{"id":"F2006B10323","name":"AD/GROB 115/4 - Firewall Bonding Lead","slug":"ad-grob-115-4-firewall-bonding-lead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56077,"registerId":"commonwealth-F2006B10323-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GROB 115/4 - Firewall Bonding Lead","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)  Grob G115 Series Aeroplanes\n\n \n\nAD/GROB 115/4 Firewall Bonding Lead 11/91\n\nApplicability: All G115A series aircraft S/No 8091 through 8109 inclusive, except S/Nos 8097, 8100 and 8102.\n\n \n\nRequirement: Action in accordance with the technical requirements of GROB G115 Service Bulletin TM 1078-18.\n\n \n\nCompliance: Within 25 hours Time in Service after 14 November 1991.\n\n \n\nBackground: Grob have advised that during engine start, there is a possibility that a high resistance may occur at the bonding lead assembly mounted at the firewall.\n\n \n\nThis may cause a reverse current to occur which may damage wiring and other aircraft components. To prevent this, the existing bonding bolt plate must be replaced with a modified bonding bolt plate (P/No 115-9006).\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1991 for a specific airworthiness issue. It has not expanded beyond its original purpose of addressing the firewall bonding lead defect in the specified aircraft."},"complexity_factors":["Single, specific technical requirement with clear reference to external service bulletin","Narrow applicability limited to 16 specific aircraft serial numbers with 3 explicit exclusions","Simple compliance deadline (25 hours Time in Service after fixed date)","No defined terms section, no cross-references to other legislation, no conditional logic or exceptions beyond the serial number exclusions","Total length is 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) that requires specific aircraft owners to fix a dangerous electrical fault.\n\n**What it does:**\nOrders owners of certain **Grob G115A training aircraft** (serial numbers 8091–8109, excluding three specific planes) to replace a faulty electrical component called a \"bonding bolt plate\" on the firewall (the wall between the engine and the cockpit).\n\n**Why it matters:**\nThe original part can develop high electrical resistance during engine starts. This can cause **reverse electrical current** that damages wiring and other aircraft systems — a serious safety risk in flight.\n\n**Who must act:**\n- Owners/operators of affected Grob G115A aircraft\n- Must complete the fix within **25 flight hours** after 14 November 1991\n- Must follow the technical instructions in **Grob Service Bulletin TM 1078-18**\n\n**The fix:**\nReplace the existing bonding bolt plate with a modified part (part number 115-9006)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive confines its effect to specified G115A serial numbers and prescribes a single, one-off hardware replacement per the service bulletin. The text contains no indication that it expands or narrows scope beyond that stated applicability and requirement (Applicability; Requirement)."},"complexity_factors":["Limited applicability — applies only to a small, specific set of serial numbers (Applicability).","Prescriptive technical action — mandates replacement per manufacturer's Service Bulletin TM 1078-18, so compliance requires following that external document (Requirement).","Time-critical compliance — work must be done within 25 hours TIS after 14 November 1991, creating a short window for scheduling and parts procurement (Compliance).","Part-specific change — requires a particular replacement part (P/No 115-9006), meaning operators must source that item and bear procurement/installation costs (Background; Requirement).","Safety rationale stated — the AD is prompted by a risk that high resistance at the firewall bonding lead may cause reverse current and ensuing wiring/component damage (Background).","Limited regulatory discretion — the AD sets a clear mandatory action and deadline; no alternate methods or waivers are provided in the text, so enforcement rests on meeting the directive as written (Requirement; Compliance)."],"plain_english_summary":"This airworthiness directive requires owners/operators of certain Grob G115A aircraft (S/N 8091–8109, except 8097, 8100, 8102) to replace the firewall bonding bolt plate with a modified part (P/No 115-9006) in accordance with GROB Service Bulletin TM 1078-18. The replacement must be completed within 25 hours time-in-service after 14 November 1991 to prevent possible reverse current that could damage wiring and other components."}},"importantCases":[],"_links":{"self":"/api/acts/ad-grob-115-4-firewall-bonding-lead","history":"/api/acts/ad-grob-115-4-firewall-bonding-lead/history","analysis":"/api/acts/ad-grob-115-4-firewall-bonding-lead/analysis","conflicts":"/api/acts/ad-grob-115-4-firewall-bonding-lead/conflicts","importantCases":"/api/acts/ad-grob-115-4-firewall-bonding-lead/important-cases","documents":"/api/acts/ad-grob-115-4-firewall-bonding-lead/documents"}}