{"id":"F2006B09895","name":"AD/F50/66 - Lavatory Pump and Filter Assembly Electrical Grounding","slug":"ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55048,"registerId":"commonwealth-F2006B09895-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/66 - Lavatory Pump and Filter Assembly Electrical Grounding","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)  \nFokker F50 (F27 Mk 50) Series Aeroplanes\n\nAD/F50/66 Lavatory Pump and Filter Assembly Electrical Grounding\n\n  \n12/94\n\nApplicability: Model F27 Mk50 aircraft serial numbers 20103 through 20226 inclusive, 20270 through 20292 inclusive, 20296 through 20304 inclusive, 20306, 20307, 20309,\n\n20310 and 20312.\n\nRequirement: Action in accordance with accomplishment instructions of Fokker Service Bulletin F50-25-046 Revision 1 dated 5 August 1994.\n\nNote: RLD AD 94-129 (A) dated 31 August 1994 refers.\n\nCompliance: Prior to 10 May 1995.\n\nBackground: The Lavatory Pump and Filter Assembly is driven by a 115V AC motor and the metal toilet bowl is connected to the housing of the electric motor.\n\nHowever, the motor housing is not connected to an effective ground. Consequently, should a failure of the electric motor occur, the toilet bowl may carry a high voltage. This Directive requires the installation of an electrical ground connection.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD applies to the specific aircraft serial numbers listed and requires installation of an electrical ground per the Fokker service bulletin by a fixed date. The text supplied does not indicate any change to that scope or to the set of affected aircraft; it references a related RLD AD but does not state that the applicability or required action has been expanded or narrowed from a prior instrument. (Applicability; Requirement; Note)"},"complexity_factors":["Narrow, enumerated applicability by serial number (Applicability)","Single remedial technical action required (installation of an electrical ground) referenced to one manufacturer service bulletin (Requirement)","Clear single compliance deadline (Compliance)","Reliance on a manufacturer's service bulletin for detailed instructions (Requirement)","Regulatory cross-reference to a related RLD AD (Note)"],"plain_english_summary":"What this instrument changes (mechanically)\n\n- It requires installation of an electrical ground connection between the lavatory pump/electric-motor housing and the aircraft grounding system on specified Fokker F50 (F27 Mk 50) aeroplanes. The work must be carried out in accordance with the accomplishment instructions of Fokker Service Bulletin F50-25-046 Revision 1 dated 5 August 1994. (Requirement)\n\nWho this affects and when it must be done\n\n- The directive applies to Fokker F27 Mk50 aeroplanes with the serial numbers listed in the AD. (Applicability)\n- Operators of those aircraft must complete the specified installation prior to 10 May 1995. (Compliance)\n\nWhy the Directive was issued (the stated safety problem)\n\n- The AD records that the lavatory pump is driven by a 115 V AC motor whose metal housing is connected to the toilet bowl, but the motor housing was not connected to an effective electrical ground. Consequently, a motor failure could leave the toilet bowl at high voltage. To address that hazard, the AD requires installation of an electrical ground connection. (Background)\n\nHow it works in practice (who pays, who decides, and what behaviour changes)\n\n- The Civil Aviation Safety Authority (as issuer of the AD) requires the operator of each affected aircraft to carry out the grounding modification by following the Fokker service bulletin. (Requirement)\n- Practically, an operator must identify aircraft that fall within the serial-number list and schedule maintenance to install the ground connection before the compliance date. (Applicability; Compliance; Requirement)\n\nAssessment of incentives, costs and trade-offs (source-grounded)\n\n- The stated benefit is reduction of an electric-shock or electrocution hazard if the motor fails, achieved by adding an effective ground connection. (Background)\n- The AD imposes a compliance obligation on operators of the listed aircraft to perform the modification per the manufacturer’s instructions. The AD itself does not detail parts, labour hours, or direct costs; those are determined by following the Service Bulletin. (Requirement)\n- The obligation is narrowly targeted by serial number, so the direct compliance burden is concentrated on operators who own or manage those specific aircraft. (Applicability)\n- The AD sets a single, firm compliance deadline, which creates a time-limited implementation requirement and the usual operational trade-off between scheduling maintenance and keeping the aircraft in service. (Compliance)\n\nImplementation risk, discretion and administrative structure (source-grounded)\n\n- The AD specifies the method of compliance by reference to the manufacturer’s service bulletin; it does not leave broad discretionary choices about how to fix the problem. Compliance therefore requires following the Bulletin’s instructions. (Requirement)\n- The AD cross-references a related RLD AD (RLD AD 94-129 (A)). The AD does not specify any financial assistance, exemptions, or alternative compliance means in the text provided. (Note)\n\nMarket and operational effects (source-grounded, limited by what the AD states)\n\n- The directive alters a maintenance requirement for operators of the listed serial-number aircraft. It does not change ownership, market entry rules, pricing regulation, or broader competition rules as stated in the AD. The economic effect within the AD is limited to the compliance obligation on the specified operators. (Applicability; Requirement)\n\nSections cited: Applicability; Requirement (Fokker Service Bulletin F50-25-046 Rev 1, 5 Aug 1994); Compliance (prior to 10 May 1995); Background; Note (RLD AD 94-129 (A))."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific electrical hazard in a specific aircraft type. It has not expanded beyond its original purpose of mandating a grounding modification."},"complexity_factors":["Single, specific technical requirement (install ground connection)","Only 4 defined applicability criteria (aircraft model and serial number ranges)","No nested exceptions or conditional logic","No cross-references to other legislation beyond a single note referencing a Dutch aviation authority directive","Clear, single compliance deadline","Background explanation provided in plain language"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners or operators of certain Fokker F50 aeroplanes to install an electrical ground connection on the lavatory (toilet) pump and filter assembly.\n\n**Why it matters:** The toilet bowl in these planes is connected to an electric motor that runs the pump. If that motor fails, the toilet bowl could become \"live\" with 115 volts of electricity — a serious electrocution risk for anyone using the toilet. This directive fixes that hazard by ensuring the motor housing is properly grounded (connected to the aircraft's electrical earth, so any stray current safely dissipates rather than shocking passengers or crew).\n\n**Who must comply:** Anyone operating Fokker F50 aircraft with specific serial numbers listed (roughly 100+ aircraft built between certain production runs).\n\n**What they must do:** Follow the exact repair instructions in Fokker Service Bulletin F50-25-046 Revision 1 (dated 5 August 1994) — essentially a manufacturer-issued repair manual for this specific fix.\n\n**Deadline:** The work had to be completed before 10 May 1995."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding","history":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding/history","analysis":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding/analysis","conflicts":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding/conflicts","importantCases":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding/important-cases","documents":"/api/acts/ad-f50-66-lavatory-pump-and-filter-assembly-electrical-grounding/documents"}}