{"id":"F2006B04781","name":"AD/BN-2/69 Amdt 1 - Throttle Friction Adjuster","slug":"ad-bn-2-69-amdt-1-throttle-friction-adjuster","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44558,"registerId":"commonwealth-F2006B04781-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/69 Amdt 1 - Throttle Friction Adjuster","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BN-2/69 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nPilatus Britten-Norman BN-2 Series Aeroplanes\n\nAD/BN-2/69\n\nAmdt 1\n\n  \nThrottle Friction Adjuster 4/2003\n\nApplicability: Model BN2, BN2A, BN2B, BN2T and BN2T-4 series Islander aircraft. Requirement: Action in accordance with Britten-Norman Service Bulletin (SB) BN2/SB.272 Issue\n\n2.\n\nNote: The UK CAA has deemed Britten-Norman SB BN2/SB.272 Issue 2 mandatory.\n\nCompliance: Unless previously inspected in accordance with Britten-Norman SB BN2/SB.272 Issue 2 or earlier revision; within 10 flight hours from the effective date of this Directive. Thereafter at intervals not to exceed 200 flight hours.\n\nThis Amendment becomes effective on 17 April 2003.\n\nBackground: This Amendment details changes in requirements to only replace hardware as required, and an increase in the inspection interval.\n\nThis Directive was originally raised after a report of a throttle friction adjuster being loosened too far. This caused the split pin and washer on the end of the shaft to be broken.\n\nThe original issue of this Airworthiness Directive became effective on 9 August 2000.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 14 February 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 March 2003.\n\n  \nPage 1 of 1","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This Amendment does not expand the AD beyond its original safety purpose. It narrows operational requirements compared with the original AD by making replacement of hardware conditional on inspection findings and by extending the recurrent inspection interval to 200 flight hours. Those are changes to the stringency and frequency of obligations, not an extension of the class of aircraft or the safety concern addressed."},"complexity_factors":["Short document (one page) with limited provisions","Single technical cross‑reference to Britten‑Norman Service Bulletin BN2/SB.272 Issue 2","Simple conditional logic: initial inspection within 10 flight hours unless already done; thereafter every 200 flight hours","Change from previous AD limited to replacement‑only‑if‑required and increased intervals (no multilayered exceptions)","No large set of defined terms or multiple Parts; only one applicability clause (BN2 family models)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires regular inspection of the throttle friction adjuster on Pilatus Britten‑Norman Islander aeroplanes (models BN2, BN2A, BN2B, BN2T and BN2T‑4). (Applicability; Requirement)\n- Operators must carry out the inspection in accordance with Britten‑Norman Service Bulletin BN2/SB.272 Issue 2 (or the earlier revision). The UK CAA has declared that Service Bulletin mandatory. (Requirement; note)\n- If the aircraft has not already been inspected to that Service Bulletin, the first inspection must be done within 10 flight hours of the Directive becoming effective. After that, inspections must be repeated at intervals not to exceed 200 flight hours. (Compliance)\n- Replacement of hardware is required only when the inspection shows it to be necessary (this Amendment changes the previous requirement to allow replacement only as required). (Background)\n\n**Who is affected**\n\n- Owners and operators of Pilatus Britten‑Norman BN‑2 series Islander aircraft. Maintenance organisations and engineers who perform inspections and any required repairs or part replacements are also affected. (Applicability; Requirement)\n\n**Why it matters**\n\n- The Directive addresses a known unsafe condition: a report that a throttle friction adjuster had been wound out too far, which led to breakage of the split pin and washer on the shaft end. The inspections and any necessary replacement are intended to detect and correct that condition before it leads to failure. (Background)\n\n**How the law works in practice**\n\n- The regulator (the CASA delegate) mandates compliance by referring to the manufacturer’s Service Bulletin; operators must follow that technical document’s inspection and repair instructions. (Requirement)\n- The initial inspection timing is short (within 10 flight hours if not already done), then recurring at up to 200 flight‑hour intervals. (Compliance)\n- Only if the inspection reveals wear, damage or improper adjustment is hardware removed and replaced — the Amendment changes the prior rule so replacement is not automatic. (Background)\n\n**Costs, incentives and trade‑offs**\n\n- Who pays: aircraft owners/operators pay for the inspections and for any replacement parts and labour. (Requirement; Compliance)\n- Incentives: making replacement conditional on inspection creates an incentive to rely on inspection findings rather than replace parts pre‑emptively, reducing immediate maintenance costs but increasing reliance on inspection quality. (Background; Requirement)\n- Trade‑off: the longer recurrent interval (200 flight hours) lowers maintenance frequency and cost compared with more frequent inspections, but extends the period during which a developing fault might go undetected if inspections are not thorough. (Background; Compliance)\n- Implementation risk and compliance burden: the requirement depends on access to and correct application of the specified Service Bulletin. Operators must track compliance times and keep records. The practical burden is modest — routine inspection intervals and targeted replacement — but depends on maintenance capacity and record systems. (Requirement; Compliance)\n\n**Decision and enforcement mechanics**\n\n- The CASA delegate issues the Directive under the Civil Aviation Regulations and enforces compliance by requiring the specified inspection and repair actions tied to the manufacturer’s Service Bulletin. The UK CAA’s characterization of the Service Bulletin as mandatory reinforces the technical standard referenced. (Opening paragraph; Requirement; note)\n\n**Net effect compared with the original AD**\n\n- The Amendment narrows the required action in two ways: it restricts replacement to situations where inspection indicates it is necessary, and it increases the permitted interval between inspections. That reduces recurring maintenance frequency and immediate replacement costs for operators, while keeping an inspection requirement to manage the unsafe condition. (Background; Compliance)\n\n"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose — ensuring safe operation of throttle friction adjusters on specific Islander aircraft. The changes (inspection-only replacement, extended intervals) are refinements to implementation, not scope expansion."},"complexity_factors":["Single, clearly defined applicability (5 specific aircraft models)","One primary requirement referencing an external technical document (service bulletin)","Simple compliance structure: initial inspection + recurring interval","Single exception clause for previously completed inspections","No nested definitions, cross-references to other legislation, or conditional logic beyond the basic applicability and compliance timing","Total length: approximately 1 page"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Pilatus Britten‑Norman Islander aircraft (BN2 series) to inspect the throttle friction adjuster per Service Bulletin BN2/SB.272 and replace parts only if faults are found. Inspections are due within 10 flight hours of 17 April 2003 and then every 200 flight hours; previously compliant inspections remain acceptable. The amended AD relaxes mandatory hardware replacement and extends inspection intervals to reduce the risk of unexpected throttle movement or loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster","history":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster/history","analysis":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster/analysis","conflicts":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster/conflicts","importantCases":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster/important-cases","documents":"/api/acts/ad-bn-2-69-amdt-1-throttle-friction-adjuster/documents"}}