{"id":"F2006B06900","name":"AD/SD3-60/53 Amdt 4 - Engine Mounting Tubes and Fittings","slug":"ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114780,"registerId":"commonwealth-F2006B06900-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-60/53 Amdt 4 - Engine Mounting Tubes and Fittings","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/SD3-60/53 Amdt 3 and issues the following 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 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\n![](image.001.png)\n\nShort SD3-60 Series Aeroplanes\n\nAD/SD3-60/53\n\nAmdt 4\n\n  \nEngine Mounting Tubes and Fittings 3/2003\n\nApplicability: All SD3-60 aircraft that have not yet complied with Shorts Service Bulletin (SB) SD330- 71-18 or which are currently required to perform the 6 month repeat inspections in accordance with SB SD330-71-18 original issue, Revision 1, Revision 2, or Revision 3.\n\nNote: All aircraft that have complied with a previous issue of this Directive and determined that no corrosion exists, or have replaced all corroded engine tube sub- assemblies in accordance with Part B of a previous Requirement document, are not required to comply with Amendment 4 of this Directive.\n\nRequirement: Action in accordance with Shorts Service Bulletin SD360-71-20 or SD360-71-20 Revision\n\nNote: The Requirement document covers information contained in Service Information Letter 203, which will be cancelled.\n\nCompliance: Unless in compliance with the previous issue of this Directive, accomplish before 31 May 2003 or at the next required repeat inspection in accordance with SB SD330-71-18 original issue, Revision 1, Revision 2, or Revision 3; whichever occurs first.\n\nThis Amendment becomes effective on 20 March 2003.\n\nBackground: The manufacturer received reports of corrosion on the internal surface of the engine mounting tubes, tube end fittings, taper pins, and also on the foot fittings.\n\nAmendment 1 corrected fastener information in accomplishment instructions. Amendment 2 corrected ambiguities and errors in the Requirement document.\n\nAmendment 3 introduced a new Requirement document which superseded SB SD360-71- 18 at all issues.\n\nShort SD3-60 Series Aeroplanes\n\nAD/SD3-60/53 Amdt 4 (Continued)\n\nAmendment 4 is issued in response to a revision of the Requirement document which provides additional information on inspection for damage to the taper pin holes and installation of the taper pins.\n\nAmendment 3 of this Airworthiness Directive became effective on 28 November 2002. Amendment 2 of this Airworthiness Directive became effective on 23 March 2000.\n\nAmendment 1 of this Airworthiness Directive became effective on 22 April 1999.\n\nThe original issue of this Airworthiness Directive became effective on 25 March 1999.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 31 January 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The legislation maintains its original scope — addressing corrosion in engine mounting tubes of Short SD3-60 aircraft. While Amendment 4 adds detail about taper pin hole inspection and installation, this is a refinement of the existing safety requirement rather than an expansion into new operational areas."},"complexity_factors":["Multiple nested applicability conditions (compliance status with previous service bulletins and amendments)","Cross-references to 4 different versions of Service Bulletin SD330-71-18 and 2 versions of SD360-71-20","Dual compliance deadlines (calendar date vs. inspection cycle)","Exemption clause requiring verification of prior compliance status","Amendment history tracking (4 amendments since 1999) creating version control complexity"],"plain_english_summary":"Owners and operators of Short SD3-60 aircraft are required to inspect and, if necessary, repair engine mounting tubes and fittings because internal corrosion has been found. Aircraft already repaired under earlier actions are exempt.\n\nWork must follow Shorts Service Bulletin SD360-71-20 (or its revision) — including checks of taper pin holes and correct pin installation — to be done before 31 May 2003 or at the next scheduled inspection."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Amendment 4 refines the Requirement document by adding inspection and installation detail for taper pins but does not broaden which aircraft are covered. Applicability remains limited to SD3-60 aircraft not already compliant with the cited SB, and aircraft that previously complied with no corrosion or replaced corroded assemblies remain exempt (Applicability; Requirement; Background)."},"complexity_factors":["Cross-references to multiple service documents and amendment histories (Requirement references SD360-71-20; Applicability cross-references SB SD330-71-18 original and Revisions 1–3).","Conditional compliance and exemption language (aircraft that previously complied and found no corrosion, or have replaced corroded sub-assemblies, are excluded) (Applicability, Note).","Timing rule with a compound trigger ('before 31 May 2003 or at the next required repeat inspection... whichever occurs first') creates scheduling complexity for operators (Compliance).","Technical inspection specificity — adds inspection for taper-pin hole damage and taper-pin installation details — which may require specialised inspection skills and judgement (Background; Amendment 4 description).","Operational burden on operators from repeat six‑monthly inspections and potential parts replacement (Applicability; Compliance).","Multiple past amendments and supersessions to track (original AD plus Amendments 1–3 and this Amdt 4), increasing administrative/legal tracking costs (Background).","Reference to cancellation of related Service Information Letter increases document-control complexity (Requirement Note).","Delegation and enforcement mechanism under CAR 1998 subregulation 39.1(1) requires coordination with the Civil Aviation Safety Authority for compliance verification (preamble)."],"plain_english_summary":"This Airworthiness Directive requires operators of Short SD3-60 aeroplanes that have not already complied to inspect engine mounting tubes, tube end fittings, taper pins and foot fittings and to carry out any specified replacements or corrective work in accordance with Shorts Service Bulletin SD360‑71‑20 (and its revisions). It sets a compliance deadline (before 31 May 2003 or at the next scheduled six‑monthly repeat inspection) and was issued in response to reports of internal corrosion and to add inspection detail for taper‑pin holes and installation."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings","history":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings/history","analysis":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings/analysis","conflicts":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings/conflicts","importantCases":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings/important-cases","documents":"/api/acts/ad-sd3-60-53-amdt-4-engine-mounting-tubes-and-fittings/documents"}}