{"id":"F2006B02108","name":"AD/AC/49 - Wing Main Spar - Inspection","slug":"ad-ac-49-wing-main-spar-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41338,"registerId":"commonwealth-F2006B02108-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AC/49 - Wing Main Spar - 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 5/1973,Aircraft below 5700 kg,Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes,Wing Main Spar - Inspection,49\ntitle: Airworthiness Directive - AD/AC/49 - Wing Main Spar - 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)  Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes\n\n \n\nAD/AC/49 Wing Main Spar - Inspection 5/73\n\nApplicability: Model 690 with S/Nos. 11001 to 11021. Compliance:  Within 100 hours’ time in service after 31 May 1973. Document:               Aero Commander SL No. 253.\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\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":1986},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive for a specific aircraft batch. The scope remains narrowly focused on the wing main spar inspection for the identified serial numbers, consistent with the original purpose of addressing a specific airworthiness concern."},"complexity_factors":["Extremely brief directive (under 100 words)","Single, clearly defined applicability criterion (specific aircraft model and serial number range)","Simple compliance condition (time-in-service deadline)","Technical inspection details referenced externally rather than defined within the legislation"],"plain_english_summary":"**What this is:** A mandatory safety instruction (called an *Airworthiness Directive*) requiring a specific structural inspection on certain aircraft.\n\n**Who it affects:** Owners and operators of **Twin Commander Model 690 aircraft** with serial numbers 11001 through 11021 (specific Gulfstream/Rockwell/Aero Commander planes).\n\n**What it requires:** An inspection of the **wing main spar** (the primary structural beam supporting the wing) must be carried out within **100 hours of flight time** after 31 May 1973.\n\n**Why it matters:** The wing main spar is critical to keeping the wing attached to the aircraft. This directive addresses a discovered defect or fatigue issue that could lead to structural failure if not checked.\n\n**Technical details:** The actual inspection procedure is contained in **Aero Commander Service Letter No. 253**, which operators must follow to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ac-49-wing-main-spar-inspection","history":"/api/acts/ad-ac-49-wing-main-spar-inspection/history","analysis":"/api/acts/ad-ac-49-wing-main-spar-inspection/analysis","conflicts":"/api/acts/ad-ac-49-wing-main-spar-inspection/conflicts","importantCases":"/api/acts/ad-ac-49-wing-main-spar-inspection/important-cases","documents":"/api/acts/ad-ac-49-wing-main-spar-inspection/documents"}}