{"id":"F2006B09214","name":"AD/DHC-8/58 - Ladder Plate at Wing Station 139","slug":"ad-dhc-8-58-ladder-plate-at-wing-station-139","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53059,"registerId":"commonwealth-F2006B09214-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/58 - Ladder Plate at Wing Station 139","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-8/58 Ladder Plate at Wing Station 139 13/98\n\nApplicability: All DHC-8 aircraft, Models 101, 102, 103, 106, 201, 202, 301, 311, 314, and 315.\n\nRequirement: In order to detect cracks in the ladder plates before they reach a critical size and reduce the strength of the wing, accomplish the following:\n\n    Inspect in accordance with the Maintenance Program Manual (MPM) Temporary Revisions specified in the following table:\n\n| Models             | Maintenance Program Manual | Temporary Revision No. |\n| ------------------ | -------------------------- | ---------------------- |\n| 101, 102, 103, 106 | PSM 1-8-7                  | AWL-59                 |\n| 201, 202           | PSM 1-82-7                 | AWL2-11                |\n| 301, 311, 314, 315 | PSM 1-83-7                 | AWL3-64                |\n\n    2. If cracks are found, before further flight, report to Bombardier Regional Aircraft Division, Downsview, Ontario for disposition.\n\nNote: Transport Canada AD CF-98-30 refers.\n\nCompliance: At the initial and repetitive flight cycles specified in the MPM Temporary Revisions.\n\nThis Airworthiness Directive becomes effective on 3 December 1998.\n\nBackground: A fatigue crack has been found in the ladder plate on the upper inboard side of the wing at wing station 139, stringer 6, on four aircraft. These cracks were found during the 40,000 flight cycle inspection when the wing access panels were removed.\n\nTemporary revisions have been made to the Maintenance Program Manuals in order to find these cracks before they reach a critical size.","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":3,"scope_assessment":{"changed":false,"description":"This is a standard, targeted Airworthiness Directive addressing a specific safety issue (fatigue cracks in ladder plates). It has not expanded beyond its original purpose of mandating inspections for this particular defect."},"complexity_factors":["Single, specific technical requirement (inspect one component)","Clear applicability table limiting scope to specific aircraft models","Straightforward compliance mechanism (follow existing manual revisions)","Minimal conditional logic (only one 'if-then' scenario: if cracks found, report before flight)","No nested definitions or extensive cross-referencing to other legislation","Short document (approximately 250 words)","Single external reference (Transport Canada AD) for context only, not for substantive requirements"],"plain_english_summary":"This AD orders mandatory inspections of the ladder plate at wing station 139 on Bombardier DHC‑8 (Dash 8) Series 100/200/300 aircraft, with required reporting to the manufacturer and grounding until relief if cracks are found.  \n\nIt affects operators and maintenance crews in Australia — prompted by discovered fatigue cracks that could weaken wing structure, the measure ensures early detection and prevents a serious safety hazard."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD is narrowly scoped to detect and manage fatigue cracks in the ladder plate at wing station 139 on the listed DHC‑8 models. It mandates inspections and OEM reporting only for that specific structural location and does not extend to other components, additional models, or broader maintenance changes beyond the referenced MPM Temporary Revisions."},"complexity_factors":["Multiple model applicability: the AD covers ten DHC‑8 model variants, requiring operators across the fleet to apply the measure (Applicability).","Cross-references external documents: compliance depends on following specific Maintenance Program Manual Temporary Revisions (three different PSM documents and revision numbers) rather than full text in the AD (Requirement; Compliance).","Recurring compliance schedule: inspections must be done at initial and repetitive flight‑cycle intervals specified in the MPM revisions, creating ongoing operational planning and recordkeeping obligations (Compliance).","Immediate grounding trigger and OEM reporting: discovery of cracks requires 'before further flight' action and reporting to Bombardier in Ontario for disposition, imposing an operational stop and international reporting requirement (Requirement).","Safety-critical inspection access: detection occurred when access panels were removed during a high‑cycle inspection, implying potential workscope and access needs for operators to implement the inspections (Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified DHC‑8 models to inspect the ladder plate at wing station 139 for fatigue cracks according to Temporary Revisions to their Maintenance Program Manuals. If cracks are found the aircraft must not fly until Bombardier provides a disposition. It affects aircraft owners/operators (who pay for inspections and any repairs) and delegates the timing of checks to the MPM temporary revisions (initial and repetitive flight‑cycle intervals)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139","history":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139/history","analysis":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139/analysis","conflicts":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139/conflicts","importantCases":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139/important-cases","documents":"/api/acts/ad-dhc-8-58-ladder-plate-at-wing-station-139/documents"}}