{"id":"F2006B10423","name":"AD/HS 125/143 Amdt 1 - Addition of Vents and Pressure Relief Device","slug":"ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116109,"registerId":"commonwealth-F2006B10423-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/143 Amdt 1 - Addition of Vents and Pressure Relief Device","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)  \nBritish Aerospace BAe 125 Series Aeroplanes\n\nAD/HS 125/143\n\nAmdt 1\n\n  \nAddition of Vents and Pressure Relief Device 11/94\n\nApplicability: Model BAe 125 Series 1000A and 1000B and Hawker 1000.\n\nRequirement: 1. Action in accordance with Hawker Raytheon Corporate Jets Mandatory Service Bulletin 53-76-3627A.\n\n    2. Action in accordance with Hawker Raytheon Corporate Jets Mandatory Service Bulletin 53-81-3661B.\n\n    3. Action in accordance with Hawker Raytheon Corporate Jets Mandatory Service Bulletin 21-151-25A683C.\n\nCompliance: Prior to 31 March 1995.\n\nBackground: The manufacturer and the UK CAA require certain actions to be taken to ensure the structural integrity of the aircraft, in the event of an explosive decompression.\n\nAmendment 1 is issued in response to an additional modification requirement which has taken the manufacturer time to develop. As this modification requires minimal removal of furnishings for access, the UK CAA has imposed the same compliance time.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment stays within the original scope of the airworthiness directive. It simply adds one additional required modification while maintaining the same compliance deadline. The original purpose was to ensure structural integrity during explosive decompression through specific modifications; Amendment 1 continues this same safety purpose without expanding into new regulatory areas."},"complexity_factors":["Very short document (under 200 words)","Only 3 specific technical requirements, all referencing external manufacturer documents","No defined terms section","Simple conditional structure: single deadline applies to all requirements","No nested exceptions or complex cross-referencing within the instrument itself","Relies entirely on external technical documents (service bulletins) for actual implementation details"],"plain_english_summary":"This airworthiness directive mandates owners/operators of BAe 125 Series 1000A, 1000B and Hawker 1000 aircraft in Australia to install additional vents and pressure‑relief devices per three manufacturer service bulletins, completed by 31 March 1995.  \n\nThese modifications guard the airframe against damage from explosive decompression. Amendment 1 adds one extra, minor modification the manufacturer developed but keeps the original compliance deadline."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the original directive by adding an additional modification requirement developed by the manufacturer. The compliance mechanism remains the same (action via three Hawker Raytheon Mandatory Service Bulletins) and the deadline is unchanged, but the set of required modifications has increased."},"complexity_factors":["Narrow applicability: specific to BAe 125 Series 1000A/1000B and Hawker 1000 models, limiting operational scope.","Delegation to manufacturer documents: compliance requires following three external Hawker Raytheon Mandatory Service Bulletins rather than technical steps in the directive itself.","Fixed compliance deadline (prior to 31 March 1995) creates scheduling and logistics pressure for operators.","Amendment introduces an additional modification requirement developed after the original AD, requiring operators to incorporate the new step.","Minimal physical access requirement (limited removal of furnishings) reduces on-aircraft complexity but still requires workplace coordination.","Regulatory coordination: CASA action references UK CAA and manufacturer determinations, adding inter-authority reliance rather than independent technical specification in the AD."],"plain_english_summary":"This airworthiness directive requires owners/operators of British Aerospace BAe 125 Series 1000A/1000B and Hawker 1000 aircraft to carry out specified installations of vents and a pressure‑relief device by following three Hawker Raytheon mandatory service bulletins, completed by 31 March 1995. CASA issued the requirement at the manufacturer’s and UK CAA’s request to protect structural integrity in the event of explosive decompression. Operators pay for the work and must schedule access and minor furnishing removal to comply within the deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device","history":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device/history","analysis":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device/analysis","conflicts":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device/conflicts","importantCases":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device/important-cases","documents":"/api/acts/ad-hs-125-143-amdt-1-addition-of-vents-and-pressure-relief-device/documents"}}