{"id":"F2006B10431","name":"AD/HS 125/150 Amdt 1 - Main Landing Gear - Sidestay Jack Pivot","slug":"ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116125,"registerId":"commonwealth-F2006B10431-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/150 Amdt 1 - Main Landing Gear - Sidestay Jack Pivot","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  British Aerospace BAe 125 Series Aeroplanes\n\n \n\n# AD/HS 125/150\n\nAmdt 1\n\nApplicability: All models.\n\n# Main Landing Gear - Sidestay Jack Pivot 6/96\n\n \n\nRequirement: 1. a. Visually inspect the left and right main landing gear sidestay jack pivot assemblies to identify bushes with eccentric bores.\n\n \n\n1.  b. Inspect jack pivot assemblies with eccentric bores for cracks, using magnetic particle method as per CAO 108.8. Inspect in the area defined in Detail A of the diagram on page 10 of Hawker SB 32-233 Revision 1.\n\n\n \n\nNote: It has been found that some aircraft technical records may not correctly show the modification status of the jack pivot. Hawker Service Bulletin (SB) 32-233 Revision 2 and CAA(UK) AD 007-06-94 refer.\n\n \n\n2.    Replace jack pivot assembly, P/N 25UM1199A, 25UM1229A or 25UM87-1A, with P/N 25UM1335-1A or P/N 25-8UM173-1A.\n\n \n\n3.    Replace jack pivot assemblies P/N 25UM1199A, 25UM1229A or 25UM87-1A, that have been installed new after 23 June 1994, in accordance with Hawker SB 32-233-3597A. Replace with jack pivot assembly P/N 25UM1335-1A or P/N 25- 8UM173-1A.\n\n \n\nCompliance:  1. Initially inspect before 3000 landings since sidestay assembly was new, before 1000 landings since overhauled or before 23 May 1996, whichever occurs last. Re-inspect assemblies with eccentric bores at intervals not to exceed:\n\n \n\n1. 1000 landings, if no cracks are found, or;\n\n\n \n\nb.    100 landings, if cracks are found which are within the serviceable limits specified in Hawker SB 32-233 Revision 2, Paragraph 2.B.(6)(c)\n\n \n\n2.    Replace assembly before 4000 landings or at the next 4000 landing overhaul, whichever occurs later.\n\n \n\n3.    Replace assembly before 2000 landings or 20 June 1996, whichever occurs later.\n\n \n\nCompliance with Hawker SB 32-233-3597A cancels all requirements of this directive.\n\n \n\nThis amendment is effective 23 May 1996.\n\n \n\nBackground:  A report has been received of a fractured jack pivot assembly, which resulted in the main landing gear failing to deploy for landing. As the visual inspection in Hawker SB 32-233 is considered ineffective a magnetic particle inspection is specified.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\nThis amendment requires the replacement of new sidestay jack pivot assemblies issued after 23 June 1994. Some parts issued after this time are considered suspect, resulting in lower fatigue life. The particular parts cannot be identified due to the absence of batch or serial numbers. Earlier parts are not affected and are still acceptable if inspected as required.\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment extended the directive to require mandatory replacement of sidestay jack pivot assemblies issued after 23 June 1994 (those parts are treated as suspect). It also prescribes magnetic-particle inspection, sets specific inspection intervals and replacement deadlines for assemblies, and states that compliance with Hawker SB 32-233-3597A cancels the AD. Earlier parts remain acceptable if inspected as required."},"complexity_factors":["Multiple technical inspection methods: initial visual check plus mandatory magnetic-particle inspection for suspect bores increases shop capability and labour time.","Part-number specificity: several old P/Ns must be replaced with specified new P/Ns (e.g. replace 25UM1199A/25UM1229A/25UM87-1A with 25UM1335-1A or 25-8UM173-1A) — requires accurate parts tracking.","Date- and event-based triggers: different compliance thresholds tied to 'landings since new', 'since overhaul' and fixed calendar dates create record-keeping complexity.","Conditional re-inspection intervals: shorter intervals (100 landings) apply if limited cracking is found versus 1000 landings if clear — requires judgement and ongoing monitoring.","Traceability gap: suspect parts issued after 23 June 1994 cannot be identified by batch/serial numbers, making enforcement and parts-recall decisions administratively harder.","Dependency on external documents: references to Hawker Service Bulletin revisions and CAA(UK) AD affect requirements; complying with Hawker SB 32-233-3597A cancels the AD, creating mutual dependence between documents."],"plain_english_summary":"Requires operators of British Aerospace BAe 125/150 aircraft to inspect and, where necessary, replace main landing gear sidestay jack pivot assemblies. It mandates visual and magnetic-particle inspections for eccentric bores and cracks, sets specific inspection intervals and replacement deadlines, and identifies parts issued after 23 June 1994 as suspect. Compliance with a specified Hawker service bulletin cancels the directive. Operators and maintenance organisations pay for inspections, repairs and replacements."},"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":4,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment adds requirement 3 to address newly identified suspect parts issued after 23 June 1994, but this is a targeted expansion to address the same underlying safety issue (jack pivot fatigue/cracking). The scope remains tightly focused on the specific mechanical defect in the main landing gear sidestay jack pivot assemblies of BAe 125 aircraft."},"complexity_factors":["Multiple compliance pathways based on three different variables: landings since new, landings since overhaul, and calendar dates (whichever occurs last/later)","Nested conditional logic: different re-inspection intervals (100 vs 1,000 landings) depending on inspection findings","Cross-references to external documents: Hawker Service Bulletin 32-233 (multiple revisions), CAO 108.8 (magnetic particle inspection standard), and CAA(UK) AD 007-06-94","Part number specificity: requires tracking of five different part numbers (25UM1199A, 25UM1229A, 25UM87-1A, 25UM1335-1A, 25-8UM173-1A) with different replacement rules based on installation date","Cancellation clause: compliance with a specific service bulletin (SB 32-233-3597A) cancels all other requirements, creating an alternative compliance path"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of BAe 125/Hawker 800 series jets to address a defective sidestay jack pivot in the main landing gear: some replacement pivots made after June 1994 may have reduced fatigue life and can crack, risking gear non‑deployment. \n\nIt mandates inspections (including magnetic particle testing for eccentric bores), repeat checks tied to landing cycles, and replacement with improved parts by specified deadlines to prevent catastrophic landing‑gear failures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot","history":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot/history","analysis":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot/analysis","conflicts":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot/conflicts","importantCases":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot/important-cases","documents":"/api/acts/ad-hs-125-150-amdt-1-main-landing-gear-sidestay-jack-pivot/documents"}}