{"id":"F2007L02122","name":"AD/DHC-8/131 - Spring Tab Mechanism Bolts","slug":"ad-dhc-8-131-spring-tab-mechanism-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67255,"registerId":"commonwealth-F2007L02122-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bombardier (Boeing Canada/De Havilland) ","sectionType":"division","heading":"Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes","content":"### Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\n| AD/DHC-8/131 | Spring Tab Mechanism Bolts | 8/2007 |\n| ------------ | -------------------------- | ------ |\n\n| Applicability: | Bombardier Inc. Models DHC-8-102, DHC-8-103, DHC-8-106, DHC-8-201,DHC-8-202, DHC-8-301, DHC-8-311, DHC-8-314 and DHC-8-315, Serial Numbers 003 through 611.                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out a one-time inspection of the LH and RH elevator spring tab mechanism clamp bolts for correct installation, according to the Accomplishment Instructions of initial issue of Bombardier Service Bulletin (SB) 8-27-106, dated 7 Feb 2006, or later NAA approved revisions.2. If the inspection discovered any bolt that is incorrectly installed, re-install bolt according to the Accomplishment Instructions of the above-noted SB.Note: Transport Canada AD CF-2007-08 dated 4 June 2007 refers. |\n| Compliance:    | 1. Within 12 months after the effective date of this AD unless already accomplished.2. Prior to further flight after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                             |\n|                | This Airworthiness Directive becomes effective on 2 August 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | It has been discovered in several cases that clamp bolts of the elevator spring tab mechanism were not installed in the correct orientation. Bolts have been found installed with bolt heads on the lower position and in two cases, some bolts, nuts and washers were found to be loose or missing. Detachment of an elevator spring tab mechanism clamp bolt could lead to jamming of the elevator control system and reduced controllability of the aircraft.                                                |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n21 June 2007","sortOrder":0},{"sectionNumber":"AD/DHC-8/131","sectionType":"part","heading":"AD/DHC-8/131","content":"## AD/DHC-8/131","sortOrder":1},{"sectionNumber":"Spring Tab Mechanism Bolts","sectionType":"part","heading":"Spring Tab Mechanism Bolts","content":"## Spring Tab Mechanism Bolts","sortOrder":2},{"sectionNumber":"8/2007","sectionType":"part","heading":"8/2007","content":"## 8/2007","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to Bombardier DHC-8 models and serial numbers 003–611 and mandates a one-time inspection and re-installation per the referenced Service Bulletin. The text shows no expansion or narrowing of that original applicability or requirements."},"complexity_factors":["Narrow applicability to specific DHC-8 models and serial numbers (Applicability) reduces scope complexity.","Single mandatory action: one-time inspection with corrective re-installation if needed (Requirement) keeps operational steps simple.","Dependency on manufacturer Service Bulletin for technical instructions introduces an external reference to interpret and follow.","Fixed compliance windows (within 12 months; or prior to further flight if an incorrect bolt is found) create scheduling and operational constraints (Compliance).","Safety-critical consequence (potential elevator jamming) requires immediate corrective action if defects are discovered (Background), increasing urgency and possible aircraft downtime.","Assessment of 'correct installation' may require technical judgment or qualified maintenance personnel, creating modest compliance burden."],"plain_english_summary":"An Airworthiness Directive requires operators of specified Bombardier DHC-8 aeroplanes (serials 003–611) to carry out a one-time inspection of the left and right elevator spring-tab clamp bolts and to re-install any bolts that are fitted incorrectly, following the Bombardier Service Bulletin. The stated purpose is to prevent bolt detachment that could jam the elevator control system; operators pay for inspections and repairs and must comply within the time limits set in the AD (Requirement; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in a defined fleet of aircraft. It has not expanded beyond the original safety issue of incorrectly installed elevator spring tab mechanism bolts."},"complexity_factors":["Single, specific mechanical issue (bolt orientation on one aircraft system)","Only 2 compliance requirements (inspection and conditional repair)","Clear applicability table limiting to specific aircraft models and serial numbers","References only one external technical document (Service Bulletin 8-27-106)","No nested exceptions, conditional logic, or extensive defined terms","Short background section explaining the safety risk in plain language","Straightforward timeline: 12 months for inspection, immediate repair if fault found"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators of certain Bombardier DHC-8 series (serials 003–611) to inspect the elevator spring‑tab clamp bolts because some were found loose, incorrectly installed, or missing. A detached bolt could jam the elevator and jeopardize control. Inspections are required within 12 months (or sooner if due), defects must be corrected before flight, and work must follow Bombardier Service Bulletin 8‑27‑106. Effective 2 August 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts","history":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts/history","analysis":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts/analysis","conflicts":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts/conflicts","importantCases":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts/important-cases","documents":"/api/acts/ad-dhc-8-131-spring-tab-mechanism-bolts/documents"}}