{"id":"F2006B10057","name":"AD/G159/13 Amdt 3 - Trim Tab Actuators","slug":"ad-g159-13-amdt-3-trim-tab-actuators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55502,"registerId":"commonwealth-F2006B10057-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/G159/13 Amdt 3 - Trim Tab Actuators","content":"COMMONWEALTH OF AUSTRALIA CIVIL AVIATION ORDERS CIVIL AVIATION SAFETY AUTHORITY PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nGULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES\n\nAD/G159/13 Amdt 3 Trim Tab Actuators 10/9 7\n\nApplicability: All models not fitted with trim tab actuators Part Number 159SCC100-11.\n\nRequirement: 1. Action in accordance with Gulfstream (Grumman) Customer Bulletin 208A as amended by Amendments 1 and 2.\n\n2. Install trim tab actuator 159SCC100-11 in accordance with Gulfstream Aircraft Service Change 191.\n\nNote: FAA AD 97-14-09 refers\n\nCompliance: 1. Within 200 hours time in service after the last inspection carried out in accordance with the previous issue of this Directive, or before 30 September 1997, whichever occurs last; thereafter at intervals not exceeding 200 hours time in service.\n\n2. Within 1000 hours time in service after 11 September 1997.\n\nThis airworthiness directive becomes effective on 11 September 1997.\n\nBackground: This directive was originally issued with subsequent amendment to prevent failure of the of the elevator trim tab mounting lugs due to cracking.\n\nAmendment 3 is issued to provide terminating action for the inspection.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. The original directive required recurring inspections to prevent cracking of elevator trim‑tab mounting lugs. Amendment 3 adds a terminating action: it requires installation of actuator 159SCC100-11 per Gulfstream Service Change 191, which, once installed, ends the recurring inspection requirement."},"complexity_factors":["Cross-references to external manufacturer documents (Gulfstream Customer Bulletin 208A as amended and Gulfstream Aircraft Service Change 191) creating dependency on those texts for implementation.","Multiple, conditional compliance time triggers (inspection: within 200 hours after last inspection or before 30 Sep 1997, then every ≤200 hours; installation: within 1,000 hours after 11 Sep 1997).","Applicability tied to a specific part number (applies only to aircraft not fitted with part 159SCC100-11), requiring accurate fleet configuration checks.","Amendment introduces a terminating action (installation ends recurring inspections), changing ongoing maintenance planning and recordkeeping.","Reference to FAA AD 97-14-09 implies alignment with foreign authority and potential additional compliance implications.","Operational impact: scheduling installation within the specified hours may require out-of-service time and coordination with maintenance providers."],"plain_english_summary":"Mandates inspections and the installation of trim-tab actuator part 159SCC100-11 on Gulfstream G.159-series aeroplanes not already fitted with that part.\n\nAircraft operators must perform recurring 200‑hour inspections until they install the specified actuator (installation required within 1,000 hours of 11 Sep 1997). CASA enforces compliance; operators bear the cost. The directive says this action is intended to prevent cracking and failure of elevator trim‑tab mounting lugs, and Amendment 3 makes the installation a terminating action for the inspection requirement."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 3 to an existing Airworthiness Directive. The amendment adds a terminating action (the replacement requirement) to end the recurring inspection mandate, but does not expand the scope beyond the original safety issue (cracked trim tab mounting lugs on G.159 aircraft). The scope remains tightly focused on the specific mechanical defect identified in the original directive."},"complexity_factors":["Single aircraft type applicability (Gulfstream G.159 series only)","Two distinct compliance paths with clear time-based triggers (200 hours/1000 hours)","Only one defined part number referenced (159SCC100-11)","No nested exceptions or conditional logic — straightforward 'if not fitted, then comply'","References external technical documents (Customer Bulletin 208A, Service Change 191, FAA AD 97-14-09) but does not incorporate their text","Total length: approximately 150 words"],"plain_english_summary":"A safety order for Gulfstream G.159 aircraft requires owners, operators and maintenance organisations to inspect and replace faulty elevator trim tab actuators. Affected aircraft without the improved actuator must undergo repeated inspections for cracked mounting lugs and then have the upgraded actuator fitted as the permanent fix.  \n\nThis prevents trim tab failure—which could lead to loss of control—by mandating interim checks and a hardware upgrade."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators","history":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators/history","analysis":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators/analysis","conflicts":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators/conflicts","importantCases":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators/important-cases","documents":"/api/acts/ad-g159-13-amdt-3-trim-tab-actuators/documents"}}