{"id":"F2006B06898","name":"AD/SD3-60/51 - Elevator Control Torque Tube Bearing Housing","slug":"ad-sd3-60-51-elevator-control-torque-tube-bearing-housing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114778,"registerId":"commonwealth-F2006B06898-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-60/51 - Elevator Control Torque Tube Bearing Housing","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)  Short SD3-60 Series Aeroplanes\n\n \n\nAD/SD3-60/51 Elevator Control Torque Tube Bearing Housing 3/99\n\nApplicability: All SD3-60 aircraft.\n\n \n\nRequirement: Action in accordance with Shorts Mandatory Service Bulletin SD360-27-28. Compliance:              Before 25 September 1999.\n\nThis Airworthiness Directive becomes effective on 25 March 1999.\n\n \n\nBackground:  Experience shows that existing bolts securing elevator control torque tube bearing housing retaining plate to pilots seat pedestal have been found loose, probably because the significance of the structure was not recognised during maintenance.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD does not broaden or narrow the set of aircraft addressed beyond the stated applicability. It applies to all SD3-60 aeroplanes and mandates the actions set out in Shorts Mandatory Service Bulletin SD360-27-28 to address loose bolts found on the elevator control torque tube bearing-housing retaining plate (Applicability; Requirement; Background). The instrument therefore implements the corrective action indicated by the background report without changing the stated scope of affected aircraft."},"complexity_factors":["Single, focused obligation: the AD mandates compliance with one specific manufacturer’s Mandatory Service Bulletin (Requirement).","Clear applicability: applies to all SD3-60 aeroplanes (Applicability), which narrows the regulated population.","Fixed compliance window and effective date: explicit effective date (25 March 1999) and a single compliance deadline (before 25 September 1999) reduce procedural ambiguity (Effective date; Compliance).","No technical detail in the AD itself: the AD defers technical specifics to the referenced service bulletin, requiring users to consult another document to know exact tasks (Requirement).","No alternative compliance or exemptions stated in the AD text, leaving limited procedural discretion (Requirement).","Implementation dependencies: actual time, parts and methods depend on the service bulletin content and operator maintenance practices (Requirement; Background)."],"plain_english_summary":"The AD mandates that every Shorts SD3-60 aircraft comply with Manufacturer’s Mandatory Service Bulletin SD360-27-28 by 25 September 1999 (effective 25 March 1999). It was issued after discovery of loose bolts on the elevator control torque-tube bearing-housing retaining plate and makes the service bulletin’s corrective work compulsory.\n\nOwners/operators and their maintenance organisations must arrange and fund the required inspections/repairs, which will cause maintenance downtime and associated costs."},"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 type. It has not expanded beyond its original purpose of mandating a particular maintenance action."},"complexity_factors":["Single, specific mechanical issue addressed","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Simple conditional structure: applicability → requirement → compliance deadline","Only 4 substantive paragraphs (Applicability, Requirement, Compliance, Background)","Relies on external technical document (Service Bulletin) for actual implementation details"],"plain_english_summary":"This is a **safety order for aeroplanes** called an **Airworthiness Directive** (a legally binding instruction issued by aviation safety authorities).\n\n**What it does:**\n- Orders owners and operators of **Short SD3-60 Series aircraft** (a type of small regional aeroplane) to inspect and fix a specific mechanical problem.\n- The problem involves **bolts holding the elevator control mechanism** (the part that makes the plane go up and down) becoming loose.\n- These bolts secure a **bearing housing** (a metal casing that holds moving parts) to the pilot's seat pedestal.\n\n**Why it matters:**\n- Loose bolts in the elevator control system could cause **loss of control** of the aircraft, with potentially catastrophic consequences.\n- The issue arose because maintenance crews didn't realise how important this particular structure was.\n\n**Who must act:**\n- Anyone who owns or operates a Short SD3-60 aircraft.\n\n**What they must do:**\n- Follow the instructions in **Shorts Mandatory Service Bulletin SD360-27-28** (the manufacturer's official repair notice).\n- Complete the work **before 25 September 1999**.\n\n**When it takes effect:**\n- **25 March 1999** (giving operators 6 months to comply)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing","history":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing/history","analysis":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing/analysis","conflicts":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing/conflicts","importantCases":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing/important-cases","documents":"/api/acts/ad-sd3-60-51-elevator-control-torque-tube-bearing-housing/documents"}}