{"id":"F2006B07505","name":"AD/TSA-600/41 Amdt 2 - NLG Lower Drag Brace Assembly","slug":"ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49988,"registerId":"commonwealth-F2006B07505-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TSA-600/41 Amdt 2 - NLG Lower Drag Brace Assembly","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)  \nAerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes\n\nAD/TSA-600/41\n\nAmdt 2\n\n  \nNLG Lower Drag Brace Assembly 3/95\n\nApplicability: Models and serial numbers as listed in Aerostar Service Bulletin 600-128.\n\nRequirement: Replace the nose landing gear lower drag brace link assembly with an improved assembly in accordance with Aerostar SB 600-128.\n\nNote: FAA AD 94-15-13 Amdt 39-8984 refers.\n\nCompliance: Unless already accomplished, prior to 2 March 1996.\n\nBackground: The FAA received reports of corrosion in the spring and piston in the lower drag link of the nose landing gear drag brace assembly.\n\nAmendment 1 introduced an improved drag brace link assembly as an alternative to replacement of the spring and piston, which are no longer available from the manufacturer.\n\nAmendment 2 is issued in response to a new FAA AD which requires applicable aircraft already modified in accordance with the initial issue of this Directive, to have the drag brace link assembly replaced with the improved drag brace link assembly.\n\nThe FAA has received several reports of frozen moisture in the cylinder of the over- centre release mechanism, which has led to nose gear collapse on aircraft already in compliance with FAA AD 92-13-01.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: preventing nose landing gear collapse in Aerostar aircraft due to moisture/corrosion issues in the drag brace assembly. While Amendment 2 expands the mandate to cover aircraft previously modified under earlier versions, this is a refinement of the same safety objective rather than scope creep. The directive has not expanded to cover different aircraft types, different failure modes, or unrelated systems."},"complexity_factors":["Single, specific mechanical modification required (replacement of one assembly)","Only 2 defined applicability criteria (model series and serial numbers referenced externally)","Simple compliance structure: one action required by one deadline","Background narrative is explanatory rather than creating additional legal conditions","Cross-reference to FAA AD is informational only, not creating layered compliance obligations","No nested exceptions or conditional logic — straightforward 'unless already accomplished' exemption"],"plain_english_summary":"This CASA Airworthiness Directive mandates that owners/operators of Aerostar 600 and 700 series aeroplanes (serials listed in Aerostar Service Bulletin 600‑128) replace the nose landing gear lower drag brace link assembly with the improved part by 2 March 1996. Moisture can freeze in the original over‑centre release mechanism and cause nose‑gear collapse; earlier spring/piston fixes are now deemed inadequate, so the new replacement is required even on aircraft previously modified."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 2 expands the scope to require replacement with the improved drag brace link assembly even for aircraft that were previously modified under the initial issue of this Directive. (Source: 'Amendment 2 is issued... requires applicable aircraft already modified in accordance with the initial issue of this Directive, to have the drag brace link assembly replaced with the improved drag brace link assembly.')"},"complexity_factors":["Narrow applicability tied to specific models and serial numbers referenced in Aerostar SB 600-128 — requires operators to check aircraft identity against the Service Bulletin.","Technical, hands-on maintenance: mandatory physical replacement of the nose landing gear lower drag brace link assembly per manufacturer instructions.","Cross-references to FAA airworthiness directives and prior amendments create a history to track for compliance status.","Fixed compliance deadline (prior to 2 March 1996) creates scheduling and operational constraints for operators.","Original spare parts (spring and piston) are no longer available, forcing a retrofit to the improved assembly.","Mandate language ('Requirement: Replace...') leaves little regulatory discretion; non-compliance carries regulatory risk for operators."],"plain_english_summary":"This directive requires owners/operators of Aerostar (Piper/Ted Smith) 600 and 700 series aircraft listed in Aerostar Service Bulletin 600-128 to replace the nose landing gear lower drag brace link assembly with an improved assembly, in accordance with that Service Bulletin. Compliance is required before 2 March 1996 unless already done.\n\nCASA issued the requirement after FAA reports of corrosion, unavailable spring/piston parts, and frozen moisture causing nose-gear collapses. The replacement cost and maintenance scheduling fall to aircraft owners/operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly","history":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly/history","analysis":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly/analysis","conflicts":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly/conflicts","importantCases":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly/important-cases","documents":"/api/acts/ad-tsa-600-41-amdt-2-nlg-lower-drag-brace-assembly/documents"}}