{"id":"F2006B09434","name":"AD/ELECT/6 - Magneto - BTH - Contact Breakers Assembly - Modification","slug":"ad-elect-6-magneto-bth-contact-breakers-assembly-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53846,"registerId":"commonwealth-F2006B09434-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/ELECT/6 - Magneto - BTH - Contact Breakers Assembly - Modification","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)  \nElectrical Equipment\n\nAD/ELECT/6 Magneto \\- BTH \\- Contact Breakers NK\n\nAssembly \\- Modification\n\nApplicability: All BTH type AG4, SG4 and MC1 magnetos fitted with contact breaker assemblies incorporating an automatic earthing device which short circuits the magneto primary winding when the contact breaker cover is removed.\n\nRequirement: 1. Remove the automatically earthing type contact breaker assembly and:\n\n    (a) Replace with a contact breaker assembly which does not have provision for automatically earthing the magneto primary winding; or\n\n    (b) Modify the existing contact breaker assembly by removing the automatic earthing features.\n\n    2. Reassemble the contact breaker assembly to the magneto using a retaining screw having the standard type of head which provides direct contact for the carbon button in the contact breaker cover.\n\n    3. Remove the coiled wire spring from the contact breaker cover. or ANO 107.2.16.2.5.\n\nCompliance: Before installation in an aircraft.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2108},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow technical scope, targeting only specific BTH magneto models for a defined safety modification. There is no indication of scope creep beyond the original equipment safety issue."},"complexity_factors":["Technical aviation terminology requiring mechanical knowledge (magnetos, contact breakers, earthing devices)","Specific model number references (AG4, SG4, MC1) that require technical cross-checking","Single alternative compliance pathway referenced via shorthand (ANO 107.2.16.2.5)"],"plain_english_summary":"A safety directive requires mechanics to disable a hazardous \"automatic earthing\" feature in certain BTH magnetos (AG4, SG4, MC1) before installation because it can short electrical systems when the maintenance cover is removed, risking fire or equipment damage. Affected aircraft mechanics and owners must replace or modify the contact‑breaker assembly to remove the earthing device, fit the correct standard‑head retaining screw, and remove the coiled cover spring."}},"importantCases":[],"_links":{"self":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification","history":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification/history","analysis":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification/analysis","conflicts":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification/conflicts","importantCases":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification/important-cases","documents":"/api/acts/ad-elect-6-magneto-bth-contact-breakers-assembly-modification/documents"}}