{"id":"F2006B09952","name":"AD/FK-P/7 - Interchangeability of Parts","slug":"ad-fk-p-7-interchangeability-of-parts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55216,"registerId":"commonwealth-F2006B09952-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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\nFranklin Piston Engines","sortOrder":0},{"sectionNumber":"AD/FK-P/7 Interchangeability of Parts 1/","sectionType":"part","heading":"AD/FK-P/7 Interchangeability of Parts 1/2003 TX","content":"# AD/FK-P/7 Interchangeability of Parts 1/2003 TX\n\nApplicability: All Frank lin model 6A-350-C1R, C1, C2 and 4A-235-B3, B31, B4 engines. Requirement: Action in accordance with WSK-RZESZOW Service Bulletin PZL-F/69/2002.\n\nNote: Republic of Poland General Inspectorate of Civil Aviation Airworthiness Directive Nr SP-0058-2002-B refers.\n\nCompliance: Before further flight.\n\nThis Airworthiness Directive becomes effective on 29 November 2002.\n\nBackground: There have been occurrences of excessive wear of the drive gears between the oil pump and the camshaft. This is due to different specifications regarding the hardness of the materials used for the manufacture of the gears. More than one manufacturer supplies the gears. Mixing of the gears can cause excessive wear and ultimately lead to the failure of the engine. This Directive addresses the problem by providing an in- service check for engines already fitted with a mixed set of gears, and a requirement for engines needing gears to be replaced at overhaul to have any gear replacements done in matched pairs.\n\n![](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 26 November 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 29 November 2002.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow safety directive addressing a specific mechanical defect in specific engine models. It has not expanded beyond its original purpose of preventing gear wear failures."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined engine model ranges in applicability section","Single requirement referencing an external service bulletin rather than detailing technical steps","No nested exceptions or conditional logic","Simple compliance trigger: 'before further flight'","No cross-references to other legislation beyond a single note about a Polish airworthiness directive"],"plain_english_summary":"This CASA Airworthiness Directive mandates immediate compliance with WSK‑RZESZOW Service Bulletin PZL‑F/69/2002 for certain Franklin piston engines after discovery that mismatched oil‑pump/camshaft drive gears (from different manufacturers with different hardness) wear rapidly and can cause in‑flight engine failure. It affects operators of Franklin 6A‑350‑C1R/C1/C2 and 4A‑235‑B3/B31/B4 engines: inspect in‑service engines for mixed gears and ensure overhauled engines receive matched‑pair gears."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD’s scope matches the problem described in its background: it targets the specified Franklin engine models, requires an in‑service check where mixed gear sets may exist, and mandates matched‑pair gear replacement at overhaul. There is no indication in the text that the instrument expands beyond addressing excessive drive‑gear wear caused by mixing gears of differing hardness."},"complexity_factors":["Narrow technical scope — applies only to specific Franklin engine models (6A‑350‑C1R/C1/C2 and 4A‑235‑B3/B31/B4) which limits regulatory breadth.","Immediate compliance requirement — ‘‘Before further flight’’ creates urgent operational and scheduling pressure for operators.","External technical dependency — mandates actions in accordance with WSK‑RZESZOW Service Bulletin PZL‑F/69/2002, so the AD’s actionable content is contained in an external document.","Supply‑chain implication — notes multiple gear manufacturers and requires matched‑pair replacements at overhaul, which can constrain parts sourcing and inventory practices.","Safety‑critical maintenance — inspection and replacement decisions affect engine reliability and flight safety, increasing regulatory and technical scrutiny.","Cross‑jurisdictional reference — cites a Republic of Poland airworthiness directive, introducing reliance on foreign technical findings and standards."],"plain_english_summary":"This Airworthiness Directive requires owners and maintenance organisations of specified Franklin piston engines to follow WSK‑RZESZOW Service Bulletin PZL‑F/69/2002: inspect for mixed oil‑pump-to‑camshaft drive gears and, when replacing gears at overhaul, install matched pairs. Compliance is mandatory before further flight.\n\nIt affects engine owners, mechanics and parts suppliers who bear inspection and replacement costs. CASA says the rule responds to excessive gear wear caused by mixing gears from different manufacturers with differing material hardness."},"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-7-interchangeability-of-parts","history":"/api/acts/ad-fk-p-7-interchangeability-of-parts/history","analysis":"/api/acts/ad-fk-p-7-interchangeability-of-parts/analysis","conflicts":"/api/acts/ad-fk-p-7-interchangeability-of-parts/conflicts","importantCases":"/api/acts/ad-fk-p-7-interchangeability-of-parts/important-cases","documents":"/api/acts/ad-fk-p-7-interchangeability-of-parts/documents"}}