{"id":"F2006B08690","name":"AD/CT7/6 - Propeller Shafts","slug":"ad-ct7-6-propeller-shafts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51852,"registerId":"commonwealth-F2006B08690-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CT7/6 - Propeller Shafts","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 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  General Electric Turbine Engines - CT7 Series\n\n \n\nAD/CT7/6 Propeller Shafts  11/94 DM\n\nApplicability: General Electric Aircraft Engines Models: CT7-5A2, -5A3, -7A, -7A1, -9B, -9B2,\n\n-9C, -9D.\n\n \n\nRequirement: Action in accordance with General Electric CT7-TP Series Service Bulletin Number A72-350 Revision 3 of 9 June 1994.\n\n \n\nNote: FAA AD 94-15-01 refers.\n\n \n\nCompliance: At the next shop visit after 12 September 1994 or before 30 November 1994 whichever occurs first.\n\n \n\nBackground: A one time ultrasonic inspection of a suspect population of propeller shafts for metallurgical defects and the replacement of any found to be faulty is required because of an inflight propeller separation which resulted from a metallurgical defect.\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":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific engine models. It has not expanded beyond its original purpose of mandating inspection and replacement of defective propeller shafts following a known incident."},"complexity_factors":["Single, specific technical requirement (one inspection type)","Only 8 engine models affected — narrow, clearly listed applicability","Simple compliance deadline structure (next shop visit OR fixed date)","No defined terms section, no cross-references to other legislation beyond a single FAA reference note","Background provides clear safety rationale without legal conditionality","Total length: approximately 150 words of substantive content"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific General Electric aircraft engines (the CT7 series) to inspect their propeller shafts for dangerous metal defects.\n\n**What it does:**\n- Orders a one-time **ultrasonic inspection** (a type of scan that detects cracks or flaws inside metal) on propeller shafts in certain engine models\n- Requires replacement of any shafts found to have metallurgical defects\n\n**Who it affects:**\n- Owners and operators of aircraft using these specific General Electric engines: CT7-5A2, -5A3, -7A, -7A1, -9B, -9B2, -9C, and -9D\n- Maintenance organisations servicing these engines\n\n**Why it matters:**\n- An aircraft already suffered an **inflight propeller separation** — meaning the propeller broke off mid-flight due to a metal defect in the shaft\n- This directive prevents the same catastrophic failure from happening again by catching defective shafts before they fail\n\n**When to comply:**\n- At the next scheduled engine shop visit after 12 September 1994, **or** before 30 November 1994 — whichever comes first"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Scope remains focused on the listed CT7 models and a one‑time inspection/replacement per the GE service bulletin. The instrument does not expand obligations beyond the specified engine population or require ongoing inspections (see Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow applicability to listed CT7 engine variants (Applicability).","Single, one‑time mandated action (ultrasonic inspection and replacement) rather than recurring requirements (Requirement; Background).","Clear, short compliance window tied to next shop visit or a fixed date (Compliance).","Procedural dependence on an external manufacturer service bulletin for how to perform the work (Requirement).","Safety‑critical nature: defective parts must be removed and replaced, creating potential parts and downtime costs for operators (Background).","Cross‑reference to an FAA airworthiness directive, indicating harmonisation with foreign regulator action (Note)."],"plain_english_summary":"This airworthiness directive requires operators of specified General Electric CT7 engine models to perform a one‑time ultrasonic inspection of propeller shafts and to replace any shafts found defective, following GE Service Bulletin A72‑350 Revision 3. It must be done at the next shop visit after 12 September 1994 or by 30 November 1994. Aircraft owners/operators pay for and arrange the inspection and any replacements; the measure responds to an in‑flight propeller separation attributed to a metallurgical defect."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ct7-6-propeller-shafts","history":"/api/acts/ad-ct7-6-propeller-shafts/history","analysis":"/api/acts/ad-ct7-6-propeller-shafts/analysis","conflicts":"/api/acts/ad-ct7-6-propeller-shafts/conflicts","importantCases":"/api/acts/ad-ct7-6-propeller-shafts/important-cases","documents":"/api/acts/ad-ct7-6-propeller-shafts/documents"}}