{"id":"F2006B11253","name":"AD/M20/48 - M20R Exhaust System","slug":"ad-m20-48-m20r-exhaust-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57022,"registerId":"commonwealth-F2006B11253-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/M20/48 - M20R Exhaust System","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nMooney M20 Series Aeroplanes\n\nAD/M20/48 M20R Exhaust System 7/95\n\nApplicability: M20R aircraft, as listed by serial number in Mooney Aircraft Corporation Service Bulletin M20-257 Revision B, not incorporating an improved exhaust system installed in accordance with Mooney Aircraft Corporation Retrofit Kit Instructions 940095-501-1.\n\nRequirement: Action in accordance with Mooney Aircraft Corporation Service Bulletin M20-257 Revision B.\n\nNote: FAA Airworthiness Directive 95-07-04 refers.\n\nCompliance: Effective 22 June 1995; within 5 hours time in service and thereafter at intervals not to exceed 5 hours time in service.\n\nNote: The replacement of the exhaust system in accordance with Mooney Aircraft Corporation Retrofit Kit Instructions 940095-501-1 is the terminating action for the requirements of this Directive.\n\nBackground: This Directive has been issued to require a repetitive inspection of the exhaust system for evidence of cracks. The requirement follows advice of thirteen reports of exhaust system cracks in Mooney M20R aircraft. Of concern, cracks have been found in aircraft with aircraft time in service as low as 8 hours.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope — addressing a specific safety defect in a specific aircraft model's exhaust system. The scope has not expanded beyond the original safety concern."},"complexity_factors":["Single, specific aircraft model (Mooney M20R) with clear serial number applicability","Only one substantive requirement: repetitive inspection per manufacturer service bulletin","Simple compliance structure: initial 5-hour deadline, then recurring 5-hour intervals","Single terminating action clearly identified (retrofit kit installation)","No nested exceptions, conditional logic, or extensive cross-referencing beyond the service bulletin and FAA directive reference","Background section provides clear rationale without legal obfuscation"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners/operators of certain Mooney M20R aircraft (per M20‑257 Rev B serials) to inspect the exhaust system for cracks within 5 flight hours of 22 June 1995 and then every 5 flight hours thereafter unless the improved exhaust retrofit kit is installed as terminating action. Thirteen crack reports, some at only 8 flight hours, prompted the rule to prevent carbon monoxide leaks or catastrophic engine failure."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The Directive implements repetitive exhaust inspections for the listed M20R aircraft until the retrofit is installed; that is consistent with the instrument's stated purpose. The Background cites 13 reports of cracks, including occurrences as low as 8 hours TIS, which the Directive addresses by requiring very frequent inspections or the retrofit terminating action."},"complexity_factors":["Narrow applicability tied to serial numbers listed in an external Mooney Service Bulletin (M20-257 Rev B)","Very short, repeating compliance interval (every 5 hours TIS)","Indefinite repetition until a specified terminating action (Retrofit Kit 940095-501-1) is installed","Mandate references and relies on external documents (Mooney Service Bulletin and Retrofit Kit Instructions)","Cross-reference to FAA Airworthiness Directive (95-07-04) adds an external compliance context","Regulatory enforcement by CASA (Civil Aviation Safety Authority) is implicit in the Directive"],"plain_english_summary":"This Airworthiness Directive requires operators of certain Mooney M20R aeroplanes (serial numbers listed in Mooney Service Bulletin M20-257 Rev B) to inspect the exhaust for cracks within 5 hours time-in-service and every 5 hours thereafter, until the improved exhaust from Retrofit Kit 940095-501-1 is fitted. The Civil Aviation Safety Authority enforces the requirement; operators bear the cost and must either perform very frequent inspections or install the terminating retrofit."}},"importantCases":[],"_links":{"self":"/api/acts/ad-m20-48-m20r-exhaust-system","history":"/api/acts/ad-m20-48-m20r-exhaust-system/history","analysis":"/api/acts/ad-m20-48-m20r-exhaust-system/analysis","conflicts":"/api/acts/ad-m20-48-m20r-exhaust-system/conflicts","importantCases":"/api/acts/ad-m20-48-m20r-exhaust-system/important-cases","documents":"/api/acts/ad-m20-48-m20r-exhaust-system/documents"}}