{"id":"F2006B10937","name":"AD/JETSTREAM/67 - Wing - Fuselage Forward Attachment Spigot Bushes Migration","slug":"ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56487,"registerId":"commonwealth-F2006B10937-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/67 - Wing - Fuselage Forward Attachment Spigot Bushes Migration","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBritish Aerospace BAe 3100 (Jetstream) Series Aeroplanes\n\nAD/JETSTREAM/67 Wing \\- Fuselage Forward Attachment\n\nSpigot Bushes Migration\n\n  \n10/94\n\nApplicability: All HP137 Mk1 aircraft and all Jetstream series 3100 aircraft with constructor’s numbers in the range 601 to 702 inclusive.\n\nRequirement: 1. Visually inspect the outboard bush in the spigot post assembly, on both the left and right hand sides, to determine if the bush has migrated inboard in accordance with British Aerospace SB 57-A-JA 920640 Fig 1 and Part 1.\n\n2. Install modified one piece bush in accordance with British Aerospace SB 57-A-JA- 920640 Part 2.\n\nCompliance: 1. Inspect within 1200 landings after 15 September 1994.\n\nRepeat inspections as detailed below:\n\nNo bush migration 6000 Landings Bush migration less than 0.5\" 1200 Landings\n\n2. Modify within 200 landings if bush migration is more than 0.5\" Installation of one piece bush cancels the inspection requirement of this AD.\n\nBackground: The outboard one piece bush on an in-service aircraft was found to have migrated inboard and come to rest against the mainplane spigot housing plate. This may result in a redistribution of the loads in the wing and result in a reduced fatigue life.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific mechanical defect in a limited fleet of aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Short, single-purpose directive with clear mechanical focus","Only 2 defined aircraft applicability ranges (HP137 Mk1 and Jetstream 3100 serials 601-702)","Simple conditional logic: three possible inspection outcomes with different repeat intervals","Single cross-reference to external technical document (British Aerospace Service Bulletin 57-A-JA-920640)","No nested definitions or legislative interpretation sections","Clear compliance timeline with landings-based rather than calendar-based deadlines"],"plain_english_summary":"This mandatory CASA AD requires owners/operators of HP137 Mk1 and Jetstream 3100 (S/N 601–702) to inspect the wing-to-fuselage attachment bush for inward migration and, if it has moved more than 0.5\", fit a redesigned one-piece bush (short-term corrective action). Migration alters load paths and can shorten wing fatigue life, so recurring inspections are required when migration is absent or minor; the one-piece bush removes the need for further checks."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument itself states applicability and corrective actions without referencing prior amendments or a change of scope. There is no indication within this AD that its scope differs from the original directive as published here."},"complexity_factors":["Limited applicability by specific aircraft models and constructor numbers (Applicability).","Measurement threshold for action (migration > 0.5\") requires accurate visual assessment (Requirement; Compliance).","Timing tied to landing counts (inspect within 1200 landings, repeat intervals, modify within 200 landings) creates scheduling constraints for operators (Compliance).","Mandatory use of British Aerospace Service Bulletin procedures for inspection and installation creates procedural dependency (Requirement).","Replacement cancels inspection obligation, affecting maintenance planning and parts procurement (Requirement)."],"plain_english_summary":"This AD requires operators of HP137 Mk1 and Jetstream 3100 aircraft (constructor numbers 601–702) to inspect the outboard spigot post bush for inward migration and to install a modified one-piece bush where required. Migration can alter wing load distribution and reduce fatigue life (Background). Inspections and repeat intervals are specified by landing counts and the modified bush must be fitted within 200 landings if migration exceeds 0.5\"; installation cancels further inspections. Operators pay for inspections, maintenance scheduling and parts (Requirement; Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration","history":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration/history","analysis":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration/analysis","conflicts":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration/conflicts","importantCases":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration/important-cases","documents":"/api/acts/ad-jetstream-67-wing-fuselage-forward-attachment-spigot-bushes-migration/documents"}}