{"id":"F2021L01103","name":"AD/GBK 117/7 Amdt 1 Retrofit of Engine Overspeed Controller","slug":"ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":102019,"registerId":"commonwealth-F2021L01103-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Helicopters Deutschland (Eurocopt","sectionType":"part","heading":"Airbus Helicopters Deutschland (Eurocopter) MBB-BK 117 Series Helicopters","content":"# Airbus Helicopters Deutschland (Eurocopter) MBB-BK 117 Series Helicopters\n\n| AD/GBK 117/7 Amdt 1 | Retrofit of Engine Overspeed Controller | 16/2021 |\n| ------------------- | --------------------------------------- | ------- |\n\n| Applicability: | All Airbus Helicopters Deutschland (formerly Eurocopter) BK 117 series helicopters fitted with Honeywell International (formerly AlliedSignal and Textron Lycoming) LTS101-650B1 or LTS101-750B1 model engines that have been subject to Honeywell International Service Bulletin (SB) LTS 101B-73-10-0127 Revision 2, as in force on the commencement date of this AD.                                                                                                                 |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | To prevent a power turbine overspeed and an uncontained engine failure, comply with the wiring and associated hardware installation requirements detailed in Airbus Helicopters Deutschland Service Bulletin SB-MBB-BK 117-90-103 Revision 1, as in force on the commencement date of this AD.Note 1: CASA Airworthiness Directive (AD) AD/LTS/13 Amdt 1 relates to this AD.Note 2: United States of America Federal Aviation Administration (FAA) AD 95‑26‑01 is the basis of this AD. |\n| Compliance:    | Concurrent with Requirement 2 of AD/LTS/13 Amdt 1, as in force from time to time, but before further flight after the commencement date of this AD, unless accomplished previously.                                                                                                                                                                                                                                                                                                     |\n|                | This AD commences on 20 August 2021.                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n| Background:    | This directive has been issued to require the wiring and associated hardware modifications necessary to permit the incorporation of an electronic engine overspeed controller. The requirement, in conjunction with AD/LTS/13 Amdt 1, addresses reports of uncontained power turbine overspeed events.Amendment 1 of this AD removes obsolete references and makes minor editorial changes to reflect current requirements.                                                             |\n\n![Text\nDescription automatically generated](image.001.jpeg)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n9 August 2021","sortOrder":0},{"sectionNumber":"AD/GBK 117/7 Amdt 1","sectionType":"part","heading":"AD/GBK 117/7 Amdt 1","content":"## AD/GBK 117/7 Amdt 1","sortOrder":1},{"sectionNumber":"Retrofit of Engine Overspeed Controller","sectionType":"part","heading":"Retrofit of Engine Overspeed Controller","content":"## Retrofit of Engine Overspeed Controller","sortOrder":2},{"sectionNumber":"16/2021","sectionType":"part","heading":"16/2021","content":"## 16/2021","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 1 removes obsolete references and makes minor editorial changes; the substantive retrofit requirement and applicability remain unchanged (Background)."},"complexity_factors":["Applicability: narrow, technical scope limited to MBB‑BK 117 helicopters with specified Honeywell LTS101 engine models that have been subject to a specific Honeywell service bulletin (Applicability).","Requirement: mandates a technical wiring and hardware retrofit per Airbus Service Bulletin SB‑MBB‑BK 117‑90‑103 Revision 1 (Requirement).","Compliance timing: immediate operational constraint — retrofit required before further flight and to be done concurrently with Requirement 2 of AD/LTS/13 Amdt 1 (Compliance).","Cross-references: links to another CASA AD (AD/LTS/13 Amdt 1) and cites FAA AD 95‑26‑01 as the basis, requiring coordination across documents (Requirement / Background).","Administrative change only: Amendment 1 removes obsolete references and makes editorial changes rather than altering substantive obligations (Background).","Operational burden: imposes direct costs on operators for parts, maintenance labour, downtime and record checks to confirm whether the engines were subject to the referenced Honeywell SB (Applicability / Requirement).","Low regulator discretion: as an airworthiness directive it is mandatory with a clear compliance trigger (Commencement date and Compliance)."],"plain_english_summary":"This AD requires operators of Airbus Helicopters MBB‑BK 117 series fitted with Honeywell LTS101‑650B1 or LTS101‑750B1 engines (where those engines have been subject to Honeywell SB LTS 101B‑73‑10‑0127 Rev 2) to install wiring and associated hardware so an electronic engine overspeed controller can be incorporated, following Airbus Service Bulletin SB‑MBB‑BK 117‑90‑103 Rev 1. It is intended to prevent power turbine overspeed and uncontained engine failure; compliance is mandatory before further flight and must be done concurrent with Requirement 2 of AD/LTS/13 Amdt 1."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing AD. The amendment makes only minor editorial changes and removes obsolete references. The scope remains identical to the original 2021 directive — requiring the same wiring retrofit for the same helicopter/engine combinations. No expansion of applicability or additional requirements."},"complexity_factors":["Short, single-purpose directive with one primary requirement","Only 4 defined/referenced documents (two service bulletins, one related AD, one FAA AD)","Simple conditional logic: compliance required 'before further flight' unless already done","Cross-references to one related Australian AD and one US FAA AD for context","Narrow applicability criteria involving three nested conditions (helicopter model + engine model + prior service bulletin applicability)","No subsections, parts, or schedules — single integrated requirement"],"plain_english_summary":"This AD requires operators of Airbus Helicopters Deutschland BK 117s with Honeywell LTS101‑650B1 or LTS101‑750B1 engines (already modified per the specified Honeywell bulletin) to install wiring and hardware to enable an electronic engine overspeed controller, addressing reported power‑turbine overspeed events that can cause uncontained engine failure. Work must be done before flight after 20 August 2021 and alongside the related LTS AD; this amendment makes editorial updates to the original 2021 directive."},"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-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller","history":"/api/acts/ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller/history","analysis":"/api/acts/ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller/analysis","conflicts":"/api/acts/ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller/conflicts","importantCases":"/api/acts/ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller/important-cases","documents":"/api/acts/ad-gbk-117-7-amdt-1-retrofit-of-engine-overspeed-controller/documents"}}