{"id":"F2006B09209","name":"AD/DHC-8/53 - Roll Disconnect System","slug":"ad-dhc-8-53-roll-disconnect-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53044,"registerId":"commonwealth-F2006B09209-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/53 - Roll Disconnect System","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\n \n\nAD/DHC-8/53 Roll Disconnect System 6/98\n\nApplicability: DHC-8 aircraft, Models 102, 103, 106, 201, 202, 301, 311, 314, and 315, with serial\n\nnumbers 3 through 433.\n\n \n\nRequirement: Install Modification 8/2376 in accordance with de Havilland Service Bulletin 8-27- 79, Revision A.\n\n \n\nNote: Transport Canada AD CF-98-04 refers.\n\n \n\nCompliance: Before 21 November 1998.\n\n \n\nThis airworthiness directive becomes effective on 21 May 1998.\n\n \n\nBackground: Several incidents have been reported of uncommanded roll system disconnects during landing.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope, as stated in the source, matches its stated purpose: it requires installation of a specific modification on identified DHC-8 models and serial numbers to address reported uncommanded roll disconnects (Applicability; Requirement; Background). It does not broaden applicability beyond the listed aircraft nor add requirements beyond the installation specified in the service bulletin."},"complexity_factors":["Narrow applicability limited to specific DHC-8 models and serial numbers (Applicability)","Single, discrete technical action required: install Modification 8/2376 (Requirement)","Compliance depends on an external technical document (de Havilland Service Bulletin 8-27-79, Revision A) which prescribes execution (Requirement)","Fixed, short compliance timeline between effective date and compliance date (This airworthiness directive becomes effective on 21 May 1998; Compliance)","Cross-reference to a foreign authority's AD (Transport Canada AD CF-98-04) adds an external regulatory cross-check (Note)"],"plain_english_summary":"What this directive requires\n\n- The Civil Aviation Safety Authority requires specified Bombardier (de Havilland/DHC-8) aeroplanes to be modified to the roll disconnect system by installing Modification 8/2376 (Requirement). The installation must follow de Havilland Service Bulletin 8-27-79, Revision A (Requirement).\n\nWho is affected\n\n- Operators/owners of DHC-8 aeroplanes of Models 102, 103, 106, 201, 202, 301, 311, 314 and 315 with serial numbers 3 through 433 (Applicability).\n\nWho pays and what they must do\n\n- The aircraft operators/owners must arrange for and pay for the installation of Modification 8/2376 in accordance with the cited service bulletin (Requirement). This is a physical modification to the aircraft's roll disconnect system.\n\nTiming and enforcement\n\n- The directive became effective on 21 May 1998 and requires compliance before 21 November 1998 (This airworthiness directive becomes effective on 21 May 1998; Compliance).\n\nWhy this was issued\n\n- The stated reason is that several incidents of uncommanded roll system disconnects during landing were reported (Background). The directive also notes a related Transport Canada airworthiness directive, AD CF-98-04 (Note).\n\nPractical implications, incentives and trade-offs (source-grounded)\n\n- Incentives/costs: Operators bear the cost of procuring and installing the modification and must schedule aircraft downtime to complete the work (Requirement; Compliance). The service bulletin (an external technical document) prescribes how the modification is to be carried out, so compliance depends on access to parts, technical instructions and maintenance capability (Requirement).\n\n- Behavioural effect: Affected operators must change maintenance plans to include this modification by the compliance date; failure to comply would leave aircraft outside this airworthiness directive and could expose them to regulatory action or operational restrictions (Applicability; Compliance).\n\n- Implementation risk and discretion: The directive mandates following the specified service bulletin. Any practical questions about execution (parts availability, maintenance scheduling) are resolved in the implementation process by operators and maintenance organisations under the service bulletin and regulatory oversight (Requirement; Note).\n\nSource citations: Applicability; Requirement; Note (Transport Canada AD); Compliance; This airworthiness directive becomes effective on 21 May 1998; Background."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific technical fault in specific aircraft. It has not expanded beyond its original purpose of mandating a single safety modification."},"complexity_factors":["Very short document (approximately 200 words)","Only 3 defined elements: specific aircraft models, serial number range, and the required modification reference","Single unconditional requirement with clear compliance deadline","No nested exceptions or conditional logic","No cross-references to other legislation sections — only a reference to a technical service bulletin and a related Canadian directive","Straightforward applicability test (model number + serial number check)"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific Bombardier DHC-8 aircraft (also known as Dash 8s) to install a safety modification to fix a problem with the **roll disconnect system** — a mechanism that can disconnect the aircraft's aileron controls (the surfaces that make the plane roll left or right).\n\n**Who it affects:**\n- **Aircraft affected:** DHC-8 models 102, 103, 106, 201, 202, 301, 311, 314, and 315 with serial numbers 3 through 433\n- **People affected:** Airlines, charter operators, and private owners flying these specific aircraft in Australia\n\n**Why it matters:** Several incidents were reported where the roll system disconnected unexpectedly during landing — a dangerous situation that could affect the pilot's ability to control the aircraft. This directive mandates a specific factory modification (Modification 8/2376, detailed in de Havilland Service Bulletin 8-27-79 Rev A) to prevent this from happening.\n\n**Key deadlines:**\n- **Effective date:** 21 May 1998 (when the rule became active)\n- **Compliance deadline:** Before 21 November 1998 (when the fix had to be completed)\n\n**International link:** This aligns with a Canadian safety order (Transport Canada AD CF-98-04), showing how aviation safety standards are coordinated across countries."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-53-roll-disconnect-system","history":"/api/acts/ad-dhc-8-53-roll-disconnect-system/history","analysis":"/api/acts/ad-dhc-8-53-roll-disconnect-system/analysis","conflicts":"/api/acts/ad-dhc-8-53-roll-disconnect-system/conflicts","importantCases":"/api/acts/ad-dhc-8-53-roll-disconnect-system/important-cases","documents":"/api/acts/ad-dhc-8-53-roll-disconnect-system/documents"}}