{"id":"F2008L00510","name":"AD/J4100/21 - Fatigue and Environmental Damage Inspections","slug":"ad-j4100-21-fatigue-and-environmental-damage-inspections","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119360,"registerId":"commonwealth-F2008L00510-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/J4100/21 | Fatigue and EnvironmentalDamage Inspections | 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 J41-51-001 Revision 2, or later CAA/EASA approved revision.Note: UK CAA AD 005-02-2002 refers.                                                                                                                                                                                                                                                                                                                                                                               |\n| Compliance:    | As specified in paragraph M. (Approval) Appendices 1 through 5 of the Requirement document for the initial thresholds and repeat inspection intervals.                                                                                                                                                                                                                                                                                                                                                                                        |\n|                | This Airworthiness Directive becomes effective on 20 February 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | An extensive review of the mainframe fatigue test results and the MSG-3 analysis for the Jetstream 4100 has been completed. The review has identified new inspections and revisions to existing inspections (requirements and inspection thresholds). This service bulletin introduces appropriate mandatory inspections to maintain the structural integrity of the airframe. It will be superseded when the aircraft maintenance manual, maintenance review board report and the maintenance planning document are revised at a later date. |\n\n  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n15 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/21","sectionType":"part","heading":"AD/J4100/21","content":"## AD/J4100/21","sortOrder":1},{"sectionNumber":"Fatigue and Environmental Damage Inspect","sectionType":"part","heading":"Fatigue and Environmental Damage Inspections","content":"## Fatigue and Environmental  \nDamage Inspections","sortOrder":2},{"sectionNumber":"4/2008 DM","sectionType":"part","heading":"4/2008 DM","content":"## 4/2008 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"The AD expands and revises the existing inspection regime: it introduces new inspections and updates inspection thresholds and intervals following a mainframe fatigue review. These mandatory measures apply to all Jetstream 4100 aircraft until the aircraft maintenance manual, maintenance review board report and maintenance planning document are formally revised and the AD is superseded (Background; Requirement)."},"complexity_factors":["Technical inspection requirements and thresholds specified in Appendices 1–5 create inspection planning and engineering judgement demands (Compliance: 'paragraph M. (Approval) Appendices 1 through 5 of the Requirement document').","Dependence on an external mandatory service bulletin and later CAA/EASA‑approved revisions requires operators to track and incorporate external documents (Requirement: 'Action in accordance with BAE Systems Mandatory Service Bulletin J41-51-001 Revision 2, or later CAA/EASA approved revision.').","Applicability to the entire Jetstream 4100 fleet broadens operational impact and aggregate cost (Applicability: 'All Model Jetstream Series 4100 aircraft.').","Fixed effective date and recurring‑interval obligations impose scheduling, maintenance and record‑keeping burdens from 20 February 2008 (Compliance: 'This Airworthiness Directive becomes effective on 20 February 2008.').","Temporary transitional scope—to be superseded when AMM/MRB/MPD are revised—creates short‑ to medium‑term regulatory uncertainty for maintenance planners (Background: 'It will be superseded when the aircraft maintenance manual, maintenance review board report and the maintenance planning document are revised at a later date.').","Formal AD issuance by the CASA delegate creates a legally enforceable obligation, concentrating decision authority with the regulator (signature block: 'Delegate of the Civil Aviation Safety Authority').","Requirement that later revisions be CAA/EASA approved means additional administrative interactions with certification authorities for changes (Requirement: reference to 'CAA/EASA approved revision')."],"plain_english_summary":"Mandates new fatigue and environmental‑damage inspections for all BAe Jetstream 4100 series aircraft. Operators must carry out inspections in accordance with BAE Systems Mandatory Service Bulletin J41‑51‑001 Rev 2 (or a later CAA/EASA‑approved revision) and follow initial thresholds and repeat intervals set in the Requirement document’s Appendices 1–5; the AD is effective 20 February 2008 (Requirement; Compliance; Effective date). It implements changes identified by a fatigue review to maintain airframe structural integrity (Background). Operators pay inspection costs and must schedule recurring work."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This instrument maintains its original narrow scope. It was issued specifically to mandate fatigue and environmental damage inspections for the Jetstream 4100 following engineering reviews, and it continues to serve that single purpose without expansion into unrelated operational or certification matters."},"complexity_factors":["Short, single-purpose instrument (approximately 250 words)","Only 1 defined term implicitly used ('Model Jetstream Series 4100 aircraft')","Minimal conditional logic — essentially one requirement with compliance timing delegated to an external technical document","Heavy reliance on external technical reference (BAE Systems Service Bulletin) without reproducing its contents","No nested exceptions or elaborate cross-referencing within the instrument itself","Standardised AD format with predictable structure (Applicability, Requirement, Compliance, Background)"],"plain_english_summary":"This AD requires owners and operators of BAe Jetstream 4100 series aircraft to carry out mandated structural inspections per BAE Systems Mandatory Service Bulletin J41-51-001 Rev 2 (or later) to detect fatigue cracks and environmental corrosion. Effective 20 February 2008, inspections start and recur based on aircraft age/flight hours. It’s a temporary safety measure until the checks are incorporated into the aircraft maintenance manuals."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections","history":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections/history","analysis":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections/analysis","conflicts":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections/conflicts","importantCases":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections/important-cases","documents":"/api/acts/ad-j4100-21-fatigue-and-environmental-damage-inspections/documents"}}