{"id":"F2006L00137","name":"AD/DHC-8/106 - Control Column Torque Tube Rivets","slug":"ad-dhc-8-106-control-column-torque-tube-rivets","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58017,"registerId":"commonwealth-F2006L00137-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-8/106 | Control Column Torque Tube Rivets | 2/2006 |\n| ------------ | --------------------------------- | ------ |\n\n| Applicability: | Model DHC-8-102, -103, -106, -201, -202, -301, -311, -314, and -315 aircraft, serial numbers 528 through 602, and 606.Model DHC-8-400, -401, and -402 aircraft, serial numbers 4003, 4004, 4006, 4008 through 4080, and 4082. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For Model DHC-8-102, -103, -106, -201, -202, -301, -311, -314, and -315 aircraft, serial numbers 528 through 602, and 606:Carry out an inspection of the left and right control column torque tube assemblies to determine the rivet types installed, in accordance with Part A of the Accomplishment Instructions of Bombardier Service Bulletin (SB) 8-27-104, dated 26 October 2004, or later Transport Canada approved revision.If any rivet is found to be of an incorrect type or the type cannot be identified, before further flight, rework the control column torque tube in accordance with Part B of the Accomplishment Instructions of SB 8-27-104, dated 26 October 2004, or later Transport Canada approved revision.2. For Model DHC-8-400, -401, and -402 aircraft, serial numbers 4003, 4004, 4006, 4008 through 4080, and 4082:Carry out an inspection of the left and right control column torque tube assemblies to determine the rivet types installed, in accordance with Part A of the Accomplishment Instructions of Bombardier Service Bulletin (SB) 84-27-24 Revision A, dated 28 September 2005, or later Transport Canada approved revision.If any rivet is found to be of an incorrect type or the type cannot be identified, before further flight, rework the control column torque tube in accordance with Part B of the Accomplishment Instructions of SB 84-27-24 Revision A, dated 28 September 2005, or later Transport Canada approved revision.Note: Transport Canada AD CF-2005-39 refers. |\n| Compliance: | Within 5,500 flight hours after 16 February 2006. |\n| | This Airworthiness Directive becomes effective on 16 February 2006. |\n\n| Background: | Several aircraft were found to have incorrect rivets of lower than required strength installed on the control column torque tube during production. This condition, if not corrected, could result in shear failure of control column torque tube rivets during a jam of the pitch control circuit. Failure of the rivets could reduce the controllability of the aircraft due to unexpected decoupling of the elevators and large unwanted deflection of the free elevator. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n6 January 2006","sortOrder":0},{"sectionNumber":"AD/DHC-8/106","sectionType":"part","heading":"AD/DHC-8/106","content":"## AD/DHC-8/106","sortOrder":1},{"sectionNumber":"Control Column Torque Tube Rivets","sectionType":"part","heading":"Control Column Torque Tube Rivets","content":"## Control Column Torque Tube Rivets","sortOrder":2},{"sectionNumber":"2/2006","sectionType":"part","heading":"2/2006","content":"## 2/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive addresses the specific production defect described (incorrect lower‑strength rivets) for identified models and serial numbers and requires remedial inspection and rework. It does not broaden or narrow obligations beyond correcting that defect as framed in the document."},"complexity_factors":["Model- and serial-number specific applicability — multiple DHC‑8 series and discrete serial ranges increase tracking and applicability checks.","Dependence on external documents — inspections and rework must follow Bombardier Service Bulletins (or later Transport Canada‑approved revisions), creating reliance on manufacturer/Regulator updates.","Two-tiered compliance requirement — routine inspection within 5,500 flight hours, with mandatory immediate rework (\"before further flight\") if incorrect or unidentifiable rivets are found, raising potential operational disruption.","Safety‑critical hardware access — torque tube rivets require hands-on inspection and possible structural rework, implying skilled labour, parts, and downtime.","Reference to another regulator AD (Transport Canada AD CF‑2005‑39) — cross-jurisdictional coordination may be needed for compliance interpretation."],"plain_english_summary":"Mandates inspection and, where necessary, rework of the left and right control column torque tube rivets on specified Bombardier (De Havilland) DHC‑8 models and serial numbers, using the referenced Bombardier Service Bulletins or later Transport Canada–approved revisions. Compliance is required within 5,500 flight hours from 16 February 2006.\n\nThe action responds to discovery of lower‑strength rivets in production; the stated safety purpose is to prevent rivet shear during a pitch‑control jam that could decouple the elevators and reduce aircraft controllability."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in control column rivets on specific DHC-8 aircraft. It has not expanded beyond this original safety purpose."},"complexity_factors":["Two distinct applicability groups with different technical reference documents (SB 8-27-104 vs SB 84-27-24 Revision A)","Specific serial number ranges that must be cross-checked rather than simple model-wide applicability","Conditional compliance logic: inspection required, but rework only triggered if specific fault conditions are met","External document incorporation by reference (Transport Canada approved service bulletins) — operators must obtain and follow separate technical manuals not reproduced in the AD itself","Time-based compliance mechanism (5,500 flight hours) rather than calendar date, requiring flight log tracking"],"plain_english_summary":"This AD mandates inspections of the left and right control column torque tubes on specific Bombardier DHC‑8 (Dash 8) serials to identify potentially incorrect, under‑strength rivets. If wrong or unidentifiable rivets are found, repairs are required before further flight, following Bombardier instructions, to be completed within 5,500 flight hours after 16 Feb 2006. \n\nIt matters because rivet failure could jam pitch controls and lead to loss of elevator control, creating a serious safety hazard."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets","history":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets/history","analysis":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets/analysis","conflicts":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets/conflicts","importantCases":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets/important-cases","documents":"/api/acts/ad-dhc-8-106-control-column-torque-tube-rivets/documents"}}