{"id":"F2006B09431","name":"AD/ELECT/57 Amdt 1 - Landing Gear - Dunlop Fan and Transducer Installation","slug":"ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53838,"registerId":"commonwealth-F2006B09431-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ELECT/57 Amdt 1 - Landing Gear - Dunlop Fan and Transducer Installation","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n![](image.002.png)  \nElectrical Equipment\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.003.png)For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ELECT/57 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\nApplicability: Dunlop Fan and Transducer Installation Part Numbers AHA1578, AHA1684 AND AHA1685.\n\n![](image.004.png)Note 1: Aircraft known to be fitted with these Fan and Transducer installations include but are not limited to BAe 146 aircraft.\n\nRequirement: Replace the fan and transducer installation in accordance with Dunlop Limited Aviation Division Service Bulletin (SB) 32-1039.\n\n![](image.005.png)Note 2: Incorporation of Modification C2640 in accordance with Dunlop Limited Aviation Division SB AHA 1684/AHA1685-32-1047 dated 19 September 1990 in BAe 146 aircraft is considered terminating action for this Directive for those aircraft.\n\nNote 3: Compliance with this Service Bulletin has been classified mandatory by the UK CAA.\n\nCompliance: Remains unchanged as - “Initially, prior to 28 February 1991, and thereafter at intervals not exceeding 1500 landings. Operators with positive records of both transducer drive shaft and splined drive replacement may allow these components to continue in service until they have completed 1500 landings from the last replacement.”\n\nThis Amendment becomes effective on 1 November 2001.\n\nBackground: Wear in the transducer drive splines can cause the transducer to produce false signals. These signals may be interpreted as skids by the anti skid control box, and may result in reduced braking performance or loss of braking.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.006.png)This amendment introduces terminating action for BAe 146 aircraft and minor formatting amendments. The original issue of this Directive became effective on 29 November 1990.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.007.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 13 September 2001\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 10 October 2001.","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":3,"scope_assessment":{"changed":true,"description":"Yes. The amendment adds a terminating action for BAe 146 aircraft where Modification C2640 has been incorporated per Dunlop SB AHA1684/AHA1685‑32‑1047 and records that this AD originally took effect in 1990; otherwise the replacement requirement and 1,500‑landing interval remain unchanged."},"complexity_factors":["Technical maintenance requirement referencing manufacturer Service Bulletins rather than standalone instructions (SB 32‑1039 and SB AHA1684/AHA1685‑32‑1047).","Multiple affected part numbers (AHA1578, AHA1684, AHA1685) and cross‑reference to aircraft types (notably BAe 146).","Scheduled recurring compliance interval (1500 landings) requiring operator record‑keeping and tracking.","Terminating action available for a specific aircraft type via incorporation of Modification C2640, creating conditional scope.","Mandatory classification by UK CAA referenced, creating an international regulatory cross‑link.","Effective dates and historical amendment history (original AD and this Amendment effective 1 Nov 2001) that operators must reconcile with maintenance records."],"plain_english_summary":"This Airworthiness Directive requires operators to replace specified Dunlop landing-gear fan and transducer assemblies (P/Ns AHA1578, AHA1684, AHA1685) in accordance with Dunlop Service Bulletin 32‑1039 and to meet the existing 1,500‑landing inspection/replacement interval. It affects aircraft fitted with those parts (including BAe 146) because wear in the transducer drive splines can create false skid signals and reduce braking. The amendment adds a terminating modification (C2640) for BAe 146 when embodied per Dunlop SB AHA1684/AHA1685‑32‑1047."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of addressing unsafe wear in Dunlop fan and transducer installations. The amendment does not expand applicability to new aircraft types or part numbers; it merely adds a terminating action for BAe 146 aircraft (which were already covered) and makes minor formatting changes. The core safety mandate remains unchanged."},"complexity_factors":["Short, single-purpose directive focused on one specific mechanical issue","Only 3 part numbers in applicability section","Single requirement referencing an external technical document (Service Bulletin 32-1039)","Compliance section contains conditional logic (1500-landing intervals vs. exception for operators with positive replacement records)","Contains terminating action provision (Modification C2640) that references a second external document","Minimal defined terms (relies on industry-standard aviation terminology)","No nested legislative cross-references beyond basic CAR 1998 subregulation 39.1(1) citation"],"plain_english_summary":"This CASA airworthiness directive targets Dunlop fan-and-transducer units fitted to some BAe 146 landing gear. Worn transducer drive splines can produce false anti‑skid signals that may reduce braking effectiveness or cause brake failure, so operators must replace affected units per Dunlop Service Bulletin on a 1,500‑landing cycle (initial replacement due before 28 Feb 1991, with credit for recent shaft/spline replacements).\n\nAmendment 1 adds terminating action: aircraft modified per Dunlop SB incorporating Modification C2640 no longer require repeat replacements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation","history":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation/history","analysis":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation/analysis","conflicts":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation/conflicts","importantCases":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation/important-cases","documents":"/api/acts/ad-elect-57-amdt-1-landing-gear-dunlop-fan-and-transducer-installation/documents"}}