{"id":"F2006B10313","name":"AD/GOV/6 - Governor Pressure Relief Valve Roll Pin - Modification","slug":"ad-gov-6-governor-pressure-relief-valve-roll-pin-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56051,"registerId":"commonwealth-F2006B10313-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GOV/6 - Governor Pressure Relief Valve Roll Pin - Modification","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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propeller Governors\n\n \n\nAD/GOV/6 Governor Pressure Relief Valve Roll Pin - Modification\n\n\n8/79\n\n \n\nApplicability:  All McCauley governors model C290D3/T(), C290D4/T(), CF() () 310D2/T(), ()CF()S31D3/T(), DCF()S310D4/T(), DCF()S290D4/T(), DCF() ()290D2/T(), DCF()S290D5/T().\n\n \n\nNote: Production governors already incorporating this modification will have a letter \"A\" in the model number- e.g. C290D3A/T6, while field modified governors will have the suffix letter \"A\" to the serial number.\n\n \n\nDocument: McCauley SB No. 116.\n\n \n\nCompliance: Before installation on an aircraft following the next reconditioning after 31 August 1979.\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 focused on a specific mechanical defect in specific governor models. It has not expanded beyond its original purpose of mandating a single safety modification."},"complexity_factors":["Single, specific technical requirement (one modification to one component)","Clear applicability list (8 governor model families)","Simple compliance trigger (next reconditioning after fixed date)","No defined terms section","No cross-references to other legislation","No conditional logic or exceptions","Straightforward identification method for compliant parts"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) that mandates a safety modification to certain McCauley aircraft propeller governors.\n\n**What it does:**\n- Requires a specific modification to the pressure relief valve roll pin on listed McCauley governor models\n- The modification must be done before the governor is installed on an aircraft following its next reconditioning after 31 August 1979\n\n**Who it affects:**\n- Owners and operators of aircraft using McCauley propeller governors with these specific model numbers: C290D3/T(), C290D4/T(), CF()310D2/T(), CF()S31D3/T(), DCF()S310D4/T(), DCF()S290D4/T(), DCF()290D2/T(), and DCF()S290D5/T()\n- Aircraft maintenance organisations that recondition these governors\n\n**How to identify compliance:**\n- Factory-modified governors have an \"A\" in the model number (e.g., C290D3A/T6)\n- Field-modified governors have an \"A\" suffix added to the serial number\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety orders. Non-compliance means the aircraft cannot legally fly. This particular directive addresses a specific mechanical defect in the pressure relief valve roll pin that could affect propeller control and flight safety.\n\n**Source document:** McCauley Service Bulletin No. 116 provides the technical details for the modification."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD text imposes a targeted modification requirement on a defined set of governor models and sets a compliance timing tied to the next reconditioning after 31 August 1979. The instrument does not indicate any expansion or narrowing of scope relative to an earlier measure; it appears to be a stand‑alone directive establishing the modification requirement and identification convention (Applicability; Note; Compliance; Document)."},"complexity_factors":["Narrow technical scope: single component family (propeller governors) and specific models (Applicability).","External procedural dependence: requires following McCauley SB No. 116 (Document).","Timing constraint tied to maintenance cycles (requires modification at next reconditioning after a fixed date) (Compliance).","Identification rule for modified parts (model/serial number suffix “A”) requires record-keeping and inspection (Note).","Limited textual detail in the AD: no technical rationale or step-by-step method in the AD itself, requiring reliance on the referenced service bulletin (Document)."],"plain_english_summary":"This AD mandates a mechanical modification (per McCauley Service Bulletin No. 116) to specified McCauley propeller governors, affecting aircraft owners/operators, maintenance and overhaul organisations, and parts suppliers. Governors must receive the SB116 modification before being re‑installed after their next reconditioning following 31 August 1979. Modified production and field units are identified by an “A” suffix on the model or serial number, allowing verification by inspection or maintenance records."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification","history":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification/history","analysis":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification/analysis","conflicts":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification/conflicts","importantCases":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification/important-cases","documents":"/api/acts/ad-gov-6-governor-pressure-relief-valve-roll-pin-modification/documents"}}