{"id":"F2006B04728","name":"AD/BN-2/17 Amdt 1 - Elevator Trim Jack - Inspection and Modification","slug":"ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44492,"registerId":"commonwealth-F2006B04728-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/17 Amdt 1 - Elevator Trim Jack - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Pilatus Britten-Norman BN-2 Series Aeroplanes\n\n \n\nAD/BN-2/17\n\nAmdt 1\n\n\nElevator Trim Jack - Inspection and Modification NK\n\n \n\nApplicability: All models not incorporating Modification NB/M/468.\n\n \n\nRequirement: 1. Using a dye penetrant method inspect the elevator trim jack eye end for cracking paying particular attention to the corners of the cutout which allows for removal of the bearing from the cage.\n\n \n\n2. Incorporate new eye end to modification NB/M/468.\n\n \n\nCompliance: Within 100 hours time in service after 27 January 1971 and there- after at intervals not exceeding 20 hours time in service. Modify before 28 February 1971.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument's scope is stated plainly: it applies to all BN-2 series aeroplanes not already incorporating Modification NB/M/468 and requires inspection and incorporation of that modification. The text does not expand or narrow that stated scope beyond those terms (Applicability; Requirement; Compliance)."},"complexity_factors":["Clear applicability limited to BN-2 series not incorporating Modification NB/M/468 (Applicability).","Single technical inspection method specified (dye penetrant) and a single mod to be incorporated (NB/M/468) (Requirement).","Specific, short compliance timeline with one recurring interval and one hard modification deadline (Compliance).","Technical nature of inspection (attention to cutout corners) raises operational/skill requirements but does not add legal complexity (Requirement).","No alternative compliance paths, exemptions, or layered conditions in the text, reducing legal complexity (Requirement; Compliance)."],"plain_english_summary":"Owners/operators of Pilatus Britten‑Norman BN‑2 aeroplanes without Modification NB/M/468 must perform dye‑penetrant inspections of the elevator trim jack eye end (focus on bearing cutout corners) within 100 hours TIS and every 20 hours thereafter, and fit modification NB/M/468 by the deadline. It targets cracking risk; maintenance providers do the work and operators pay inspection and modification costs, affecting scheduling and availability."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a historical airworthiness directive from 1971 with a narrow, specific scope addressing a known safety defect in a particular aircraft component. It has not expanded beyond its original purpose."},"complexity_factors":["Single, specific aircraft type (Pilatus Britten-Norman BN-2 series)","Only two technical requirements (inspect and modify)","No defined terms section","No cross-references to other legislation","Simple conditional logic (applies only to aircraft without Modification NB/M/468)","Clear, fixed compliance dates and intervals","Total length: approximately 150 words of substantive content"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nThis directive requires owners and operators of **Pilatus Britten-Norman BN-2 series aeroplanes** (small twin-engine aircraft commonly used for regional transport and island hopping) to:\n\n- **Inspect** the elevator trim jack eye end for cracks using a dye penetrant method (a special fluid that seeps into tiny cracks to make them visible), with particular attention to the corners of a cutout area\n- **Modify** the aircraft by installing a new eye end part according to modification specification NB/M/468\n\n**Who it affects:**\nAll BN-2 aircraft that haven't already been modified with NB/M/468.\n\n**Why it matters:**\nThe elevator trim jack is a critical control component that helps pilots adjust the aircraft's pitch (nose up/down). Cracks in this part could lead to control failure — potentially catastrophic. This directive prevents accidents by catching fatigue damage early and mandating a stronger replacement part.\n\n**When to comply:**\n- Initial inspection: within 100 flight hours after 27 January 1971\n- Repeat inspections: every 20 flight hours thereafter\n- Modification deadline: before 28 February 1971"}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification","history":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification/history","analysis":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification/analysis","conflicts":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification/important-cases","documents":"/api/acts/ad-bn-2-17-amdt-1-elevator-trim-jack-inspection-and-modification/documents"}}