{"id":"F2006B07510","name":"AD/TSA-600/46 - Main Landing Gear Lower Side Brace","slug":"ad-tsa-600-46-main-landing-gear-lower-side-brace","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50005,"registerId":"commonwealth-F2006B07510-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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\nAerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/TSA-600/46 Main Landing Gear Lower Si","sectionType":"part","heading":"AD/TSA-600/46 Main Landing Gear Lower Side Brace 8/2001","content":"# AD/TSA-600/46 Main Landing Gear Lower Side Brace 8/2001\n\nApplicability: Model PA-60-600, PA-60-601, PA-60-601P, PA-60-602P, and PA-60-700P aircraft, serial numbers 1 through 1026.\n\nRequirement: Replace both main landing gear lower side brace assemblies with Aerostar part number 400084-001 lower side brace assemblies, in accordance with Instructions Part II Replacement paragraph of Aerostar Service Bulletin SB600-134A, dated 31 March 2000; and the Aerostar Maintenance Manual.\n\nNote: FAA AD 2001-08-10 Amdt 39-12187 refers.\n\nCompliance: Within 50 hours time in service after 9 August 2001, unless already accomplished.\n\nThis Airworthiness Directive becomes effective on 9 August 2001.\n\nBackground: The FAA received several reports of cracking of the main landing gear lower side brace at the upper bolt lug. Cracking was found during pre-flight inspection, and failure could lead to loss of control of the aircraft. This Directive requires replacement of existing lower side brace assemblies with parts of improved design.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 26 June 2001\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"No scope change indicated in the text. The AD's scope matches its stated purpose: require replacement of lower side brace assemblies on the listed PA-60 models/serials to address reported cracking at the upper bolt lug and prevent potential landing gear failure (Requirement; Background; Compliance)."},"complexity_factors":["Narrow, well-defined applicability (specific models and serial numbers) — limits affected population.","Single remedial action: replacement of both lower side brace assemblies with a specified part number (low technical variety). (Requirement)","Cross-document dependency: mandates adherence to Aerostar Service Bulletin SB600-134A and Aerostar Maintenance Manual — operators must obtain and follow external instructions. (Requirement)","Short compliance window (50 hours TIS after 9 August 2001) increases operational scheduling pressure for operators and maintenance providers. (Compliance)","Safety-critical failure mode (cracking at the upper bolt lug) creates high urgency but straightforward corrective step. (Background)","Administrative burden for fleet managers to track compliance across serial-numbered aircraft and record work completion."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Aerostar (Piper/Ted Smith) PA-60-600/601/601P/602P/700P (serials 1–1026) to replace both main landing gear lower side brace assemblies with Aerostar part 400084-001, following Aerostar Service Bulletin SB600-134A and the Aerostar Maintenance Manual. Compliance is mandatory within 50 hours time-in-service after 9 August 2001. The directive responds to reported cracking at the upper bolt lug that could cause landing gear failure and loss of control."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific mechanical defect in a defined aircraft type and mandates a specific remedial action. There is no evidence of scope creep; the instrument remains a targeted safety intervention consistent with the standard purpose of ADs under the Civil Aviation Regulations."},"complexity_factors":["Single, unambiguous requirement with one specific action (replacement of named parts)","Clear applicability limited to 5 specific aircraft models with defined serial number range","Only one compliance condition (50 hours time in service) with single exception (already accomplished)","No nested definitions, cross-references to other legislation, or conditional logic beyond the basic applicability test","References external technical documents (Service Bulletin, Maintenance Manual) but does not incorporate them by complex statutory mechanism — simply directs compliance with them","Total length: approximately 250 words of substantive text"],"plain_english_summary":"This safety order requires owners/operators of Aerostar PA-60-600 through PA-60-700P (S/N 1–1026) to replace both main landing gear lower side brace assemblies with Aerostar P/N 400084-001, following the manufacturer's service bulletin and maintenance manual. It’s mandatory within 50 flying hours of 9 Aug 2001 because cracks at the upper bolt lug can lead to gear failure and loss of control; aircraft may not fly past the compliance deadline without the repair."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace","history":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace/history","analysis":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace/analysis","conflicts":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace/conflicts","importantCases":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace/important-cases","documents":"/api/acts/ad-tsa-600-46-main-landing-gear-lower-side-brace/documents"}}