{"id":"F2006B10555","name":"AD/HS 748/20 Amdt 1 - Rear Pressure Bulkhead and Fin Attachment Fittings","slug":"ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116373,"registerId":"commonwealth-F2006B10555-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 748/20 Amdt 1 - Rear Pressure Bulkhead and Fin Attachment Fittings","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)  \n\nAIRWORTHINESS 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 revokes Airworthiness Directive (AD) AD/HS 748/20 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 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\nBritish Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes\n\nAD/HS 748/20\n\nAmdt 1\n\n  \n\nRear Pressure Bulkhead and Fin Attachment Fittings\n\n  \n8/2001\n\nApplicability: All HS 748 aircraft.\n\nRequirement: Inspect in accordance with BAE Systems Mandatory Service Bulletin HS748-53-49 Revision 2.\n\nNote 1: UK CAA AD 002-03-83 refers.\n\nNote 2: The inspection of certain fuselage fin attachment fittings are required by AD/HS 748/19.\n\nCompliance: As specified in the Approval part of the Requirement document.\n\nThis Airworthiness Directive becomes effective on 9 August 2001.\n\nBackground: A structural audit carried out by British Aerospace indicated that the fin attachment fittings require regular inspections to ensure the continuing airworthiness of the HS 748 aircraft.\n\nAmendment 1 is issued in response to a revision of the Requirement document, which introduces the requirement to inspect other areas for fatigue damage while the fin is removed, and also to replace a number of items and return them to BAE Systems Regional Aircraft for detailed examination. Additionally, the revision provides clarification to repeat inspection instructions and the eddy current technique.\n\n![Signature of David Villiers](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 3 July 2001\n\n![](image.001.png)\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 July 2001.\n\n  \n\nPage 1 of 1","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment slightly expands the original directive by adding requirements to inspect additional areas for fatigue damage while the fin is removed, and to replace and return certain components to the manufacturer. However, this remains within the original safety purpose of ensuring structural integrity of the rear fuselage and tail attachment area. The scope has not fundamentally shifted from aircraft structural safety."},"complexity_factors":["Short, single-page document with straightforward structure","Only 2 defined references (the service bulletin and another AD), both external documents","Simple conditional logic: 'all aircraft of this type must comply'","No nested exceptions or complex definitional sections","Heavy reliance on external technical documents (the service bulletin) for actual implementation details — the AD itself is essentially a pointer to engineering specifications"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners, operators and maintainers of British Aerospace HS 748 aircraft in Australia to carry out detailed and recurring inspections of the rear pressure bulkhead and fin attachment fittings due to potential fatigue that could cause tail separation or loss of cabin pressure. Work must follow BAE Systems Mandatory Service Bulletin HS748‑53‑49 Rev 2, include extra checks and component replacements while the fin is removed, and return certain parts to the manufacturer. The directive took effect 9 August 2001."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the original AD by requiring inspections of additional fuselage areas when the fin is removed, mandates replacement of certain items with return to BAE Systems for detailed examination, and clarifies repeat inspection instructions and the eddy-current inspection technique. These changes broaden operator obligations beyond the original inspection focus."},"complexity_factors":["Reference to an external mandatory service bulletin for procedural detail (BAE Systems HS748-53-49 Rev 2)","Amendment adds inspections of additional areas that occur only when the fin is removed (increases scope of work and labour/time)","Requirement to replace certain items and return them to the manufacturer for detailed examination (logistics, shipping, custody, possible costs)","Clarification of repeat inspection intervals and a specific non-destructive test method (eddy current) introduces technical inspection standards","Compliance timing is delegated to the Approval part of the Requirement document rather than specified directly in the AD (dependency on another document for deadlines)","Cross-reference to related AD/HS 748/19 and UK CAA AD 002-03-83 creates interlocking compliance obligations"],"plain_english_summary":"This Airworthiness Directive requires all British Aerospace (Hawker Siddeley) HS 748 aircraft to have the rear pressure bulkhead and fin attachment fittings inspected per BAE Systems Mandatory Service Bulletin HS748-53-49 Revision 2. Operators must perform the inspections (including extra checks when the fin is removed), may need to replace items and return parts to BAE for detailed examination, and must meet timing and repeat-inspection requirements set out in the Requirement document."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings","history":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings/history","analysis":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings/analysis","conflicts":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings/conflicts","importantCases":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings/important-cases","documents":"/api/acts/ad-hs-748-20-amdt-1-rear-pressure-bulkhead-and-fin-attachment-fittings/documents"}}