{"id":"F2008L00507","name":"AD/J4100/18 - Aft Fuselage Frames","slug":"ad-j4100-18-aft-fuselage-frames","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119350,"registerId":"commonwealth-F2008L00507-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/J4100/18 | Aft Fuselage Frames | 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 J41-53-051 Revision 1, or later CAA/EASA approved revision.Note: UK CAA AD 003-01-2002 refers.                                                                   |\n| Compliance:    | Unless the initial inspection is already accomplished, within 30 days after20 February 2008. Thereafter at intervals not to exceed 2 years.                                                                                       |\n|                | This Airworthiness Directive becomes effective on 20 February 2008.                                                                                                                                                               |\n| Background:    | Corrosion has been detected along the aft fuselage frames. The corrosion occurs on frame areas below floor panel level in the vicinity of the toilet, galley and rear baggage door due to the ingress of water / liquid spillage. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n15 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/18","sectionType":"part","heading":"AD/J4100/18","content":"## AD/J4100/18","sortOrder":1},{"sectionNumber":"Aft Fuselage Frames","sectionType":"part","heading":"Aft Fuselage Frames","content":"## Aft Fuselage Frames","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 targeting a specific safety issue (corrosion in aft fuselage frames) on a specific aircraft model. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only 1 defined term implicitly referenced (the service bulletin)","No cross-references to other legislation or complex conditional logic","Single straightforward compliance requirement with clear deadline","Simple binary applicability (all Model Jetstream Series 4100 aircraft)","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of Jetstream 4100 series aircraft to inspect the rear fuselage (frames near the toilet, galley and rear baggage door) for corrosion caused by water ingress.  \n\nCorrosion can weaken structure and create serious safety risks; compliance with the BAE Systems service bulletin is mandatory to maintain airworthiness."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive implements the stated remedial scope — detect and remedy corrosion on aft fuselage frames of all Jetstream 4100 series aircraft — by mandating inspections per the manufacturer’s service bulletin and setting compliance timing (Applicability; Requirement; Compliance; Background). It does not expand applicability beyond the aircraft series or broaden mandated actions beyond the service bulletin and approved revisions."},"complexity_factors":["Narrow scope: applies to a single aircraft family and a specific structural area (Applicability; Background).","Prescriptive remedy: delegates technical detail to a manufacturer service bulletin, reducing legal complexity but requiring technical compliance (Requirement).","Recurring compliance schedule: initial inspection deadline and fixed biennial intervals create ongoing operational burden (Compliance).","Reliance on external approvals: allows later CAA/EASA‑approved revisions of the service bulletin, creating dependence on regulator/manufacturer coordination (Requirement).","Safety‑critical technical assessment: inspection for corrosion may require specialised maintenance resources and possible repairs, raising direct cost and logistics for operators (Background)."],"plain_english_summary":"This Airworthiness Directive requires all BAe Jetstream Series 4100 aircraft to be inspected for corrosion on aft fuselage frames and to carry out whatever corrective actions the manufacturer’s Mandatory Service Bulletin J41-53-051 (or a later CAA/EASA‑approved revision) specifies (Applicability; Requirement). Inspections must begin within 30 days after 20 February 2008 if not already done and repeat every two years thereafter; operators bear inspection and repair costs and CASA enforces compliance (Compliance; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-18-aft-fuselage-frames","history":"/api/acts/ad-j4100-18-aft-fuselage-frames/history","analysis":"/api/acts/ad-j4100-18-aft-fuselage-frames/analysis","conflicts":"/api/acts/ad-j4100-18-aft-fuselage-frames/conflicts","importantCases":"/api/acts/ad-j4100-18-aft-fuselage-frames/important-cases","documents":"/api/acts/ad-j4100-18-aft-fuselage-frames/documents"}}