{"id":"F2006L00722","name":"AD/CONVAIR/1 - Horizontal Stabiliser Attachment Fitting Lugs","slug":"ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136747,"registerId":"commonwealth-F2006L00722-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Kelowna Flightcraft (General Dynamics/Co","sectionType":"division","heading":"Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes","content":"### Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes\n\n| AD/CONVAIR/1 | Horizontal Stabiliser Attachment Fitting Lugs | 4/2006 |\n| ------------ | --------------------------------------------- | ------ |\n\n| Applicability: | All model 340, 440, and all such model aircraft converted to turbopropeller power. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Perform a visual inspection of the upper and lower, forward and aft, horizontal stabiliser attachment fitting lugs in accordance with the Accomplishment Instructions of General Dynamics, Convair Division, Service Bulletin640 (340D) 55-3A, Revision 1.2. Perform an ultrasonic inspection of the upper and lower, forward and aft, horizontal stabiliser attachment fitting lugs in accordance with the Accomplishment Instructions of Service Bulletin 640 (340D) 55-3A.If cracks are found during any above inspection, replace with a new part before further flight.3. Install bushings in the horizontal stabiliser attachment fitting lug holes in accordance with the Accomplishment Instructions of Service Bulletin640 (340D) 55-3A.4. Perform an internal visual inspection for cracks in the horizontal stabiliser attachment fittings, upper and lower, forward and aft, and associated structure outboard of the lugs and butt rib in the area surrounding the fasteners, in accordance with the Accomplishment Instructions of Service Bulletin640 (340D) 55-4 Revision 1. Inspect for evidence of loose rivets or fasteners in the stabiliser attachment fittings with particular attention given to those just outboard of the butt rib which fasten the upper forward fittings to the spar web and rail.If cracks are found in the stabiliser attachment fittings or associated structure, and/or if loose fasteners are detected in the stabiliser attachment fitting: replace the fitting with a new part, repair structure, and/or replace the fasteners in accordance the Accomplishment Instructions of Service Bulletin640 (340D) 55-4, before further flight. |\n\n| | 5. Perform an x-ray inspection for cracks in the upper forward and upper aft horizontal stabiliser attachment fittings in the area outboard of the lugs in accordance with the Accomplishment Instructions of Service Bulletin640 (340D) 55-4. Only the four upper fittings are required to be x-ray inspected as they are the most highly loaded in tension and therefore most susceptible to fatigue cracking. If cracks are found, replace with a new part before further flight.6. Replace the first three steel rivets outboard of the butt rib through the two forward upper horizontal stabiliser attachment fittings in accordance with the Accomplishment Instructions of Service Bulletin 640 (340D) 55-4.Note: FAA AD 82-19-02 Amdt 39-4458 refers. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | 1. Within 250 hours time in service after 13 April 2006, unless previously accomplished within 450 hours before 13 April 2006; thereafter at intervals not to exceed 700 hours time in service.2. Within 250 hours time in service after 13 April 2006, unless previously accomplished within 1150 hours time in service before 13 April 2006; thereafter at intervals not to exceed 1400 hours time in service.3. Unless already accomplished, within 10,000 hours time in service after 16 September 1982 (the effective date of FAA AD 82-19-02). Continue to inspect after bushing replacement in accordance with Requirement 1 and 2.4. Within 250 hours time in service after 13 April 2006, unless previously accomplished within 450 hours time in service before 13 April 2006; thereafter at intervals not to exceed 700 hours time in service.5. Within 250 hours time in service after 13 April 2006, unless previously accomplished within 1150 hours time in service before 13 April 2006; thereafter at intervals not to exceed 1400 hours time in service.6. Unless already accomplished, within 10,000 hours time in service after 16 September 1982 (the effective date of FAA AD 82-19-02). Continue to inspect after rivet replacement in accordance with Requirement 4 and 5. |\n| | This Airworthiness Directive becomes effective on 13 April 2006. |\n\n| Background: | The FAA requires certain inspections to prevent the possible loss of the horizontal stabiliser due to failure of the stabiliser attachment fittings (part numbers340-8510150 and 340-8510151), caused by fatigue cracks. