{"id":"F2006B06841","name":"AD/SD3-30/4 - Fuselage Frame at Station 340.46 - Modification","slug":"ad-sd3-30-4-fuselage-frame-at-station-340-46-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114706,"registerId":"commonwealth-F2006B06841-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-30/4 - Fuselage Frame at Station 340.46 - Modification","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 SD3-30 Series Aeroplanes\n\n \n\nAD/SD3-30/4 Fuselage Frame at Station 340.46 - Modification 12/81\n\nApplicability: All model SD-330 with S/Nos. referenced in Shorts SB No. SD3-53-43 or with S/Nos. referenced in subsequent issues or revisions of that SB.\n\n \n\nDocument: Shorts SB NO. SD3-53-43.\n\n \n\nCompliance: Within 400 hours time in service after 31 December 1981.\n\n \n\nBackground: Manufacturers inspection of production aircraft has revealed omission of reinforcing plates.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The directive imposes a mandatory retrofit on affected SD-330 aircraft to install reinforcing plates that were omitted in production. That requirement alters the as-built condition of listed aircraft by making the modification compulsory (Background; Applicability; Compliance). The instrument therefore expands the set of airworthiness obligations for those serial-numbered aircraft relative to their original delivered state."},"complexity_factors":["Narrow technical scope limited to a single structural location (fuselage frame at station 340.46)","Applicability tied to serial numbers listed in an external manufacturer service bulletin (requires cross-referencing another document)","Compliance deadline expressed as flight hours after a fixed calendar date (tracking of utilisation required)","Mandatory retrofit based on a manufacturer-detected omission (requires parts, labour and downtime)","Regulatory authority reference (Civil Aviation Regulations 1998, Part 39) implies formal enforcement but does not detail enforcement steps within the text provided"],"plain_english_summary":"This AD mandates installing reinforcing plates at fuselage station 340.46 on certain Shorts SD‑330 aeroplanes identified by serial number in Shorts Service Bulletin SD3‑53‑43 (or later revisions). It must be done within 400 hours TIS after 31 December 1981 because the manufacturer found plates were omitted in production. Owners/operators of listed aircraft must arrange and pay for the retrofit per the service bulletin; applicability is limited to the serial numbers shown in that bulletin."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1981 addressing a specific manufacturing defect. It has not expanded beyond its original purpose of mandating structural reinforcement for a particular aircraft model."},"complexity_factors":["Very short document (approximately 150 words)","Only 4 operative provisions: applicability, document reference, compliance deadline, and background","No defined terms section — relies entirely on external reference to Shorts Service Bulletin SD3-53-43 for technical details","Single, unambiguous compliance action (install reinforcing plates)","No conditional logic, exceptions, or nested provisions","Linear structure with no cross-references to other legislation"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:** It orders owners and operators of **Short SD3-30 series aeroplanes** (a type of regional turboprop aircraft) to install **reinforcing plates** at a specific location on the fuselage frame (called \"Station 340.46\" — essentially a measurement point along the aircraft's body).\n\n**Why it's needed:** The manufacturer discovered during production inspections that some aircraft were built **missing these reinforcing plates**. Without them, the airframe could develop structural weaknesses.\n\n**Who must comply:** Anyone operating an SD-330 aircraft with specific serial numbers listed in **Shorts Service Bulletin SD3-53-43** (or later versions of that bulletin).\n\n**When it must be done:** Within **400 hours of flight time** after 31 December 1981.\n\n**Why it matters:** This is a **safety-critical fix**. Airworthiness Directives are legally binding — operators cannot fly the aircraft until they comply. Missing structural reinforcements could lead to airframe failure in flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification","history":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification/history","analysis":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification/analysis","conflicts":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification/conflicts","importantCases":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification/important-cases","documents":"/api/acts/ad-sd3-30-4-fuselage-frame-at-station-340-46-modification/documents"}}