{"id":"F2008L02878","name":"AD/JT15D/10 - Engine P3 Compressor Delivery Tube","slug":"ad-jt15d-10-engine-p3-compressor-delivery-tube","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74761,"registerId":"commonwealth-F2008L02878-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Canada Turbine Engines","sectionType":"division","heading":"Pratt and Whitney Canada Turbine Engines - JT15D Series","content":"### Pratt and Whitney Canada Turbine Engines - JT15D Series\n\n| AD/JT15D/10 | Engine P3 Compressor Delivery Tube | 9/2008 |\n| ----------- | ---------------------------------- | ------ |\n\n| Applicability: | Pratt & Whitney Canada (P&WC):JT15D-5 engines which are before and include serial number PCE-100411; andJT15D-5 engines which are before and include serial number PCE-JA0818; andAll JT15D-5B engines; andAll JT15D-5F engines; andJT15D-5R engines which are before and include serial number PCE-JG0104; andAll JT15D-5 engines converted to model JT15D-5R by incorporation of P&WC Service Bulletin (SB) 7605.                                                                                                       |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Unless previously accomplished, incorporate P&WC Alert Service Bulletin (ASB) number A7611 Revision No. 1 dated 16 June 2008, or later revisions approved by Transport Canada.Compliance with P&WC ASB A7611 dated 26 March 2008 prior to the effective date of this directive satisfies the corrective actions requirement of this directive.Note: Transport Canada AD CF-2008-23 dated 27 June 2008 refers.                                                                                                             |\n| Compliance:    | Within 200 flight hours after the effective date of this directive, or before31 December 2008, whichever occurs first.                                                                                                                                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 28 August 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background:    | There have been several reported incidents of high altitude, dual engine flameout on JT15D-5 engines powered aircraft operating in certain meteorological conditions. Subsequent to the investigation of incidents, review of the engine design has revealed that the Fuel Control Hydro Mechanical Unit (HMU) P3 servo can be exposed to excessive moisture and freezing. To preclude P3 servo freezing, P&WC has issued JT15D ASB A7611 to re-route compressor delivery air to the HMU and improve moisture separation. |\n\n|     | Considering the potentially hazardous consequence of possible in-flight dual engine flameout, this AD is issued to mandate the incorporation of P&WC ASB A7611 to the affected JT15D-5 engines, in order to minimize the possibility of this hazard. |\n| --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n16 July 2008","sortOrder":0},{"sectionNumber":"AD/JT15D/10","sectionType":"part","heading":"AD/JT15D/10","content":"## AD/JT15D/10","sortOrder":1},{"sectionNumber":"Engine P3 Compressor Delivery Tube","sectionType":"part","heading":"Engine P3 Compressor Delivery Tube","content":"## Engine P3 Compressor Delivery Tube","sortOrder":2},{"sectionNumber":"9/2008","sectionType":"part","heading":"9/2008","content":"## 9/2008","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The instrument does not amend or expand scope beyond its stated purpose. It targets specified JT15D engine models and serial ranges (including certain conversions) to mandate incorporation of ASB A7611 to mitigate P3 servo freezing and related dual‑engine flameout risk (Applicability, Requirement, Background)."},"complexity_factors":["Applicability detail: multiple engine models with specific serial‑number cut‑offs and conversion exceptions increase identification and compliance steps (Applicability).","External‑document dependency: mandated incorporation of P&WC ASB A7611 Rev No.1 or later approved revisions means operators must obtain and follow an external service bulletin (Requirement).","Time pressure and scheduling: compliance required within 200 flight hours or before 31 December 2008, whichever first, creating a short compliance window (Compliance).","Safety urgency and technical work: the action is a physical modification to reroute compressor air and improve moisture separation, imposing maintenance planning, parts and labour demands on operators (Requirement / Background).","Regulatory cross‑references: the directive notes Transport Canada AD CF‑2008‑23, adding interjurisdictional coordination for operators and maintainers (Requirement / Note).","Administrative clarity: effective date and delegated issuance are explicit (effective 28 August 2008; delegate named), but the AD does not state costs or approved suppliers, leaving operational and budgetary discretion to operators (Compliance / signature)."],"plain_english_summary":"This directive requires aircraft operators to install Pratt & Whitney Canada Alert Service Bulletin A7611 (or later approved revisions) to reroute P3 compressor delivery air and improve moisture separation on specified JT15D-5, -5B, -5F and certain -5R engines. It applies to engines listed by serial-number cut‑offs and conversion status, must be done within 200 flight hours or by 31 December 2008, and is intended to reduce the risk of high‑altitude dual‑engine flameout caused by P3 servo icing."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific safety-critical defect in a defined engine population. The scope remains precisely limited to the moisture/freezing issue in the P3 compressor delivery system as originally identified."},"complexity_factors":["Single, specific technical requirement with clear alternative compliance path (earlier service bulletin version)","Well-defined applicability using specific engine model numbers and serial number ranges","Simple compliance deadline structure (flight hours OR calendar date, whichever first)","No nested exceptions or conditional logic beyond the 'unless previously accomplished' exemption","Single cross-reference to Transport Canada AD for administrative alignment","Technical terminology present but explained through context (P3 servo, HMU, flameout)"],"plain_english_summary":"This CASA Airworthiness Directive mandates installation of a modified compressor delivery tube on certain Pratt & Whitney Canada JT15D-5/5B/5F/5R engines to reroute air and improve moisture separation, preventing fuel-control icing that led to dual engine flameouts at altitude. \n\nIt affects owners/operators of the specified JT15D serial-numbered engines (and certain conversions) and requires compliance with the Pratt & Whitney Alert Service Bulletin within 200 flight hours or by 31 December 2008; AD effective 28 August 2008."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube","history":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube/history","analysis":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube/analysis","conflicts":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube/conflicts","importantCases":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube/important-cases","documents":"/api/acts/ad-jt15d-10-engine-p3-compressor-delivery-tube/documents"}}