306-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PORSCHE/3 - Valve Springs","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPorsche Piston Engines\n\nAD/PORSCHE/3 Valve Springs 13/98 TX\n\nApplicability: Porsche PFM 3200 N01 and N03 engines.\n\nRequirement: To address a report of a broken valve spring resulting in a complete engine failure:\n\nA: By reviewing engine records, determine the operating hours of the cylinder heads, and\n\nB: in accordance with the instructions detailed in Porsche PFM 3200 Service Bulletin Number N/105-036, replace engine valve springs installed in cylinder heads which have a time in service greater than 500 hours .\n\nNote: German LBA Airworthiness Directive AD 1998-436 refers.\n\nCompliance: Unless previously accomplished; before further flight.\n\nThis Airworthiness Directive becomes effective on 19 October 1998.\n\nBackground: This directive has been issued to require the replacement of cylinder head valve springs which have been in service for greater than 500 hours. The requirement reflects a report of an engine failure in flight which resulted from a broken valve spring.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive addressing a specific mechanical failure mode in specific engine models. It has not expanded beyond its original purpose of mandating valve spring replacement to prevent engine failure."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined applicability criteria (specific engine models)","Simple two-step compliance requirement (check records, replace if over threshold)","Single cross-reference to German authority document (informational only)","No nested conditions, exceptions, or defined terms section","Clear binary compliance trigger (500 hours threshold)","Immediate effective date with no phased implementation"],"plain_english_summary":"This is a **safety order** (called an \"Airworthiness Directive\") issued by Australia's aviation safety regulator for specific **Porsche aircraft engines**.\n\n**What it does:**\n- **Targets:** Owners or operators of aircraft with Porsche PFM 3200 N01 or N03 piston engines\n- **The problem:** A valve spring broke during flight, causing complete engine failure (obviously very dangerous when you're airborne)\n- **The fix:** Before flying again, you must:\n  1. Check your engine records to see how many hours the cylinder heads have been used\n  2. Replace any valve springs in cylinder heads that have clocked more than 500 hours of operation, following Porsche's official service instructions (Service Bulletin N/105-036)\n\n**Why it matters:**\nThis is an **immediate safety mandate** (\"before further flight\"). If you ignore it and fly with old valve springs, you risk catastrophic engine failure mid-air. The directive references a German aviation safety notice (LBA AD 1998-436), showing this was an international safety concern.\n\n**Key takeaway:** If you own one of these Porsche aircraft engines, you cannot legally fly until you've checked your cylinder head hours and replaced springs on any high-time components."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Scope remains aligned with the directive's stated purpose: review cylinder‑head hours and replace valve springs with time in service greater than 500 hours on Porsche PFM 3200 N01 and N03 engines, as required in the Background and Requirement sections."},"complexity_factors":["Narrow applicability to specific engine models (Porsche PFM 3200 N01 and N03) reduces breadth of application.","Single, clear threshold for action (>500 hours) simplifies decision-making.","Requires review of engine records to determine hours — imposes a record‑verification compliance task.","Mandates replacement 'before further flight' — immediate compliance deadline can create operational downtime.","Procedural dependency on external Porsche Service Bulletin N/105-036 for how to perform replacements.","No discretionary exemptions or alternative compliance paths stated in the directive.","Enforcement and effectivity are immediate (effective date 19 October 1998) under CASA's AD framework.","References foreign authority (German LBA AD 1998-436) as related material.","Triggered by a single reported failure, reflecting a reactive safety measure rather than a staged inspection regime."],"plain_english_summary":"**What it does:** Requires operators of Porsche PFM 3200 N01 and N03 engines to check cylinder‑head operating hours and replace valve springs that have accumulated more than 500 hours, following Porsche Service Bulletin N/105‑036. Compliance is required before further flight.\n\n**Who pays and who acts:** Operators/owners bear the cost; licensed maintenance organisations must carry out the replacements. The directive was issued after a reported in‑flight engine failure attributed to a broken valve spring."}},"importantCases":[],"_links":{"self":"/api/acts/ad-porsche-3-valve-springs","history":"/api/acts/ad-porsche-3-valve-springs/history","analysis":"/api/acts/ad-porsche-3-valve-springs/analysis","conflicts":"/api/acts/ad-porsche-3-valve-springs/conflicts","importantCases":"/api/acts/ad-porsche-3-valve-springs/important-cases","documents":"/api/acts/ad-porsche-3-valve-springs/documents"}}