{"id":"F2006B11243","name":"AD/M20/39 Amdt 1 - Fuel Filter Assembly","slug":"ad-m20-39-amdt-1-fuel-filter-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56963,"registerId":"commonwealth-F2006B11243-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/M20/39 Amdt 1 - Fuel Filter Assembly","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/M20/39\n\nAmdt 1\n\n  \nFuel Filter Assembly 8/94\n\nApplicability: Aircraft model M20E S/N 101 and subsequent, M20F S/N 660002 and subsequent, M20J S/N 24-0002 through 24-1030 inclusive fitted with Dukes Inc. auxiliary fuel pump incorporating carbon vanes.\n\nRequirement: Unless previously carried out action in accordance with Mooney SB M20-222B. If carbon vanes have been replaced with nylatron vanes in accordance with Dukes Inc Mandatory Service Bulletin No 0002 dated 15 June 1993 the filter cartridge need not be installed in the filter housing if the housing is retained.\n\nNote: FAA AD 80-13-02 amdt 39-3791 refers.\n\nCompliance: By 30 August 1994.\n\nBackground: In the event of internal failure in the auxiliary fuel pump an inline fuel filter is installed to prevent debris damaging the engine driven pump.\n\nThis amendment raised to clarify the filter cartridge installation requirements.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment clarifies the installation requirement for the filter cartridge by specifying that, where Dukes Inc. Mandatory Service Bulletin No 0002 (15 June 1993) has been followed to replace carbon vanes with nylatron vanes and the filter housing is retained, the filter cartridge need not be installed. The change is limited to clarifying and specifying an alternative compliance path rather than expanding the set of affected aircraft. (Requirement, This amendment)"},"complexity_factors":["Serial-numbered applicability (specific M20 submodels and S/N ranges) requires operators to check records before acting (Applicability).","Conditional requirement structure: mandatory action unless previously done or unless an alternative vane-replacement path has been followed (Requirement).","Cross-references to two mandatory service bulletins and an FAA AD increase procedural steps and document-following (Requirement, Note).","A firm compliance deadline concentrates workload and creates scheduling pressure for operators and maintenance providers (Compliance).","Technical specificity about pump internals (carbon vs nylatron vanes) requires specialist maintenance capability and parts availability (Requirement, Background)."],"plain_english_summary":"### What this directive requires, in plain terms\n\n- It applies to certain Mooney M20 series aircraft: M20E (serial number 101 and up), M20F (S/N 660002 and up) and M20J (S/N 24-0002 through 24-1030) when those aeroplanes are fitted with a Dukes Inc. auxiliary fuel pump that uses carbon vanes. (Applicability)\n\n- The directive requires operators to carry out the actions described in Mooney Service Bulletin M20-222B unless those actions have already been completed. As an explicit alternative, if the pump’s carbon vanes have been replaced with nylatron vanes in accordance with Dukes Inc. Mandatory Service Bulletin No 0002 (dated 15 June 1993), then a filter cartridge does not have to be installed in the filter housing provided the housing itself is kept. (Requirement)\n\n- The deadline to comply is 30 August 1994. (Compliance)\n\n- The stated technical purpose is to prevent debris from an internal failure of the auxiliary fuel pump from damaging the engine-driven fuel pump; the filter is the protective measure. (Background)\n\n- This amendment clarifies when the filter cartridge must be installed and when it may be omitted because of an approved vane replacement. (This amendment)\n\n\nWho pays and who decides\n\n- Aircraft owners/operators are responsible for meeting the directive by the compliance date; they pay for parts, labour and any inspection or modification work (Requirement, Compliance).\n\n- The Civil Aviation Safety Authority issues the directive; compliance choices for owners are limited to following the Mooney service bulletin or carrying out the specified Dukes vane replacement. (Applicability, Requirement)\n\n\nMechanics, incentives and trade-offs\n\n- Mechanical choice offered: install the inline filter cartridge described in Mooney SB M20-222B, or replace carbon vanes with nylatron vanes per Dukes Mandatory SB No 0002 and retain the existing filter housing without fitting the cartridge. That replacement substitutes a parts change for installing the cartridge. (Requirement)\n\n- Incentives: an operator may avoid installing the cartridge (and the associated immediate parts/labour) by performing the vane replacement that the Dukes mandatory bulletin prescribes. The directive therefore creates a practical substitution between two compliance actions. (Requirement)\n\n- Costs and compliance burden: operators must verify serial-number applicability, inspect