{"id":"F2006B04776","name":"AD/BN-2/64 Amdt 1 - Propeller Anti-Ice System","slug":"ad-bn-2-64-amdt-1-propeller-anti-ice-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44552,"registerId":"commonwealth-F2006B04776-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/64 Amdt 1 - Propeller Anti-Ice System","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)  \nPilatus Britten-Norman BN-2 Series Aeroplanes\n\nAD/BN-2/64\n\nAmdt 1\n\n  \nPropeller Anti-Ice System 4/99 DM\n\nApplicability: BN2T series Islander aeroplanes without modification NB-M-1662 incorporated.\n\nRequirement: 1. Inspect the electrical cables, cable looms and other components of the propeller anti-ice system in accordance with Pilatus Britten-Norman Aircraft Manufacturers Service Bulletin (SB) BN2/SB.250 dated 6 July 1998.\n\n    2. If any of the cables or components are found to be unserviceable during the Requirement 1 inspection, either repair or replace the effected cables or components.\n\n    3. Modify the engine intake and propeller anti-ice electrical system in accordance with Britten-Norman SB BN2/SB.250 Issue 2 dated 1 December 1998.\n\nNote: Both SBs have been classified as Mandatory by the CAA(UK) and CAA(UK) AD 005-07-98 also refers.\n\nCompliance: 1. Remains unchanged as ‘Before further flight after 11 November 1998’.\n\n    2. Remains unchanged as ‘Before further flight’.\n\n    3. At the next 100 hour inspection after the effective date of this amendment or by 17 June 1999, which ever occurs first.\n\nThis Amendment becomes effective on 17 March 1999.\n\nBackground: Heat damage has been reported to the left propeller anti-ice electrical cables and cable loom attachments of a BN2T aeroplane. The damage was caused as a result of a electrical short circuit when insulation of one of the harness cables was worn by chafing in the spinner assembly. The applicable fuse did not function and the cables became too hot with the subsequent high current flow.\n\nThe original issue of the directive required inspection and, if necessary, repair of anti- ice electrical cables, looms and components. This amendment requires modification of the engine intake and propeller anti-ice electrical system to provide better circuit protection.\n\nThe original issue of this Airworthiness Directive became effective on 11 November 1998.","sortOrder":0}],"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. The original AD required inspection and repair of anti‑ice electrical cables and components. This amendment adds a mandatory modification of the engine intake and propeller anti‑ice electrical system to provide improved circuit protection (Requirement 3), changing the remedy from inspection/repair only to inspection/repair plus a system modification; compliance timing for the new modification is set to the next 100‑hour inspection or by 17 June 1999 (Compliance)."},"complexity_factors":["Narrow applicability — BN2T series Islander aeroplanes without modification NB‑M‑1662 (Applicability).","Three distinct mandatory actions: inspect, repair/replace, and modify (Requirements 1–3).","Multiple and staged compliance deadlines: before further flight; before further flight for repairs; next 100‑hour inspection or by 17 June 1999 for modification (Compliance).","Dependence on external manufacturer documents: Pilatus Britten‑Norman SB BN2/SB.250 (dated 6 Jul 1998) and BN2/SB.250 Issue 2 (1 Dec 1998) (Requirements 1 & 3).","Technical and safety‑critical subject matter — electrical wiring, cable looms and circuit protection in anti‑ice system (Background; Requirements).","Cross‑jurisdictional reference: CAA(UK) classified the SBs as Mandatory and CAA(UK) AD 005‑07‑98 is referred to (Note).","Operational impact timing: immediate actions (before next flight) plus a later mandatory modification window, creating short‑term and medium‑term compliance burdens (Compliance)."],"plain_english_summary":"This Airworthiness Directive requires operators of Pilatus Britten‑Norman BN2T Islanders (unless modification NB‑M‑1662 is fitted) to inspect and, if needed, repair propeller anti‑ice wiring and to modify the engine intake/propeller anti‑ice electrical system to add circuit protection. It responds to heat/short‑circuit damage found in service.\n\nThe Civil Aviation Safety Authority mandates inspection (Req 1), repair/replace (Req 2) and modification (Req 3) with staged compliance: inspections before next flight, modification by the next 100‑hour check or 17 June 1999. Operators bear costs and must follow Britten‑Norman SB BN2/SB.250."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original safety purpose. It adds a mandatory modification requirement to the original inspection-and-repair directive, but this is a logical extension addressing the same electrical fault issue rather than scope creep. The amendment does not expand to other aircraft types, systems, or operational areas."},"complexity_factors":["Single, specific aircraft type and model series (BN-2T Islander)","Only 3 operational requirements with clear sequential logic","Minimal defined terms (only 'Applicability' and 'Compliance' as standard headers)","No cross-references to other legislation or regulations beyond noting related UK authority directives","Straightforward conditional logic: if unserviceable → repair/replace","Clear deadlines with specific dates and alternative compliance paths"],"plain_english_summary":"This safety order requires owners/operators of Pilatus Britten‑Norman BN‑2T Islander aircraft (without factory mod NB‑M‑1662) to urgently inspect and, if needed, repair propeller anti‑ice electrical wiring and components to eliminate worn insulation and short‑circuit risks. \n\nIt also mandates a system modification to add improved circuit protection at the next major maintenance interval to prevent in‑flight electrical fires or propeller failures that could cause loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system","history":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system/history","analysis":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system/analysis","conflicts":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system/conflicts","importantCases":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system/important-cases","documents":"/api/acts/ad-bn-2-64-amdt-1-propeller-anti-ice-system/documents"}}