{"id":"F2006B03375","name":"AD/B767/2 - Ram Air Turbine, Rotary Actuator - Replacement and Test","slug":"ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42838,"registerId":"commonwealth-F2006B03375-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B767/2 - Ram Air Turbine, Rotary Actuator - Replacement and Test","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 767 Series Aeroplanes\n\n \n\n# AD/B767/2  Ram Air Turbine, Rotary Actuator - Replacement and Test\n\nApplicability: All models equipped with ram air turbine rotary actuator P/No. S258T711-3.\n\n# 3/85\n\n \n\nRequirement: 1. Replace ram air turbine rotary actuator P/No. S258T711-3 with rotary actuator P/No. S258T711-4.\n\n \n\n2. Test ram air turbine deployment system in accordance with Boeing Service Bulletin 767-29-17, Revision 2, dated 29 June 1984 or later approved revision.\n\n \n\nNote: FAA AD 84-25-03 Amdt 39-4969 refers.\n\n \n\nCompliance: Before 31 July 1985.\n\n \n\nBackground:  Moisture accumulation on the rotary actuator brake assembly can, under freezing conditions, cause the brake rotor to freeze to the brake armature, thus rendering the ram air turbine deployment system inoperative.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft system. It has not expanded beyond its original purpose of mandating a part replacement to prevent freezing failures in the ram air turbine deployment system."},"complexity_factors":["Single, specific mechanical part replacement with clear part numbers","One straightforward testing requirement referencing an external Boeing document","No defined terms section","No conditional logic or nested exceptions","Simple applicability test (specific part number presence)","Single compliance deadline with no exceptions or alternative methods"],"plain_english_summary":"Owners/operators of certain Boeing 767s must replace a ram air turbine rotary actuator (P/N S258T711-3) with an improved unit (P/N S258T711-4) and test the emergency deployment system per Boeing service instructions. \n\nThis affects Boeing 767s fitted with the faulty part; it prevents cold-weather freezing of the emergency backup power deployment. Compliance was required by 31 July 1985."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This directive changes installed equipment and mandated practice: it requires replacing rotary actuator P/No. S258T711-3 with P/No. S258T711-4 and performing a deployment-system test (Requirement 1 & 2). The Civil Aviation Safety Authority (header) imposes the obligation on operators of affected Boeing 767s (Applicability), who therefore bear the costs and scheduling burden of parts replacement and testing before the stated compliance date (Compliance). The change is directly targeted at the moisture/freezing failure described (Background)."},"complexity_factors":["Narrow technical applicability: only aircraft fitted with P/No. S258T711-3 are affected (Applicability).","Two discrete mandatory actions: part replacement and system test (Requirement 1 & 2).","Normative external reference: testing must follow Boeing Service Bulletin 767-29-17 or later approved revision (Requirement 2).","Fixed compliance deadline requires operators to schedule maintenance within a set timeframe (Compliance).","Safety-critical operational consequence tied to environmental conditions (moisture freezing the brake) (Background).","Practical dependencies: part availability, workshop capacity and potential aircraft downtime (implied by Replacement/Test requirements).","Cross-reference to FAA AD indicates alignment with foreign regulator action (Note)."],"plain_english_summary":"**Requires Boeing 767 aeroplanes fitted with ram air turbine rotary actuator P/No. S258T711-3 to replace it with P/No. S258T711-4 and to test the ram air turbine deployment system in accordance with Boeing Service Bulletin 767-29-17 (or later approved revision).** Compliance was set before 31 July 1985. The directive targets a moisture/freezing failure mode that can immobilise the actuator brake; it creates a direct replacement-and-test obligation for affected operators, with associated parts, labour and scheduling costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test","history":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test/history","analysis":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test/analysis","conflicts":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test/conflicts","importantCases":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test/important-cases","documents":"/api/acts/ad-b767-2-ram-air-turbine-rotary-actuator-replacement-and-test/documents"}}