{"id":"F2006B10951","name":"AD/JETSTREAM/80 - Elevator Bias Spring Assembly Bearing","slug":"ad-jetstream-80-elevator-bias-spring-assembly-bearing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56518,"registerId":"commonwealth-F2006B10951-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/80 - Elevator Bias Spring Assembly Bearing","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/80 Elevator Bias Spring Assembly Bearing 13/98\n\nApplicability: All Jetstream Series 3100 and Series 3200 aircraft.\n\nRequirement: Action in accordance with BAe Regional Aircraft Mandatory Service Bulletin (SB) 27-A-JA980606 Revision 1.\n\nNote: On aircraft with SB 27-A-JA980606 (original issue) incorporated, no further action is required.\n\nCompliance: Unless already accomplished, before 31 January 1999.\n\nThis Airworthiness Directive becomes effective on 3 December 1998.\n\nBackground: The manufacturer received a report from an operator of the detachment of the link that connects the bias spring to the elevator quadrant in the elevator control system. The failed bearing is designed to accommodate only a limited amount of misalignment and the failure has been attributed to a twist force applied by the spring due to the incorrect orientation of the spring hook ends.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive stays within the original, technical safety purpose of addressing a reported bearing failure on Jetstream Series 3100/3200 aircraft. It requires incorporation of BAe’s specified service bulletin (Revision 1) and exempts aircraft that already have the original issue of that bulletin incorporated. Nothing in the AD text expands the class of affected aircraft or adds unrelated obligations beyond remediation of the elevator bias spring assembly bearing issue (Applicability; Requirement; Note; Background)."},"complexity_factors":["Narrow technical scope: applies only to BAe Jetstream Series 3100 and 3200 (Applicability)","Mandates compliance with a single manufacturer service bulletin rather than specifying detailed technical steps in the AD text (Requirement)","Short, fixed compliance window and effective date create a time-sensitive obligation (Compliance; effective date)","Technical subject-matter (mechanical bearing, spring orientation) requires qualified maintenance personnel to implement the SB (Background; Requirement)","Exception for aircraft already modified by the original SB adds a simple conditional compliance rule (Note)","Dependence on an external document (SB 27-A-JA980606 Revision 1) for the exact remedial procedure increases procedural dependency"],"plain_english_summary":"Owners/operators of British Aerospace Jetstream Series 3100 and 3200 must carry out the work specified in BAe Mandatory Service Bulletin 27-A-JA980606 Rev 1 to address a reported detachment/twist failure of the elevator bias-spring link. The AD is effective 3 Dec 1998 and, unless already done (original SB incorporated), required work must be completed by 31 Jan 1999. Compliance costs and downtime fall to the aircraft owners/operators."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete airworthiness directive addressing a specific safety defect in specific aircraft. It has not expanded beyond its original purpose of mandating a particular mechanical fix."},"complexity_factors":["Single, specific mechanical issue addressed","Only one substantive requirement (comply with referenced service bulletin)","Clear applicability (two specific aircraft series)","Simple compliance condition (already done or do by date)","No nested definitions, cross-references to other legislation, or conditional exceptions","Self-contained document with minimal regulatory machinery"],"plain_english_summary":"This is a **safety order for specific aircraft** — the British Aerospace Jetstream 3100 and 3200 series planes.\n\n**What it does:**\nIt requires airlines and aircraft operators to inspect and fix a specific mechanical problem in the elevator control system (the part that helps control the plane's up-and-down movement). The issue involves a bearing in the \"bias spring assembly\" — a component that helps return the elevator to a neutral position.\n\n**The problem:**\nA bearing was failing because a spring was installed incorrectly, creating twisting forces it wasn't designed to handle. This caused at least one case where a connecting link detached from the elevator system — a serious flight safety risk.\n\n**Who must act:**\nAnyone operating Jetstream 3100 or 3200 aircraft.\n\n**What they must do:**\nFollow the manufacturer's specific repair instructions (Service Bulletin 27-A-JA980606 Revision 1). If they already applied the original version of this fix, they don't need to do anything further.\n\n**Deadline:**\nThe fix must be completed by 31 January 1999 (unless already done).\n\n**Why it matters:**\nElevator control failures can lead to loss of aircraft control. This directive prevents potential accidents by ensuring a known mechanical defect is corrected before it causes an in-flight emergency."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing","history":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing/history","analysis":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing/analysis","conflicts":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing/conflicts","importantCases":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing/important-cases","documents":"/api/acts/ad-jetstream-80-elevator-bias-spring-assembly-bearing/documents"}}