the auxiliary pump, and undertake either the filter installation or vane replacement. Costs are incurred in parts, labour, and aircraft downtime up to the compliance date. (Applicability, Requirement, Compliance)\n\n- Implementation risk and discretion: the AD prescribes the required actions and deadline; operators have limited discretion beyond selecting the specified compliance path. The amendment narrows uncertainty by clarifying when the cartridge need not be installed. (Requirement, This amendment)\n\n\nEffects on private choice and market participants\n\n- The directive affects owners/operators of the specified M20 aircraft and aftermarket/maintenance providers who perform the work. It does not directly change operator rights beyond imposing the compliance obligation and offering the stated alternative method. (Applicability, Requirement)\n\n- Substitution effects are concrete: replacing vanes (a change to the pump internals) replaces the need to install the cartridge in the filter housing, provided the housing is retained. This alters which parts and labour are demanded from maintenance suppliers. (Requirement)\n\n\nCross-references and notices\n\n- The document notes a related FAA airworthiness directive (FAA AD 80-13-02 amdt 39-3791) and references two service bulletins (Mooney SB M20-222B and Dukes Mandatory SB No 0002). Operators must follow the specified service-bulletin procedures to meet the AD’s conditions. (Note, Requirement)\n\n\nBottom line\n\n- The AD mandates a protective action against debris from auxiliary fuel-pump failure for specific Mooney M20 aeroplanes by a set date. Operators can comply either by installing a filter cartridge per Mooney SB M20-222B or, alternatively, by replacing carbon vanes with nylatron vanes per Dukes SB No 0002 and keeping the existing housing. The amendment’s stated effect is to clarify that alternative clearly. (Requirement, Background, This amendment)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a narrow, technical safety directive addressing a specific mechanical failure mode in specific aircraft. The amendment merely clarifies installation requirements without expanding the scope beyond the original fuel pump debris protection purpose."},"complexity_factors":["Short, single-purpose directive (approximately 150 words)","Limited applicability: 3 specific aircraft models with serial number ranges and one specific pump type","One conditional exception (nylatron vane replacement) with nested condition (housing must be retained)","References to external documents: 2 service bulletins (Mooney SB M20-222B, Dukes Inc. MSB 0002) and 1 FAA AD (80-13-02)","No defined terms section; plain language used throughout","Single compliance date with no phased or alternative compliance options"],"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) that requires specific maintenance actions on certain aircraft.\n\n**What it does:** It orders owners and operators of specific **Mooney M20 series aeroplanes** (small, single-engine aircraft) to install a fuel filter assembly in the fuel line. This filter catches debris if the auxiliary fuel pump fails internally, preventing that debris from damaging the engine's main fuel pump.\n\n**Who it affects:** Owners and operators of:\n- Mooney M20E aircraft (serial number 101 and later)\n- Mooney M20F aircraft (serial number 660002 and later)  \n- Mooney M20J aircraft (serial numbers 24-0002 through 24-1030)\n\n**Only if** these aircraft are fitted with a **Dukes Inc. auxiliary fuel pump that uses carbon vanes** (small sliding pieces inside the pump).\n\n**The specific requirement:**\n- Follow the instructions in **Mooney Service Bulletin M20-222B** (a manufacturer's technical notice) to install the fuel filter.\n- **Exception:** If the carbon vanes have already been replaced with **nylatron vanes** (a different material) following Dukes Inc. Service Bulletin No. 0002 (dated 15 June 1993), then you don't need to install the filter cartridge — but you must keep the filter housing in place.\n\n**Why it matters:** Without this filter, carbon debris from a failing auxiliary pump could flow into and destroy the engine-driven fuel pump, potentially causing **engine failure in flight**.\n\n**Compliance deadline:** The work had to be completed by **30 August 1994**.\n\n**What changed in this amendment:** The update simply clarifies when the filter cartridge must actually be installed versus when the housing alone is sufficient (the nylatron vane exception)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly","history":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly/history","analysis":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly/analysis","conflicts":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly/conflicts","importantCases":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly/important-cases","documents":"/api/acts/ad-m20-39-amdt-1-fuel-filter-assembly/documents"}}