{"id":"F2006B02182","name":"AD/AC-112/12 - Rudder Rib - Inspection","slug":"ad-ac-112-12-rudder-rib-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41412,"registerId":"commonwealth-F2006B02182-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC-112/12 - Rudder Rib - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: CASA Airworthiness Directive\nmeta-generator: Aspose.Words for .NET 22.10.0\nmeta-keywords: Issue 3/1982,Aircraft below 5700 kg,Gulfstream (Rockwell) 112 Series Aeroplanes,Rudder Rib - Inspection,12\ntitle: Airworthiness Directive - AD/AC-112/12 - Rudder Rib - Inspection\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)  Gulfstream (Rockwell) 112 Series Aeroplanes\n\n \n\nAD/AC-112/12 Rudder Rib - Inspection 3/82\n\nApplicability: Models 112 and 112B S/Nos. 3 to 544 and 13000.\n\n \n\nModels 112TC and 112TCA S/Nos. 13001 to 13309. Document: Gulfstream American Service Bulletin No. SB-112-68.\n\nCompliance: Unless already accomplished within the last 100 hours’ time in service, inspect IAW Part I before further flight and thereafter at intervals not exceeding 100 hours’ time in service until Part II is accomplished.\n\n \n\nBackground:  In service reports of cracks in rudder tip rib at balance weight attachment hole have been received by the manufacturer.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1736},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive addresses a specific, isolated safety issue regarding structural cracks in a particular aircraft model's rudder. There is no indication of scope expansion beyond the original airworthiness concern."},"complexity_factors":["References external technical document (Gulfstream Service Bulletin SB-112-68) without reproducing its contents","Uses aviation-specific abbreviations (IAW - In Accordance With, S/Nos - Serial Numbers)","Technical terminology requiring specialized knowledge (rudder tip rib, balance weight attachment hole, time in service)","Simple conditional compliance structure with recurring intervals"],"plain_english_summary":"**What this is:** A mandatory safety instruction (called an Airworthiness Directive) for owners of specific light aircraft—the Gulfstream (formerly Rockwell) 112 series, including the 112, 112B, 112TC, and 112TCA models with serial numbers between 3 and 13309.\n\n**What it requires:** Operators must inspect the **rudder rib**—a structural part of the tail fin that helps steer the aircraft—specifically near where balance weights are attached. Cracks have been discovered in this area during normal use.\n\n**When to comply:**\n- If the inspection hasn't been done in the last 100 flight hours, it must be completed before the aircraft flies again.\n- After that, the inspection must be repeated every 100 flight hours until a permanent repair (referred to as \"Part II\" of the manufacturer's instructions) is installed.\n\n**Why it matters:** Cracks in the rudder structure could compromise the pilot's ability to control the aircraft, posing a serious safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-112-12-rudder-rib-inspection","history":"/api/acts/ad-ac-112-12-rudder-rib-inspection/history","analysis":"/api/acts/ad-ac-112-12-rudder-rib-inspection/analysis","conflicts":"/api/acts/ad-ac-112-12-rudder-rib-inspection/conflicts","importantCases":"/api/acts/ad-ac-112-12-rudder-rib-inspection/important-cases","documents":"/api/acts/ad-ac-112-12-rudder-rib-inspection/documents"}}