{"id":"F2006B09951","name":"AD/FK-P/6 Amdt 1 - Diaphragm Fuel Pumps","slug":"ad-fk-p-6-amdt-1-diaphragm-fuel-pumps","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55215,"registerId":"commonwealth-F2006B09951-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/FK-P/6 Amdt 1 - Diaphragm Fuel Pumps","content":"![](image.001.png)\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/FK-P/6 and issues the following AD under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nFranklin Piston Engines\n\nAD/FK-P/6\n\nAmdt 1\n\n  \n\nDiaphragm Fuel Pumps 10/2003 TX\n\nApplicability: All WSK“PZL-Rzeszow” or Franklin manufactured horizontally opposed piston engines incorporating a diaphragm fuel pump.\n\nNote 1: This Directive is not applicable to aircraft with a gravity feed only fuel system.\n\nRequirement: 1. Identify the model and part number of the installed diaphragm fuel pump in accordance with Section I of WSK/Franklin Service Bulletin (SB) Number PZLF/71/2002.\n\n    2. Remove from service, diaphragm fuel pumps identified as model AC4886 or AC Part Number (P/N) 5656774 or PZL P/N 26.11.1710.\n\n    3. Replace the diaphragm pump with a sliding vane pump as detailed in WSK/Franlin SB PZL-F/72A/2002 or SB PZL-F/73A/2002 as applicable.\n\nNote 2: Republic of Poland General Inspectorate of Civil Aviation Airworthiness\n\nDirectives Nr SP-0088-2002-B and Nr SP-0045-2003-B refer.\n\nCompliance: Prior to further flight.\n\nThis Amendment becomes effective on 22 August 2003.\n\nBackground: Amendment 1 of this Directive introduces an approved replacement for the fuel pump.\n\nThis Directive was issued to address a report received by the FAA from the Polish General Inspectorate of Civil Aviation (GICA). The report detailed that there have been several failures of the pump check valves and diaphragms in certain AC4886 diaphragm fuel pumps. Failure of the fuel pump check valves can result in a reduction or complete loss of fuel flow. Failure of the diaphragm may also result in a loss of fuel flow or a fire risk from an external fuel leak.\n\nFranklin Piston Engines\n\nAD/FK-P/6 Amdt 1 (continued)\n\nThe original issue of this Directive became effective on 30 August 2002.\n\n![](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 20 August 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 22 August 2003.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 revokes the original AD and adds an approved replacement option: it specifies exact pump models/part numbers to remove and mandates replacement with a sliding‑vane pump per WSK/Franklin Service Bulletins (Requirement 2–3; Background). The applicability (all WSK/PZL‑Rzeszow or Franklin horizontally opposed piston engines with a diaphragm fuel pump) remains unchanged, but the remedy and approved repair path are newly specified."},"complexity_factors":["Direct operational impact: mandatory removal and replacement prior to further flight creates immediate grounding risk and logistic costs for affected aircraft (Compliance: Prior to further flight).","Identification task: requires checking model and part numbers against Service Bulletin PZLF/71/2002 to determine affected units (Requirement 1).","Specified parts list: only certain part numbers/models are targeted (Requirement 2), so accurate parts management is necessary to avoid unnecessary replacement.","Mandated replacement method: replacement must follow one of two specific service bulletins (PZL‑F/72A/2002 or PZL‑F/73A/2002) which creates dependence on those engineering instructions and parts supply (Requirement 3).","Regulatory pedigree: directive revokes the prior AD and introduces an approved replacement (Background), requiring operators to track amendment status and comply with the updated remedy.","Safety rationale and evidence linkage: directive is based on foreign airworthiness reports (FAA/GICA) of valve and diaphragm failures, so implementation relies on the factual link between those reports and affected installations (Background).","Record and compliance burden: operators must document identification and replacement actions to demonstrate compliance with the AD and referenced service bulletins (Requirement & Compliance)."],"plain_english_summary":"This Airworthiness Directive requires operators of WSK “PZL‑Rzeszow” or Franklin horizontally opposed piston engines with a diaphragm fuel pump to identify installed pump models, remove pumps listed (AC4886 / AC P/N 5656774 / PZL P/N 26.11.1710) and replace them with an approved sliding‑vane pump before next flight. It follows reports of diaphragm and check‑valve failures that can cause loss of fuel flow or external fuel leaks and sets the replacement procedure by reference to specified WSK/Franklin service bulletins."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original safety purpose of the 2002 directive. The only change is adding an approved replacement pump option (sliding vane pump per SB PZL-F/72A/2002 or PZL-F/73A/2002), which is a technical refinement rather than scope expansion."},"complexity_factors":["Very short document (under 500 words)","Only 3 defined part numbers to identify","Simple conditional structure: identify → remove → replace","Single cross-reference to manufacturer service bulletins (SB PZLF/71/2002, PZL-F/72A/2002, PZL-F/73A/2002)","No nested exceptions or complex legal definitions","Clear applicability note excluding gravity-fed systems","Immediate compliance requirement with no phased implementation"],"plain_english_summary":"This airworthiness directive requires immediate replacement of certain faulty diaphragm fuel pumps on WSK \"PZL‑Rzeszow\" or Franklin horizontally opposed piston engines (not affecting gravity‑fed systems). Operators must identify installed pump models, remove the specified defective pumps (including AC4886/AC P/N 5656774/PZL P/N 26.11.1710), and install an approved sliding‑vane replacement before the next flight. Issued after multiple failures that caused fuel starvation and fire risk, the 2003 amendment adds an approved replacement option."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps","history":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps/history","analysis":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps/analysis","conflicts":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps/conflicts","importantCases":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps/important-cases","documents":"/api/acts/ad-fk-p-6-amdt-1-diaphragm-fuel-pumps/documents"}}