{"id":"F2010L01932","name":"AD/PW500/3 - Hydro-mechanical Fuel Control Units","slug":"ad-pw500-3-hydro-mechanical-fuel-control-units","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":124372,"registerId":"commonwealth-F2010L01932-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Canada Turbine Engines","sectionType":"division","heading":"Pratt and Whitney Canada Turbine Engines - PW500 Series","content":"### Pratt and Whitney Canada Turbine Engines - PW500 Series\n\n| AD/PW500/3 | Hydro-mechanical Fuel Control Units | 14/2010 |\n| ---------- | ----------------------------------- | ------- |\n\n| Applicability: | Pratt & Whitney Canada PW535A engines prior to serial number DC0241 with hydro-mechanical fuel control (HFC) P/N 819735-4, 819735-5, or 819735-6.                                                                                                                                                                                                                                     |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Unless previously accomplished, action in accordance with the requirements of Transport Canada AD CF-2004-28.Note: P&WC ASB A30257R1 and P&WC Engine Maintenance Manual 3044952 R14 refer.                                                                                                                                                                                            |\n| Compliance:    | For installed HFC units, within 50 hours after the effective date of this AD.For HFC units not installed, at time of installation.                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 16 July 2010.                                                                                                                                                                                                                                                                                                                       |\n| Background:    | Incidents of PW535A engines experiencing lack of response to the power lever input due to an incorrect adjustment of the HFC ratio unit setscrew during engine acceleration time setting has been reported. As a result, this AD requires inspection and verification of the proper adjustment of the HFC ratio unit setscrew, and implementation of correct installation procedures. |\n\n![](image.001.png)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n5 July 2010","sortOrder":0},{"sectionNumber":"AD/PW500/3","sectionType":"part","heading":"AD/PW500/3","content":"## AD/PW500/3","sortOrder":1},{"sectionNumber":"Hydro-mechanical Fuel Control Units","sectionType":"part","heading":"Hydro-mechanical Fuel Control Units","content":"## Hydro-mechanical Fuel Control Units","sortOrder":2},{"sectionNumber":"14/2010","sectionType":"part","heading":"14/2010","content":"## 14/2010","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD implements the Transport Canada action (AD CF-2004-28) for a defined subset of PW535A engines and HFC part numbers and sets compliance timing; it does not expand applicability beyond the specified serial numbers and part numbers, nor add new corrective actions beyond inspection/verification and installation procedure requirements (Requirement; Applicability)."},"complexity_factors":["Narrow technical scope: applies only to PW535A engines before serial DC0241 with specified HFC P/Ns (Applicability).","Dependence on external documents: compliance is via Transport Canada AD CF-2004-28 and referenced P&WC service material (Requirement; Note).","Short compliance timing: 50 flight hours for installed units and immediate check at installation increases scheduling pressure (Compliance).","Technical work: requires accurate mechanical adjustment verification of the HFC ratio‑unit setscrew, requiring qualified maintenance personnel (Background).","Conditional phrasing: 'unless previously accomplished' requires records checks to confirm prior compliance (Requirement).","Regulatory enforcement: CASA issued the directive with an effective date, creating a legal compliance obligation for operators (Compliance; effective date)."],"plain_english_summary":"This Airworthiness Directive requires inspection and verification of the hydro-mechanical fuel control (HFC) ratio‑unit setscrew adjustment and adoption of correct installation procedures for Pratt & Whitney Canada PW535A engines (serials before DC0241) fitted with HFC P/N 819735-4, -5 or -6 (Applicability; Requirement). Operators and maintenance organisations must carry out the check within 50 flight hours if the unit is installed, or at installation for spare units; the operator bears the labour and compliance burden and CASA enforces the requirement (Compliance)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific mechanical defect in a specific engine model. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined part numbers and 1 serial number cutoff to identify affected equipment","Single compliance pathway with only two timing scenarios (installed vs. uninstalled)","No nested exceptions or conditional logic — compliance is mandatory unless already done","Cross-references only 2 external technical documents (Canadian AD and manufacturer service bulletins)","No interpretation section or defined terms"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Pratt & Whitney Canada PW535A engines (serials before DC0241) with fuel control units P/N 819735-4/5/6 to inspect and correct the hydro‑mechanical fuel control setscrew adjustment that can make the engine unresponsive to the power lever. Inspections must be done within 50 flight hours after 16 July 2010 for installed units, and shelf units must be checked before installation, following Transport Canada and PWC repair procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units","history":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units/history","analysis":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units/analysis","conflicts":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units/conflicts","importantCases":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units/important-cases","documents":"/api/acts/ad-pw500-3-hydro-mechanical-fuel-control-units/documents"}}