{"id":"F2006B09181","name":"AD/DHC-8/26 Amdt 1 - Horizontal Stabiliser Attachment Bolts","slug":"ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52947,"registerId":"commonwealth-F2006B09181-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/26 Amdt 1 - Horizontal Stabiliser Attachment Bolts","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-8/26\n\nAmdt 1\n\n  \nHorizontal Stabiliser Attachment Bolts 9/98\n\nApplicability: DHC-8 Series 100 aircraft, models 102, 103, and 106, with serial numbers 003\n\nthrough 349 excluding 316 and 345.\n\nDHC-8 Series 300 aircraft, models 301, 311, and 314, with serial numbers 100\n\nthrough 342 excluding 320, 338, and 340.\n\nRequirement: Inspect the horizontal stabiliser attachment bolts at all six locations in accordance with the following instructions:\n\n    Carry out a detailed visual inspection of the bolts in the area of the head radius for indications of cracks or laps using a 10x magnifying glass.\n\n    2. Carry out a magnetic particle inspection of the bolts.\n\nNote: Transport Canada AD CF-93-05R1 refers.\n\nCompliance: For the mid spar attachment bolts: within 25 hours time in service after 22 January 1993.\n\nFor the front and rear spar attachment bolts: within 50 hours time in service after 22 January 1993.\n\nThe compliance of the original issue of this directive remains unchanged. This amendment becomes effective on 13 August 1998.\n\nBackground: Several local reports were received of stabiliser mid spar attachment bolts with crack indications. Laboratory analysis revealed the cracks to be lap defects that were formed during manufacture. Small fatigue cracks from the laps were noted. The initial report findings were the result of compliance with SB 8-55-16, although the bolts did not have “PBF” marking on the head as specified in the service bulletin. As a precaution, the inspection was expanded to include the front and rear spar bolts.\n\nAmendment 1 is issued to align the applicability of this directive with the applicability of the subsequently issued Transport Canada AD, which is specific to aircraft that were in service at the time of the original issue of this directive.\n\nThe original issue of this airworthiness directive became effective on 22 January 1993.","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope. Amendment 1 simply narrows the applicability to match the Canadian directive, ensuring only aircraft actually in service at the time of the original 1993 directive are covered. This is a technical alignment rather than an expansion of scope."},"complexity_factors":["Very short document (approximately 300 words)","Only 3 defined applicability criteria (aircraft series, models, and serial numbers)","Simple two-step inspection requirement with no conditional logic or exceptions","Single cross-reference to a Canadian aviation directive (Transport Canada AD CF-93-05R1)","Clear, unambiguous compliance deadlines with no nested conditions","No subordinate legislation or regulations referenced beyond the enabling Civil Aviation Regulations 1998"],"plain_english_summary":"This Airworthiness Directive orders operators of specified Bombardier DHC‑8 (Dash 8) Series 100 and 300 aircraft to carry out mandatory inspections of the bolts securing the horizontal tail using close visual and magnetic particle techniques.  \n\nIt targets certain serial-numbered planes (some excluded) because cracked bolts were found that could lead to tail separation — a critical safety risk that grounded aircraft until inspections are completed."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 1 changes the scope by aligning the AD's applicability with the subsequently issued Transport Canada AD, making the directive specific to aircraft that were in service at the time of the original issue. The amendment therefore narrows which serial-numbered aircraft must comply (Amendment 1; Applicability)."},"complexity_factors":["Serial-number‑specific applicability requires operators to check fleet records to determine whether each airframe is affected (Applicability).","Two inspection techniques mandated: a detailed visual inspection with a 10× magnifier and a magnetic particle inspection (MPI) — MPI requires specialist equipment or contracted shop work (Requirement).","Short compliance windows (25 hours for mid spar, 50 hours for front/rear spar after 22 Jan 1993) create timing pressure and potential operational disruption (Compliance).","Amendment aligns applicability with a Transport Canada AD and restricts the directive to aircraft that were in service at the time of the original issue, changing which aircraft must comply (Amendment 1).","Background links the problem to manufacturing 'lap' defects that can initiate fatigue cracks, implying some inspections may lead to repairs or part replacement (Background).","Several excluded serial numbers and references to an earlier service bulletin add administrative steps and cross-referencing to prior compliance actions (Applicability; Background).","The directive preserves the original compliance requirements while changing applicability, producing overlapping effective dates and retrospective compliance considerations (Compliance; Amendment 1)."],"plain_english_summary":"This airworthiness directive requires operators of specified Bombardier (De Havilland) DHC‑8 Series 100 and 300 aircraft (listed by model and serial number) to inspect horizontal stabiliser attachment bolts at six locations for manufacturing defects. Inspections consist of a detailed visual check with a 10× magnifier and a magnetic particle inspection. (Requirement, Applicability)\n\nOperators must meet short compliance deadlines — 25 flight hours for mid‑spar bolts and 50 hours for front/rear spar bolts after 22 January 1993 — and bear the cost and scheduling of inspections and any follow‑on repairs. (Compliance, Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts","history":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts/history","analysis":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts/analysis","conflicts":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts/conflicts","importantCases":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts/important-cases","documents":"/api/acts/ad-dhc-8-26-amdt-1-horizontal-stabiliser-attachment-bolts/documents"}}