{"id":"F2006B07155","name":"AD/SV4/1 Amdt 1 - Lower Mainplane Centre Section Tie Rods","slug":"ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49019,"registerId":"commonwealth-F2006B07155-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SV4/1 Amdt 1 - Lower Mainplane Centre Section Tie Rods","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)  \nStampe SV4 Series Aeroplanes\n\nAD/SV4/1\n\nAmdt 1\n\n  \nLower Mainplane Centre Section Tie Rods 7/88 TX\n\nApplicability: All models.\n\nRequirement: 1. Inspect the lower mainplane centre section tie rods to identify the type fitted.\n\nInspect the tie rod threads for condition, wear and damage.\n\n    2. Retire the tie rods from service.\n\nCompliance: For Requirement 1: Tie rods which have exceeded 100 hours time in service must be inspected before further flight after 25 April 1988.\n\nFor Requirement 2:\n\n    (a) Tie-rods positively identified as being to the standard required by Aerospatiale Service Bulletin Stampe No 1: Part No SV4A-S.1500.05 with rolled 10 mm x 1.5 mm threads and equipped with nuts Part No SV4A- S.1500.06, and whose threads are in good undamaged condition over the whole of their lengths: prior to exceeding 500 hours component time in service.\n\n    (b) Tie-rods positively identified as being in compliance with:-\n\n    (i) Rollason Aircraft and Engines Ltd Modification WAR 210 issue 1 (3/8\" BSF rolled threads)\n\n    (ii) Rollason Aircraft and Engines Ltd Modification WAR 210 issue 2 (10 mm x 1.5 mm cut threads)\n\nand whose threads are in good undamaged condition over the whole of their lengths: prior to exceeding 100 hours component time in service.\n\n    (c) Tie-rods that cannot be identified positively as (a) or (b) above, or whose threads show signs of wear or damage, or whose lives cannot be determined, must be replaced before further flight.\n\nNote: Tie-rods must be installed and tightened in accordance with the instructions in Aerospatiale Service Bulletin Stampe No 1. If washers are used under the nuts, spring washers must not be used.\n\nBackground: A fatal accident which occurred in the UK was caused by fatigue failure of the tie rods. The follow-up investigations have shown that the life of the Rollason tie rods must be reduced to 100 hours (UK CAA Emergency AD 011-03-88 refers). The requirement for repetitive magnetic particle inspection has been deleted. For all tie rods, the condition of the threads and the quality of the installation are critical to good fatigue performance.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment narrows maintenance scope by imposing shorter component lives for Rollason tie rods (reduced to 100 hours), establishing explicit inspection and retirement rules by tie‑rod type and condition, deleting the prior repetitive magnetic‑particle inspection requirement, and adding installation guidance (no spring washers). These changes alter maintenance timing, replacement frequency, and record/identification duties compared with the prior requirements."},"complexity_factors":["Multiple recognised tie‑rod standards/part numbers require positive identification before applying different maintenance limits (Requirement 1, Requirement 2).","Different retirement/service‑time limits (500 hours for Aerospatiale‑standard rods; 100 hours for Rollason modifications) add branching compliance rules (Requirement 2(a)/(b)).","Unknown or damaged rods must be removed before further flight, creating an immediate replacement obligation where identification or condition is unclear (Requirement 2(c)).","Immediate inspection timing: rods exceeding 100 hours required inspection before further flight after the specified date, affecting operations and scheduling (Compliance).","Installation detail — nuts/washers and prohibition on spring washers — creates a discrete assembly compliance point tied to fatigue performance (Note).","Deletion of repetitive magnetic particle inspection reduces one procedural step but increases reliance on visual/identification checks (Background).","Dependence on external documents (Aerospatiale Service Bulletin; Rollason modification WAR 210) creates documentary and record‑keeping obligations for correct compliance."],"plain_english_summary":"This Airworthiness Directive requires operators of Stampe SV4 aeroplanes to inspect and identify lower mainplane centre‑section tie rods, check thread condition, and retire or replace them depending on type and condition. It responds to a UK fatal accident attributed to tie‑rod fatigue: the AD shortens allowable life for some tie rods, removes a repetitive magnetic‑particle inspection requirement, and mandates correct installation practice (for example, no spring washers)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific safety-critical component (tie rods) on a specific aircraft type (Stampe SV4). The amendment (Amdt 1) appears to simplify the original directive by removing the requirement for repetitive magnetic particle inspection, rather than expanding scope. The document remains tightly focused on preventing fatigue failure of this single component."},"complexity_factors":["Multiple compliance pathways based on component identification (three distinct categories in Requirement 2)","Cross-references to external technical documents (Aerospatiale Service Bulletin Stampe No 1, Rollason Modifications WAR 210 issues 1 and 2, UK CAA Emergency AD 011-03-88)","Technical aviation terminology requiring specialist knowledge (e.g., \"rolled threads,\" \"magnetic particle inspection,\" \"BSF\" thread standard)","Time-based compliance triggers (100 hours, 500 hours, component time in service) with conditional logic","Nested sub-paragraphs (2(b)(i) and (ii)) creating branching decision tree for compliance"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Stampe SV4 biplanes to inspect and, where necessary, replace the lower mainplane centre section tie rods — the critical wing‑holding rods — after a UK fatal crash caused by metal fatigue. It mandates urgent inspection before flight for some aircraft and sets retirement intervals by rod type (factory rods ~500 hrs, aftermarket ~100 hrs; unknown/damaged rods replaced immediately)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods","history":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods/history","analysis":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods/analysis","conflicts":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods/conflicts","importantCases":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods/important-cases","documents":"/api/acts/ad-sv4-1-amdt-1-lower-mainplane-centre-section-tie-rods/documents"}}