{"id":"F2008L00508","name":"AD/J4100/19 - Vertical and Horizontal Stabiliser Attachment Fittings","slug":"ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119353,"registerId":"commonwealth-F2008L00508-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"BAe Systems (Operations) Jetstream 4100 ","sectionType":"division","heading":"BAe Systems (Operations) Jetstream 4100 Series Aeroplanes","content":"### BAe Systems (Operations) Jetstream 4100 Series Aeroplanes\n\n| AD/J4100/19 | Vertical and Horizontal Stabiliser Attachment Fittings | 4/2008 DM |\n| ----------- | ------------------------------------------------------ | --------- |\n\n| Applicability: | All Model Jetstream Series 4100 aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with BAE Systems Mandatory Service Bulletin J41-55-012 Revision 1, or later CAA/EASA approved revision.Note: UK CAA AD 005-10-2002 refers.                                                                                                                                                                                                                                                                                                               |\n| Compliance:    | Unless the initial inspection is already accomplished, within 30 days after20 February 2008. If J41-55-011 Part 1 was complied with then the initial inspection requirements have been satisfied. If operators have removed the horizontal stabiliser and have carried out detail visual inspections of the attachment fitting lugs and eye bolt shanks, then the initial inspection requirements have been satisfied. Inspect thereafter at intervals not to exceed 8 years. |\n|                | This Airworthiness Directive becomes effective on 20 February 2008.                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | Fretting corrosion has been found during inspection of the horizontal and vertical stabiliser attachment fittings on aircraft in service. This fretting corrosion has been found on the horizontal and vertical stabiliser forward and rear attachment fitting lug contact faces. Corrosion has also been found on the eye bolt shanks. A dedicated inspection is required to maintain structural integrity.                                                                  |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n15 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/19","sectionType":"part","heading":"AD/J4100/19","content":"## AD/J4100/19","sortOrder":1},{"sectionNumber":"Vertical and Horizontal Stabiliser Attac","sectionType":"part","heading":"Vertical and Horizontal Stabiliser Attachment Fittings","content":"## Vertical and Horizontal Stabiliser Attachment Fittings","sortOrder":2},{"sectionNumber":"4/2008 DM","sectionType":"part","heading":"4/2008 DM","content":"## 4/2008 DM","sortOrder":3}],"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies specifically to all Model Jetstream Series 4100 aircraft and mandates inspections per a BAE service bulletin. It references prior ADs/inspections as satisfying the initial requirement but does not expand the population or materially alter the subject matter beyond requiring the dedicated inspections for identified corrosion risks."},"complexity_factors":["Technical subject‑matter: inspection for fretting corrosion on fittings and eye‑bolt shanks requires specialist maintenance knowledge and access to structural components (Background; Requirement).","Reliance on external document: mandatory action is defined by BAE Systems Mandatory Service Bulletin J41‑55‑012 and any later CAA/EASA‑approved revisions (Requirement).","Regulatory approvals: actions must follow the approved revision, so compliance depends on availability and content of that approved document (Requirement).","Fixed short deadline for initial compliance: initial inspection within 30 days after 20 February 2008 creates near‑term scheduling pressure for operators (Compliance).","Dependency on prior work: compliance is affected if J41‑55‑011 Part 1 was already complied with or if the horizontal stabiliser was removed for detailed inspection (Compliance).","Recurring obligation: inspections thereafter at intervals not to exceed 8 years impose ongoing maintenance planning (Compliance).","Operational disruption risk: detailed visual inspection may require removal of the horizontal stabiliser, increasing labour, downtime and cost (Compliance).","Limited scope but precise applicability: applies to all Model Jetstream Series 4100 aircraft only, narrowing who must act but requiring fleet‑by‑fleet verification (Applicability)."],"plain_english_summary":"This Airworthiness Directive requires operators of all BAe Jetstream 4100 series aeroplanes to inspect the vertical and horizontal stabiliser attachment fitting lugs and eye‑bolt shanks in accordance with BAE Systems Mandatory Service Bulletin J41‑55‑012 (or later CAA/EASA‑approved revision). It responds to detected fretting corrosion and is intended to protect structural integrity (Requirement; Background). Initial inspections must be completed within 30 days after 20 February 2008 (unless earlier work already satisfied the requirement) and must be repeated at intervals not exceeding eight years (Compliance). Operators pay compliance costs and must follow approved revisions."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific structural corrosion issue on a single aircraft type. There is no evidence of scope creep; it targets exactly the safety problem identified in the background (fretting corrosion on stabiliser fittings) and mandates precisely the inspection regime required to address it."},"complexity_factors":["Single, specific mechanical issue (stabiliser attachment fittings)","Only one primary compliance pathway (follow the BAE Systems service bulletin)","Simple conditional logic (two exemption clauses for operators who already did equivalent inspections)","No defined terms section or extensive cross-referencing to other legislation","Short, self-contained document with clear applicability and compliance dates"],"plain_english_summary":"CASA requires operators of BAe Jetstream 4100 aircraft to inspect the vertical and horizontal stabiliser attachment fittings for fretting corrosion, following BAE Systems Mandatory Service Bulletin J41‑55‑012 (or later). Initial inspection was due within 30 days of 20 Feb 2008 (unless already done) and must be repeated every 8 years. This addresses wear that can weaken the tail-to-fuselage connection and jeopardise structural integrity and flight safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings","history":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings/history","analysis":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings/analysis","conflicts":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings/conflicts","importantCases":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings/important-cases","documents":"/api/acts/ad-j4100-19-vertical-and-horizontal-stabiliser-attachment-fittings/documents"}}