{"id":"F2008L00498","name":"AD/J4100/9 - Flap Nacelle Fairing Attachment","slug":"ad-j4100-9-flap-nacelle-fairing-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119323,"registerId":"commonwealth-F2008L00498-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/J4100/9 | Flap Nacelle Fairing Attachment | 4/2008 DM |\n| ---------- | ------------------------------- | --------- |\n\n| Applicability: | All Model Jetstream 4100 Series aircraft that are pre-modifications JM41575B and JM41575C.                                                                                                         |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with BAe Regional Aircraft Alert Service Bulletin (SB)J41-A57-015 Revision 1 or Revision 2, or later CAA/EASA approved revision.Note: UK CAA AD 006-05-96 refers.             |\n| Compliance:    | Upon accumulating 1500 flight hours, and thereafter at intervals not to exceed 1500 flight hours; until accomplishment of SB J41-57-017 (modification JM41575A).                                   |\n|                | This Airworthiness Directive becomes effective on 20 February 2008.                                                                                                                                |\n| Background:    | Reports were received of cracks in the angles and the skin that attach the flap nacelle fairing to the flap. Cracks in the attachment structure could cause loss of the fairing from the aircraft. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n15 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/9","sectionType":"part","heading":"AD/J4100/9","content":"## AD/J4100/9","sortOrder":1},{"sectionNumber":"Flap Nacelle Fairing Attachment","sectionType":"part","heading":"Flap Nacelle Fairing Attachment","content":"## Flap Nacelle Fairing Attachment","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety-of-flight issue (structural cracking). It has not expanded beyond its original purpose of mandating repetitive inspections for a known defect until a permanent modification is applied."},"complexity_factors":["Single, specific mechanical issue (flap nacelle fairing cracks)","Only 2 defined applicability conditions (aircraft model and pre-modification status)","Straightforward compliance timeline (1500 flight hour intervals)","Single cross-reference to manufacturer service bulletin","No nested exceptions or conditional logic — inspection required until modification performed","Short document (approximately 200 words of substantive content)"],"plain_english_summary":"Owners and operators of BAe Jetstream 4100 series aircraft must carry out recurring inspections of the flap nacelle fairing attachment per BAe Service Bulletin J41-A57-015 because cracks have been found in the brackets and skin that could allow the fairing to detach in flight. \n\nInspections are required every 1,500 flight hours until the permanent modification JM41575A is installed; aircraft with mods JM41575B/C are excluded."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive confines measures to pre-modification Jetstream 4100 aeroplanes to detect and repair cracks in the flap nacelle fairing attachment and imposes interim inspections until modification JM41575A is accomplished. It adheres to the original safety objective reported in the Background and does not expand scope beyond those aircraft or actions specified (Applicability; Background; Compliance)."},"complexity_factors":["Limited technical scope: targets a single structural attachment area (Background).","Applicability requires fleet-status checks to identify aircraft pre-mod JM41575B and JM41575C (Applicability).","Mandated action refers to external documents (BAe SB J41-A57-015 Rev 1/2 or later CAA/EASA-approved revision), creating dependency on approved revisions (Requirement).","Recurring compliance interval imposes repeated inspections every 1,500 flight hours until modification JM41575A is done, creating ongoing operational and scheduling burden (Compliance).","Cross-reference to related modification JM41575A creates a compliance pathway either by repeated inspection or by completing a modification (Compliance).","Effective date and enforcement are fixed (becomes effective 20 February 2008), requiring retrospective administrative tracking from that date (Compliance).","Potential repair/rectification actions are not detailed in the AD and sit in the referenced SB, requiring technical interpretation and parts/work by maintenance organisations (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of BAe Jetstream 4100 aircraft (those without modifications JM41575B or JM41575C) to inspect and act on the flap nacelle fairing attachment per BAe Service Bulletin J41-A57-015 (approved revisions). Inspections recur every 1,500 flight hours until the permanent modification JM41575A is installed; the rule is intended to find and fix cracks that could let the fairing detach and became effective 20 February 2008."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment","history":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment/history","analysis":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment/analysis","conflicts":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment/conflicts","importantCases":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment/important-cases","documents":"/api/acts/ad-j4100-9-flap-nacelle-fairing-attachment/documents"}}