{"id":"F2006B08654","name":"AD/CON/78 - Roller Rockers","slug":"ad-con-78-roller-rockers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51727,"registerId":"commonwealth-F2006B08654-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CON/78 - Roller Rockers","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nTeledyne Continental Motors Piston Engines\n\nAD/CON/78 Roller Rockers 5/98\n\nApplicability: TCM O-470, IO-470, IO-520, TSIO-520 and IO-550 series engines incorporating “Performance Engineering” exhaust valve roller rockers fitted in accordance with FAA Supplemental Type Certificate (STC) SE8594SW.\n\nNote 1: Only engines which have had exhaust valve roller rockers fitted by an STC are affected by this directive. Such engines should have details of the STC certified in the engine log book. Engines fitted with the standard TCM valve rockers are not affected.\n\nRequirement: To prevent an exhaust valve roller rocker failure resulting in a loss of engine oil, engine power loss and possible engine failure, remove “Performance Engineering” exhaust valve roller rockers fitted in accordance with STC SE8594SW from service.\n\nNote 2: FAA Airworthiness Directive 98-01-08 refers.\n\nCompliance: Within 25 hours time in service effective from 23 April 1998.\n\nThis airworthiness directive becomes effective on 23 April 1998.\n\nBackground: This directive has been issued to require certain valve rockers to be removed from service. The requirement is in response to reports of failures of “Performance Engineering” roller rocker arms installed under STC SE8594SW. An investigation of the failed roller rocker arms disclosed evidence of manufacturing errors. Valve rocker arm failure will result in a loss of engine power and possible loss of engine oil. Continued operation could then result in engine failure.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific safety defect in specific aftermarket engine parts. The scope remains precisely limited to the identified safety issue without expansion into broader regulatory areas."},"complexity_factors":["Single, specific technical requirement (remove specific part)","Narrow applicability limited to specific engine models with specific aftermarket modification","Only 2 defined technical terms (STC, time in service) with explanatory notes","No nested exceptions or conditional logic","Clear compliance deadline (25 hours time in service)","Short document (approximately 200 words)","Single cross-reference to related FAA directive (informational only)"],"plain_english_summary":"This CASA Airworthiness Directive orders immediate removal of aftermarket \"Performance Engineering\" exhaust valve roller rockers installed under an STC on certain Teledyne Continental Motors piston engines (O-470, IO-470, IO-520, TSIO-520, IO-550 series). Reported manufacturing defects have caused failures leading to oil loss, power loss, or complete engine failure. Affected owners/operators must remove the specified roller rockers within 25 engine hours from 23 April 1998."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains focused on roller rockers fitted under STC SE8594SW; engines with standard TCM valve rockers are explicitly excluded. The instrument continues to require removal of those STC-fitted parts only (see Applicability and Note 1)."},"complexity_factors":["Narrow applicability: only TCM O-470, IO-470, IO-520, TSIO-520 and IO-550 series engines with roller rockers fitted under STC SE8594SW are affected — (Applicability).","Identification burden: owner/operators must verify the presence of the STC in the engine log book to confirm applicability — (Note 1).","Short compliance window: affected parts must be removed within 25 hours time in service from the effective date, imposing urgent scheduling and potential grounding — (Compliance).","Mandatory action: physical removal from service of the specified roller rockers, implying parts replacement and labour costs borne by operators — (Requirement; Background).","Reference linkage: directive refers to FAA AD 98-01-08 for related technical detail, requiring cross-reference for full remediation guidance — (Note 2).","Clear safety rationale: failure mode (roller rocker failure causing oil loss and engine power loss) is stated as the basis for the directive — (Background)."],"plain_english_summary":"This airworthiness directive requires removal from service of “Performance Engineering” exhaust valve roller rockers fitted under FAA STC SE8594SW on certain Teledyne Continental Motors piston engines because of manufacturing errors that have caused roller rocker failures leading to oil loss and possible engine failure. It applies only to engines retrofitted by that STC (not standard TCM rockers) and obliges aircraft owners/operators to remove the affected parts within 25 hours time-in-service from 23 April 1998, creating an immediate maintenance and cost obligation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-con-78-roller-rockers","history":"/api/acts/ad-con-78-roller-rockers/history","analysis":"/api/acts/ad-con-78-roller-rockers/analysis","conflicts":"/api/acts/ad-con-78-roller-rockers/conflicts","importantCases":"/api/acts/ad-con-78-roller-rockers/important-cases","documents":"/api/acts/ad-con-78-roller-rockers/documents"}}