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n1 March 2006","sortOrder":0},{"sectionNumber":"AD/CONVAIR/1","sectionType":"part","heading":"AD/CONVAIR/1","content":"## AD/CONVAIR/1","sortOrder":1},{"sectionNumber":"Horizontal Stabiliser Attachment Fitting","sectionType":"part","heading":"Horizontal Stabiliser Attachment Fitting Lugs","content":"## Horizontal Stabiliser Attachment Fitting Lugs","sortOrder":2},{"sectionNumber":"4/2006","sectionType":"part","heading":"4/2006","content":"## 4/2006","sortOrder":3}],"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":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope as a safety-critical airworthiness directive targeting specific fatigue-prone components on Convair 340/440 aircraft. It has not expanded beyond its original purpose of preventing horizontal stabiliser attachment failures."},"complexity_factors":["Multiple inspection methods required (visual, ultrasonic, X-ray, internal visual) with different technical standards","Six distinct compliance requirements with different deadlines and recurring intervals (250 hours, 450 hours, 700 hours, 1,150 hours, 1,400 hours, 10,000 hours)","Cross-references to external technical documents (General Dynamics Service Bulletins 640 (340D) 55-3A and 55-4) that are not reproduced in the directive","Conditional logic: 'unless previously accomplished' clauses create alternative compliance paths based on prior maintenance history","Specific part numbers referenced (340-8510150, 340-8510151) requiring technical lookup","Nested conditions: some requirements trigger ongoing obligations (e.g., 'Continue to inspect after bushing replacement in accordance with Requirement 1 and 2')","Reference to foreign regulatory instrument (FAA AD 82-19-02) for background context"],"plain_english_summary":"This AD mandates inspections and corrective work on older Convair 340/440 (including turboprop conversions) to stop metal-fatigue cracks in the horizontal-stabiliser attachment fittings that could cause the tail to detach in flight. Owners/operators and qualified maintenance personnel must carry out repetitive inspections, detect hidden cracks, fit protective bushings, and replace vulnerable rivets.\n\nIt matters because these ageing airframes face a long‑recognised risk of catastrophic structural failure; the AD enforces recurring checks to catch and fix problems before they become dangerous."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The AD maintains the safety scope evident in the referenced FAA AD (preventing stabiliser loss from fatigue cracking) and applies to all Convair 340/440 models and turboprop conversions. It consolidates inspection and corrective steps (visual/ultrasonic/X‑ray, bushing installation, rivet replacement) but does not expand applicability beyond the listed models in the source text."},"complexity_factors":["Multiple inspection methods required (visual, ultrasonic, X‑ray) with different scopes for upper/lower and forward/aft fittings.","Staged compliance intervals tied to hours‑in‑service and historic accomplishment windows, creating scheduling complexity.","Mandatory corrective actions before further flight if cracks are found, requiring spare parts and potential structural repair capability.","Installation of bushings and replacement of specific rivets adds modification work beyond inspection.","Dependence on manufacturer service bulletins (General Dynamics, Convair Service Bulletin 640 (340D) 55‑3A / 55‑4) for accomplishment instructions increases procedural specificity.","Reference to an earlier FAA AD and asymmetric inspection requirements (only four upper fittings X‑rayed) creates differential treatment within the same component group.","Need for specialised non‑destructive testing equipment and certified technicians (ultrasonic, X‑ray) increases compliance cost and logistic burden."],"plain_english_summary":"This Airworthiness Directive requires operators of Convair model 340 and 440 aeroplanes (including turboprop conversions) to inspect the horizontal stabiliser attachment lugs and fittings, install bushings, and replace specified rivets. Inspections include visual, ultrasonic and X‑ray checks; any cracked parts must be replaced before further flight. The stated purpose is to prevent loss of the stabiliser from fatigue cracking. Operators bear the inspection, testing, repair and downtime costs under the stated time‑in‑service intervals and service bulletin procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs","history":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs/history","analysis":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs/analysis","conflicts":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs/conflicts","importantCases":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs/important-cases","documents":"/api/acts/ad-convair-1-horizontal-stabiliser-attachment-fitting-lugs/documents"}}