{"id":"F2006B08382","name":"AD/CESSNA 400/98 - Horizontal Stabiliser Fwd Attach Bulkhead","slug":"ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115812,"registerId":"commonwealth-F2006B08382-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/98 - Horizontal Stabiliser Fwd Attach Bulkhead","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)  \nCessna 400 Series Aeroplanes\n\nAD/CESSNA 400/98 Horizontal Stabiliser Fwd Attach Bulkhead 5/92\n\nApplicability: Model 441 serial numbers 441-001 through 441-0362 with time in service exceeding 3000 hrs.\n\nRequirement: 1. Inspect the horizontal stabiliser forward attach bulkhead for cracks and fretting in accordance with Cessna Service Bulletin CQB91-1 Revision 1.\n\n2. If Service Kit SK 441-103 has been installed, inspect and adjust the gap between the F.S.404.145 bulkhead and the horizontal stabiliser aft attach points in accordance with the Accomplishment Instructions of SK 441-103A.\n\nCompliance: 1. Unless already accomplished, inspect within 200 hours in service, at the next removal of the horizontal stabiliser, or before 30 April 1993, whichever occurs first, & then at intervals not exceeding 2000 hours until Service Kit SK 441-103 is installed.\n\n2. Unless already accomplished, inspect and adjust the gap within 200 hours in service, the next time there is access to the affected parts, or before 30 April 1993, which ever occurs first.\n\nBackground: Several instances of cracking in the horizontal stabiliser attach bulkhead have been reported.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains focused on inspecting and, where applicable, adjusting the horizontal stabiliser forward attach bulkhead for specified Cessna 441 serial numbers with >3,000 hours. The instrument prescribes inspection method references and specific compliance time windows but does not expand applicability beyond the stated serial-number/time-in-service cohort (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow technical scope limited to a single component on a defined serial-number range (Applicability)","Reliance on external technical documents for the inspection and adjustment procedures (Cessna Service Bulletin CQB91-1 Rev 1; SK 441-103A) increases operational detail required","Multiple compliance triggers and deadlines (within 200 hours, next removal, or a fixed calendar date) introduce scheduling complexity (Compliance)","Interaction with optional/installed Service Kit SK 441-103 affects inspection requirements and creates conditional compliance paths (Requirement)","Periodic re-inspection until kit installation imposes ongoing maintenance burden and record-keeping on operators (Compliance)","Technical skill and access to parts for gap adjustment may require certified maintenance organisations, raising direct cost to owners (Requirement)"],"plain_english_summary":"This airworthiness directive requires operators of Cessna 441 aeroplanes (serials 441-001 to 441-0362) with more than 3,000 hours to inspect the horizontal stabiliser forward attach bulkhead for cracks and fretting, and—if a specified service kit is fitted—to inspect and adjust the gap per the kit instructions. It sets firm short-term deadlines (within 200 flight hours or by 30 April 1993) and recurring inspection intervals until the kit is installed, so aircraft owners/operators must pay for inspections, any adjustments and follow mandated maintenance procedures. (Applicability; Requirement; Compliance)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific structural defect in a defined aircraft population. It has not expanded beyond its original purpose of mandating inspections for the horizontal stabiliser bulkhead cracking issue."},"complexity_factors":["Single, specific aircraft model and serial number range (441-001 through 441-0362)","Only 2 main requirements with clear conditional branches (whether Service Kit SK 441-103 is installed)","Straightforward compliance timeline with three alternative triggers (hours, maintenance event, or calendar date)","No defined terms section — uses standard aviation terminology","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Single background sentence explaining the safety rationale","Total length: approximately 200 words"],"plain_english_summary":"CASA requires owners/operators of certain Cessna 441 Conquest aeroplanes (s/n 441‑001 to 441‑0362) with over 3,000 hours to inspect the horizontal stabiliser forward attach bulkhead for cracking and fretting after reports of damage that could allow stabiliser separation. Inspections must follow Cessna’s service bulletin, include a gap check if a specific repair kit was fitted, be done within the stated short window, and repeat every 2,000 hours until a permanent repair is fitted."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead","history":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead/history","analysis":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead/analysis","conflicts":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead/conflicts","importantCases":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead/important-cases","documents":"/api/acts/ad-cessna-400-98-horizontal-stabiliser-fwd-attach-bulkhead/documents"}}