{"id":"F2009L01521","name":"AD/J4100/26 - Propellers - Propeller Speed Warning System - Installation","slug":"ad-j4100-26-propellers-propeller-speed-warning-system-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78164,"registerId":"commonwealth-F2009L01521-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"BAe Systems (Operations) Jetstream 4100 ","sectionType":"division","heading":"BAe Systems (Operations) Jetstream 4100 Series Aeroplanes","content":"### BAe Systems (Operations) Jetstream 4100 Series Aeroplanes\n\n| AD/J4100/26 | Propellers - Propeller SpeedWarning System - Installation | 5/2009 |\n| ----------- | --------------------------------------------------------- | ------ |\n\n| Applicability: | Jetstream Aircraft Ltd, British Aerospace Regional Aircraft Ltd, British Aerospace (Operations) Ltd and British Aerospace (Commercial Aircraft) Ltd Jetstream 4100 aircraft, all models, all serial numbers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. Replace the existing Propeller Limitations Placard in the cockpit in accordance with BAE Systems (Operations) Ltd Service Bulletin (SB) J41-11-027 and ensure that the AFM contains General Amendment G12 and Advance Amendment Bulletin No. 13.2. Install a Propeller Speed Warning System (modification JM41674) in accordance with Section 2 of BAE Systems (Operations) Ltd ACIB J41-61-014 and ensure that the AFM contains Particular Amendment P111.3. Remove the placard and AFM Advance Amendment Bulletin No. 13 as introduced by Requirement 1 of this AD.The use of later approved revisions of the referenced documents is acceptable for compliance with the requirements of this AD.Note: EASA AD 2009-0038 dated 18 February 2009 refers. |\n| Compliance:    | For Requirement 1 - Within 30 days after the effective date of this AD, unless previously accomplished.For Requirement 2 - Within the next 6 months after the effective date of this AD.For Requirement 3 - After modification of an aircraft as Detailed in Requirement 2 of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n|                | This Airworthiness Directive becomes effective on 7 May 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | During ground manoeuvring, prolonged operation with either engine in the restricted range between 82% and 90% RPM will result in damage to the propeller assembly that could eventually result in the release of a propeller blade.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n\n|     | BAE Systems has now developed a Propeller Speed Warning System, embodiment of which will allow taxiing with the condition lever at TAXI, through the introduction of a revised Flight Manual Limitation.This AD requires the installation of a Propeller Speed Warning System. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n27 March 2009","sortOrder":0},{"sectionNumber":"AD/J4100/26","sectionType":"part","heading":"AD/J4100/26","content":"## AD/J4100/26","sortOrder":1},{"sectionNumber":"Propellers - Propeller SpeedWarning Syst","sectionType":"part","heading":"Propellers - Propeller SpeedWarning System - Installation","content":"## Propellers \\- Propeller Speed  \nWarning System \\- Installation","sortOrder":2},{"sectionNumber":"5/2009","sectionType":"part","heading":"5/2009","content":"## 5/2009","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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope. It addresses a specific mechanical safety issue (propeller damage during ground operations) with a targeted technical solution (warning system installation). The scope has not expanded beyond this original safety purpose."},"complexity_factors":["Short, single-purpose directive with only 3 sequential requirements","Minimal defined terms (only standard aviation acronyms like AFM, SB, ACIB, RPM)","Clear compliance deadlines with simple time-based triggers (30 days, 6 months, 'after modification')","No nested exceptions or conditional logic — requirements apply uniformly to all affected aircraft","References to external technical documents (Service Bulletin, ACIB) but these are standard aviation practice and clearly identified","Straightforward cause-and-effect: identified safety risk → mandated technical fix"],"plain_english_summary":"This CASA Airworthiness Directive requires all BAe Jetstream 4100 operators to install a Propeller Speed Warning System to alert pilots if propeller RPM enters a dangerous taxiing range that could lead to blade failure.  \n\nOperators must update the AFM and fit a temporary cockpit placard within 30 days, install the warning-system hardware within six months, and remove the temporary placard after installation. This is mandatory for all Jetstream 4100 aircraft."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to all Jetstream 4100 aircraft and mandates placard replacement, AFM amendments and installation of a warning system as described. There is no language in the instrument indicating an expansion or narrowing of the affected fleet or the required corrective action beyond what the AD states (Applicability; Requirement)."},"complexity_factors":["Applicability to every Jetstream 4100 aircraft, all models and serial numbers (Applicability).","Technical installation required: Propeller Speed Warning System, modification JM41674 (Requirement; references SB J41-11-027 and ACIB J41-61-014).","Mandatory AFM amendments and placard changes create procedural compliance steps for operators (Requirement).","Short compliance windows increase logistics pressure: 30 days for placard, 6 months for system installation (Compliance).","References and acceptance of later approved revisions mean compliance depends on following external service documents and version control (Requirement note).","Safety rationale is specific and operational (risk of blade release when operating 82–90% RPM), tying technical mitigation to an acute hazard (Background)."],"plain_english_summary":"Requires all Jetstream 4100 aircraft to have the cockpit propeller limitations placard replaced, a Propeller Speed Warning System (mod JM41674) installed, and the Aircraft Flight Manual (AFM) updated. Operators must carry out the changes within short statutory deadlines (30 days for the placard, 6 months for the warning‑system fit) to reduce the risk of propeller damage from prolonged operation in the restricted 82–90% RPM range that could lead to blade release."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation","history":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation/history","analysis":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation/analysis","conflicts":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation/conflicts","importantCases":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation/important-cases","documents":"/api/acts/ad-j4100-26-propellers-propeller-speed-warning-system-installation/documents"}}