{"id":"F2006L00694","name":"AD/SD3-60/69 Amdt 1 - Rudder Horn Spar","slug":"ad-sd3-60-69-amdt-1-rudder-horn-spar","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136710,"registerId":"commonwealth-F2006L00694-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Short SD3-60 Series Aeroplanes","sectionType":"division","heading":"Short SD3-60 Series Aeroplanes","content":"### Short SD3-60 Series Aeroplanes\n\n| AD/SD3-60/69 Amdt 1 | Rudder Horn Spar | 4/2006 |\n| ------------------- | ---------------- | ------ |\n\n| Applicability: | All Model SD3-60 aircraft. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For aircraft not previously inspected in accordance with the original issue of this Directive, inspect the rudder in accordance with Part B of Shorts Alert Service Bulletin (ASB) SD360-55-A22 Revision 1, or later EASA approved revision.Any damage observed when performing the inspections required by this Directive must be assessed, monitored and repaired in accordance with the instructions provided in ASB SD360-55-A22 Revision 1, or later EASA approved revision.Aircraft previously inspected in accordance with the original issue of this Directive are considered to have satisfied the initial inspection requirement of Part B of ASB 360-55-A22 Revision 1, if;No corrosion was detected, or;Any detected corrosion was addressed in accordance with the Structural Repair Manual, or an approved repair.2. If the extent of the corrosion and any corrective actions cannot be established from the original inspection records, then accomplish Part B of ASBSD360-55-A22 Revision 1, or later EASA approved revision.3. Repeat inspections in accordance with section 1.D of ASB SD360-55-A22 Revision 1, or later EASA approved revision.Note: UK CAA AD G-2006-0001 refers. |\n| Compliance: | 1. Before further flight after 13 April 2006.2. Within 28 days after 13 April 2006.3. As specified in the Requirement document. |\n| | This Amendment becomes effective on 13 April 2006. |\n\n| Background: | There have been several in-service reports of cracking of the rudder horn spar. On one aircraft, the cracking had progressed to the point where the spar failed and the lower mass balance weight detached from the rudder horn spar, causing secondary structural damage to the rudder’s front spar, rib 14 and outer skin. Initial investigation indicates the failure is due to fatigue cracking of the rudder horn spar and rib cleats. Loss of a mass balance can have an adverse effect on aircraft flutter characteristics, and with sufficient penetration of rib 14 the potential exists for restriction or jamming of the rudder.Amendment 1 is issued in response to a new UK CAA AD, which was issued to address corrosion findings revealed as a result of the initial inspections and to incorporate repetitive inspection in accordance with the Recommended Maintenance Programme. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n1 March 2006","sortOrder":0},{"sectionNumber":"AD/SD3-60/69 Amdt 1","sectionType":"part","heading":"AD/SD3-60/69 Amdt 1","content":"## AD/SD3-60/69 Amdt 1","sortOrder":1},{"sectionNumber":"Rudder Horn Spar","sectionType":"part","heading":"Rudder Horn Spar","content":"## Rudder Horn Spar","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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the original directive to address corrosion discovered during initial inspections and to incorporate repetitive inspections aligned with the Recommended Maintenance Programme. It adds acceptance criteria for earlier inspections (no corrosion or repaired per the Structural Repair Manual) and requires fresh inspection where records are insufficient, increasing ongoing compliance and record‑keeping obligations (Background; Requirement)."},"complexity_factors":["Normative dependence on an external service bulletin and later EASA‑approved revisions (ASB SD360-55-A22 Rev 1) — requires access to and application of that document (Requirement).","Conditional acceptance of prior inspections: prior compliance may be treated as satisfying the initial requirement only if records show no corrosion or that corrosion was repaired per the Structural Repair Manual or an approved repair (Requirement).","Record‑dependence: if original inspection records do not establish extent of corrosion or corrective actions, a fresh Part B inspection is mandatory (Requirement).","Repetitive inspection schedule is set by the ASB (section 1.D) rather than fixed intervals in the directive, requiring ongoing reference to the ASB for compliance timing (Requirement; Compliance).","Short compliance windows (before further flight after 13 April 2006; within 28 days) create potential operational disruption and immediate maintenance workload (Compliance).","Safety‑critical technical scope (rudder horn spar, mass balance, rib 14) requires specialist inspection, assessment and structural repair capability; repairs must follow ASB repair instructions or approved repairs (Requirement; Background).","Cross‑jurisdictional reference (UK CAA AD) and alignment with EASA approvals add regulatory coordination and possible variation in later approved revisions (Background; Requirement)."],"plain_english_summary":"This directive requires operators of all Short SD3-60 aircraft to inspect the rudder horn spar using Shorts Alert Service Bulletin SD360-55-A22 Revision 1 (or a later EASA‑approved revision), to assess, monitor and repair any damage found, and to carry out the repeat inspections the bulletin specifies. It responds to in‑service reports of fatigue cracking and corrosion that allowed a mass‑balance weight to detach, creating flutter and jamming risks; compliance deadlines include inspection before further flight after 13 April 2006 or within 28 days and ongoing checks."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original directive appears to have been a one-time inspection for fatigue cracking. Amendment 1 significantly expanded the scope to include: (1) corrosion findings discovered during initial inspections, (2) mandatory repetitive/ongoing inspections rather than a single check, and (3) alignment with a new UK CAA AD and updated manufacturer service bulletin. The directive evolved from a reactive crack-inspection to a comprehensive ongoing airworthiness monitoring program."},"complexity_factors":["Multiple conditional pathways based on prior inspection history (aircraft previously inspected vs. not previously inspected)","Cross-references to external technical documents: Shorts Alert Service Bulletin SD360-55-A22 Revision 1, EASA approved revisions, UK CAA AD G-2006-0001, and Structural Repair Manual","Nested compliance deadlines (before further flight vs. 28 days vs. ongoing repetitive intervals)","Technical aviation terminology requiring specialised knowledge (rudder horn spar, mass balance, flutter characteristics, rib cleats)","Amendment structure creates layered requirements (original issue vs. Amendment 1 distinctions)"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of Short SD3‑60 (Short 360) aircraft to inspect and, if necessary, repair the rudder horn spar for cracking and corrosion, following manufacturer procedures. \n\nIt responds to an incident where a mass‑balance weight detached—risking flutter and rudder jamming—and was amended to require ongoing repetitive inspections after corrosion was found."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar","history":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar/history","analysis":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar/analysis","conflicts":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar/conflicts","importantCases":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar/important-cases","documents":"/api/acts/ad-sd3-60-69-amdt-1-rudder-horn-spar/documents"}}