{"id":"F2006B09825","name":"AD/F406/1 - Canted Rib Upper Cap","slug":"ad-f406-1-canted-rib-upper-cap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54782,"registerId":"commonwealth-F2006B09825-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F406/1 - Canted Rib Upper Cap","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)  \nReims Aviation F406 Series Aeroplanes\n\nAD/F406/1 Canted Rib Upper Cap 6/99 DM\n\nApplicability: Model F406 aircraft, serial numbers F406-0001 through F406-0083.\n\nRequirement: Inspect the canted ribs upper cap in the centre wing carry-through area for cracks in accordance with Reims / Cessna Service Bulletin CAB 98-16.\n\nNote 1: Reims Aviation Service Bulletin F406-38 is equivalent to CAB98-16. Note 2: DGAC AD 1999-087(A).\n\nCompliance: 1. Unless already accomplished, perform initial inspection before further flight after 12 May 1999.\n\n    2. A modification shall be installed dependent upon the result of the initial inspection, but not later than 600 hours of operation or 12 months after this directive is effective, whichever occurs first; unless already accomplished.\n\n    3. Repetitive inspections shall be accomplished at intervals not to exceed 200 hours time in service or 12 months after the initial inspection, or until modified as specified in the Requirement document.\n\nThis Airworthiness Directive becomes effective on 12 May 1999.\n\nBackground: Cracks have been found in the canted ribs upper cap in the centre wing carry-through area.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety-critical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection and repair of the canted rib upper cap."},"complexity_factors":["Single, specific mechanical component addressed (canted rib upper cap)","Clear, sequential compliance requirements with specific timeframes","Only 2 cross-references to external documents (Service Bulletin CAB 98-16 and equivalent F406-38)","Limited applicability (specific model, specific serial number range)","No nested conditional logic or exceptions — straightforward if/then structure (inspect → modify if needed → repeat until modified)","Document is approximately 200 words"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Reims Aviation F406 aircraft (S/N 0001–0083) to inspect the centre wing “canted rib upper cap” for cracks and to carry out a prescribed modification within set time limits, with repetitive inspections required until modification is installed. It responds to discovered cracking that could cause catastrophic wing carry‑through failure, so compliance is legally required to keep affected aircraft airworthy in Australia."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive stays within its original safety-focused scope: it targets identified cracks in the centre wing carry‑through area for a defined set of serial numbers and mandates inspection and, if indicated, modification. It does not expand applicability beyond the listed aircraft or add unrelated obligations."},"complexity_factors":["Narrow applicability: specific to Reims F406 serials F406-0001–F406-0083 (limits affected population).","Multiple, conditional compliance deadlines: initial inspection before further flight after effective date; modification within 600 flight hours or 12 months if required; repetitive inspections every 200 hours or 12 months until modified.","Reliance on external technical documents: inspection and modification must follow Service Bulletin CAB 98-16 (equivalent F406-38), requiring operators to obtain and apply that material.","Conditional trigger: requirement to modify is “dependent upon the result of the initial inspection,” creating a decision point for operators and maintenance providers.","Cross-reference to foreign AD (DGAC AD 1999-087(A)) may require alignment with overseas regulatory records and practices.","Operational impacts: scheduling, downtime and record-keeping burdens for operators to meet inspection intervals and modification deadlines."],"plain_english_summary":"This directive requires owners/operators of Reims F406 aeroplanes (serial numbers F406-0001 to F406-0083) to inspect the canted ribs upper cap in the centre‑wing carry‑through area for cracks, using Reims/Cessna Service Bulletin CAB 98‑16 (F406‑38 is equivalent). \n\nIf the inspection indicates it, a modification must be fitted within 600 flight hours or 12 months; until modification, repeat inspections are required every 200 hours or 12 months. The action responds to discovered cracking and places inspection, modification and related costs and scheduling on operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f406-1-canted-rib-upper-cap","history":"/api/acts/ad-f406-1-canted-rib-upper-cap/history","analysis":"/api/acts/ad-f406-1-canted-rib-upper-cap/analysis","conflicts":"/api/acts/ad-f406-1-canted-rib-upper-cap/conflicts","importantCases":"/api/acts/ad-f406-1-canted-rib-upper-cap/important-cases","documents":"/api/acts/ad-f406-1-canted-rib-upper-cap/documents"}}