{"id":"F2008L02657","name":"AD/GBK 117/20 - Cyclic Stick","slug":"ad-gbk-117-20-cyclic-stick","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74694,"registerId":"commonwealth-F2008L02657-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter BK 117 Series Helicopters","sectionType":"division","heading":"Eurocopter BK 117 Series Helicopters","content":"### Eurocopter BK 117 Series Helicopters\n\n| AD/GBK 117/20 | Cyclic Stick | 8/2008 |\n| ------------- | ------------ | ------ |\n\n| Applicability: | Eurocopter Deutschland (ECD) GmbH MBB-BK 117 C-2 helicopters, serial number (S/N) 9004 through 9230 inclusive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. Modify the cyclic stick locking/centering device by removing the slide and spring from the cyclic stick cantilever in accordance with ECD Alert Service Bulletin (ASB) BK 117C-2-67A-008 dated 14 April 2008, or later NAA approved revision.2. Amend the Rotorcraft Flight Manual (FLM) by inserting the following note:NOTE: Before starting the engines, the cyclic stick must be moved to its neutral position. By folding up the cantilever to the pin, it is possible to move the cyclic stick into its neutral position and to centre it. A locking of the cyclic stick is no longer possible.This may be accomplished by inserting a copy of this AD into the FLM, or by FLM page(s) supplied by ECD.Note: EASA AD 2008-0113 dated 10 June 2008 refers. |\n| Compliance:    | Within 30 days after the effective date of this AD, unless previously accomplished.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n|                | This Airworthiness Directive becomes effective on 31 July 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n| Background:    | There have been several cases reported where take-off was executed with a locked cyclic stick. A locked cyclic stick may lead to loss of control of the helicopter. In order to prevent any further occurrences of inadvertent take-off with a locked cyclic stick, Eurocopter Deutschland has developed a modification of the cyclic stick cantilever. After modification, locking of the cyclic stick is no longer possible. The cyclic stick can only be centered in its neutral position.                                                                                                                                                                                                                                                                      |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n20 June 2008","sortOrder":0},{"sectionNumber":"AD/GBK 117/20","sectionType":"part","heading":"AD/GBK 117/20","content":"## AD/GBK 117/20","sortOrder":1},{"sectionNumber":"Cyclic Stick","sectionType":"part","heading":"Cyclic Stick","content":"## Cyclic Stick","sortOrder":2},{"sectionNumber":"8/2008","sectionType":"part","heading":"8/2008","content":"## 8/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope matches its stated purpose: it targets a defined set of serial numbers and mandates a physical modification plus a flight‑manual note to prevent cyclic stick locking. It does not introduce requirements beyond addressing the reported locked‑cyclic incidents or reference materials."},"complexity_factors":["Narrow applicability: specific serial numbers only (Applicability)","Single, well‑defined hardware modification referenced to an Alert Service Bulletin (Requirement)","Short mandatory compliance window (30 days) increases logistical pressure (Compliance)","Requires administrative update to the Rotorcraft Flight Manual (Requirement)","Relies on manufacturer ASB and possible later NAA‑approved revisions (Requirement)","Safety‑critical consequence if not implemented (Background) requiring qualified maintenance and potential aircraft downtime"],"plain_english_summary":"Requires owners/operators of Eurocopter Deutschland MBB‑BK 117 C‑2 helicopters (S/N 9004–9230) to modify the cyclic stick centering device by removing the slide and spring per the manufacturer Alert Service Bulletin, and to insert a flight‑manual note instructing pilots to place the cyclic in neutral before engine start (Requirement; Applicability; Compliance). The owner/operator must pay for and arrange the modification and FLM change; CASA issued the directive. Mechanically the change prevents locking of the cyclic stick to reduce the risk of take‑off with a locked cyclic (Background)."},"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 safety defect in a specific aircraft type. The scope remains precisely limited to the identified safety risk (locked cyclic stick takeoffs) and the specified helicopter fleet. No scope creep is evident."},"complexity_factors":["Single, clearly defined applicability (specific helicopter model and serial number range)","Two straightforward requirements: one mechanical modification, one documentation update","No defined terms section or complex interpretation provisions","No nested exceptions or conditional logic — simple 30-day compliance deadline","Clear reference to external technical standard (Eurocopter service bulletin) for implementation details","Short document (approximately 300 words of substantive content)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive orders owners/operators of certain Eurocopter BK 117 C‑2 helicopters (S/N 9004–9230) to remove the cyclic stick locking slide and spring per the manufacturer bulletin and update the flight manual. The change prevents pilots from accidentally taking off with the cyclic locked, closing a known safety gap that has led to loss‑of‑control incidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gbk-117-20-cyclic-stick","history":"/api/acts/ad-gbk-117-20-cyclic-stick/history","analysis":"/api/acts/ad-gbk-117-20-cyclic-stick/analysis","conflicts":"/api/acts/ad-gbk-117-20-cyclic-stick/conflicts","importantCases":"/api/acts/ad-gbk-117-20-cyclic-stick/important-cases","documents":"/api/acts/ad-gbk-117-20-cyclic-stick/documents"}}