{"id":"F2006B09197","name":"AD/DHC-8/41 - Stall Warning System Computer","slug":"ad-dhc-8-41-stall-warning-system-computer","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53010,"registerId":"commonwealth-F2006B09197-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/41 - Stall Warning System Computer","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)  \nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/41 Stall Warning System Computer 7/95\n\nDM\n\nApplicability: Model DHC-8, series 102, 103 and 106, serial numbers 003 and subsequent with Safe Flight stall warning computers part number (P/N) 3605-4, -5 or -6 installed.\n\nRequirement: 1. Action in accordance with Bombardier Regional Aircraft Division de Havilland Dash 8 Alert Service Bulletin A8-27-73 dated 25 November 1993.\n\n2. Amend the DHC-8 Minimum Equipment List (MEL) in accordance with Temporary Revision No. 20 of the DHC-8 Master Minimum Equipment List (MMEL), ATA Chapter 27, ‘FLIGHT CONTROLS’, Item 27-2, ‘Stall Warning System’ for Series 100 pre-mod 8/2072 aircraft only, as follows:\n\nOne stall warning computer may be inoperative for three flight days (Category A), provided the inoperative system is deactivated and the remaining operative system is confirmed operative in the ‘AIRBORNE MODE’ each flight day.\n\nNote: Transport Canada Aviation AD CF-95-06 dated 10 April 1995 refers.\n\nCompliance: 1. Within 50 hours time in service after 18 May 1995, unless already accomplished within the last 400 hours time in service. Thereafter at intervals not to exceed 450 hours time in service.\n\n2. At initial inspection in accordance with this Directive.\n\nIncorporation of de Havilland Modification 8/2072 terminates the requirement for the repetitive test and the amendment to the MEL.\n\nBackground: A routine “C” check discovered that the stick shakers did not activate when tested. Investigations have determined that relay contacts within the stall warning computer had become contaminated and no longer provided a sufficient path to ground for shaker operation.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD retains a focused scope limited to specified DHC‑8 airframes with particular stall warning computer part numbers and prescribes targeted inspections plus a temporary MEL change; incorporation of Mod 8/2072 removes the AD requirements. There is no expansion beyond addressing the contaminated relay contact failure identified in the Background."},"complexity_factors":["Narrow technical applicability: applies only to DHC‑8 Series 102/103/106 serials 003+ with specific Safe Flight P/Ns (Applicability).","Two coordinated compliance tracks: repetitive testing per manufacturer Alert Service Bulletin and a temporary MEL amendment allowing limited dispatchability (Requirement 1 & 2).","Specific timing rules with exceptions: initial compliance within 50 flight hours after the AD date unless already done inside the last 400 hours; thereafter every 450 hours (Compliance).","Termination mechanism: incorporating De Havilland Modification 8/2072 cancels the repetitive test and MEL amendment, creating an upgrade option (Incorporation of modification).","Operational burden on operators: direct costs for repeated inspections, MEL administrative changes and possible scheduling or dispatch limits when a computer is inoperative (Requirement 2; Compliance).","Delegated technical action: tests are to be conducted in accordance with the Bombardier Alert Service Bulletin, so operators must follow an external document for procedures (Requirement 1).","Safety rationale tied to a specific failure mode: relay contact contamination prevented stick shaker activation — the AD prescribes testing and a stop‑gap MEL change to manage this risk (Background).","Cross‑reference to another authority: notes Transport Canada AD CF‑95‑06, which may affect international operator compliance tracking (Note)."],"plain_english_summary":"This Airworthiness Directive requires certain De Havilland DHC‑8 Series 100 aeroplanes (serials 003 onwards) fitted with Safe Flight stall warning computers P/N 3605‑4, ‑5 or ‑6 to undergo repetitive functional tests of the stall warning computer (per Bombardier Alert Service Bulletin) and a temporary MEL change allowing one computer inoperative under conditions. Tests repeat at set flight‑hour intervals; installing De Havilland Modification 8/2072 ends the testing and MEL amendment. Operators and maintainers bear the inspection, MEL amendment and modification costs."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard single-issue Airworthiness Directive addressing a specific safety defect in a specific aircraft system. The scope remains tightly focused on the stall warning computer issue as originally identified. The inclusion of MEL amendment procedures and the modification termination clause are standard regulatory mechanisms for such directives, not scope creep."},"complexity_factors":["Multiple applicability conditions: specific aircraft models (DHC-8-102/103/106), serial number range (003+), and specific part numbers (P/N 3605-4, -5, -6)","Two distinct compliance actions with different timing requirements (inspection/repetitive testing vs. one-time MEL amendment)","Conditional termination clause: requirement ends upon incorporation of specific modification (8/2072)","Cross-reference to external documents: Bombardier Alert Service Bulletin A8-27-73 and Transport Canada AD CF-95-06","Technical aviation terminology requiring domain knowledge (MEL, MMEL, ATA Chapter 27, Category A, 'time in service', 'airborne mode')","Nested applicability for MEL amendment: only applies to 'Series 100 pre-mod 8/2072 aircraft'"],"plain_english_summary":"Owners/operators of certain Bombardier DHC‑8 Series 100 aircraft must inspect and repair contaminated relay contacts in the stall‑warning computer after stick shaker failures were found. The AD requires following Bombardier Alert Service Bulletin A8‑27‑73, updating the MEL to allow operation with one failed computer for up to three days (Category A) with daily airborne‑mode checks, and repeating inspections until the permanent de Havilland modification is installed. This prevents loss of critical stall warnings."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-41-stall-warning-system-computer","history":"/api/acts/ad-dhc-8-41-stall-warning-system-computer/history","analysis":"/api/acts/ad-dhc-8-41-stall-warning-system-computer/analysis","conflicts":"/api/acts/ad-dhc-8-41-stall-warning-system-computer/conflicts","importantCases":"/api/acts/ad-dhc-8-41-stall-warning-system-computer/important-cases","documents":"/api/acts/ad-dhc-8-41-stall-warning-system-computer/documents"}}