{"id":"F2006B07043","name":"AD/SM-205/20 - Main and Nose Landing Gear Torque Link Pins and Bolts - Modification","slug":"ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48763,"registerId":"commonwealth-F2006B07043-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SM-205/20 - Main and Nose Landing Gear Torque Link Pins and Bolts - 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)  SIAI Marchetti S205 and S208 Series Aeroplanes\n\n \n\nAD/SM-205/20 Main and Nose Landing Gear Torque\n\nLink Pins and Bolts - Modification Applicability: All 205 series with S/Nos. 001 to 003, 101 to 399 and 4-101 to 4-212. Document:               SIAI Marchetti SB 205B35.\n\nCompliance: With 100 hours time in service after 31 July 1972.\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\n\n7/72\n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1972. It has not expanded beyond its original narrow purpose of addressing a specific landing gear defect in specific aircraft."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 defined applicability criteria (aircraft series and serial numbers)","Single compliance requirement with clear deadline","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","No conditional logic, exceptions, or nested provisions","Straightforward command structure: do X by Y date according to Z document"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific SIAI Marchetti aircraft to modify the landing gear.\n\n**What it does:**\n- Orders a safety modification to the **main and nose landing gear torque link pins and bolts** on certain SIAI Marchetti S205 and S208 series aeroplanes.\n- The fix must follow the manufacturer's Service Bulletin (SB 205B35).\n\n**Who it affects:**\n- Owners and operators of SIAI Marchetti 205 series aircraft with serial numbers 001–003, 101–399, and 4-101 to 4-212.\n\n**Why it matters:**\n- Landing gear failures can be catastrophic. This directive addresses a specific mechanical defect before it causes an accident.\n- **Compliance is mandatory** — operators must complete the modification within 100 hours of flight time after 31 July 1972.\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A legally enforceable safety order requiring aircraft owners to fix known unsafe conditions.\n- **Service Bulletin:** Technical instructions from the manufacturer on how to repair or modify an aircraft.\n- **Time in service:** Actual flight hours (not calendar time)."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text supplied is a single airworthiness directive that sets a modification requirement for specified SIAI Marchetti 205 series aircraft and a single compliance timeframe. The excerpt does not indicate any amendment to or expansion of scope beyond what is stated (applicability, reference document, and compliance time). No information in the supplied text shows a change from an earlier stated scope."},"complexity_factors":["Narrow technical scope: single subject (torque link pins and bolts) limited to specific aircraft serial numbers (Applicability line).","Simple, fixed compliance metric: a single deadline expressed as 100 hours time in service after a calendar date (Compliance line).","Reference to an external technical document (SIAI Marchetti SB 205B35) for procedural detail reduces complexity in the AD text but creates dependency on another document for implementation (Document line).","Absence of procedural detail in the AD itself: method, authorised personnel, and parts are not specified in the AD text, which reduces textual complexity but increases operational uncertainty until the service bulletin is consulted.","No multiple options or conditional pathways in the AD: there are no alternative compliance methods or tiered requirements listed."],"plain_english_summary":"What this instrument requires\n\n- The Civil Aviation Safety Authority (CASA) issued an airworthiness directive titled \"AD/SM-205/20 — Main and Nose Landing Gear Torque Link Pins and Bolts - Modification\" (source header).\n- The directive mandates a modification to the main and nose landing gear torque link pins and bolts. The AD refers to SIAI Marchetti Service Bulletin SB 205B35 for the technical modification (\"Document: SIAI Marchetti SB 205B35\").\n\nWho is affected\n\n- The AD applies to SIAI Marchetti 205 series aeroplanes with serial numbers 001 to 003, 101 to 399, and 4-101 to 4-212 (\"Applicability: All 205 series with S/Nos. 001 to 003, 101 to 399 and 4-101 to 4-212\").\n\nWhen it must be done\n\n- The required modification must be carried out within 100 hours time in service after 31 July 1972 (\"Compliance: With 100 hours time in service after 31 July 1972\").\n\nHow it works mechanically\n\n- The AD itself sets the regulatory requirement (an obligation to modify the listed parts). The technical steps, parts, drawings and workshop instructions are referenced to the manufacturer's Service Bulletin SB 205B35 (\"Document: SIAI Marchetti SB 205B35\"), which is the implementing technical document.\n\nWhat the directive implies about incentives, costs and implementation (source-grounded)\n\n- Who pays: The text of the AD does not state who bears the cost of the modification. The AD imposes a requirement on the listed aircraft, so owners/operators of those aircraft are the parties subject to the obligation (see applicability and compliance lines cited above); the AD text itself does not allocate financial responsibility.\n- Decision and enforcement: The AD is issued under the schedule of airworthiness directives by the Civil Aviation Safety Authority (document header). The AD sets a compliance deadline and refers to a manufacturer service bulletin for the technical method; the AD text does not set out enforcement mechanisms or penalties.\n- Compliance burden and discretion: The AD specifies the required action (modification) and an implementation reference (SB 205B35). The AD does not in this text describe who may perform the modification, the parts required, the detailed procedure, or whether alternative methods are acceptable; those technical details are left to the referenced service bulletin (\"Document: SIAI Marchetti SB 205B35\"), which the AD cites as the implementing document.\n- Trade-offs and risks explicitly shown in the text: The AD sets a narrow, time‑limited compliance obligation for a defined set of serial-numbered aircraft. The text does not state estimated costs, operational downtime, availability of parts, or safety justification in this excerpt.\n\nSource citations\n\n- Applicability: \"Applicability: All 205 series with S/Nos. 001 to 003, 101 to 399 and 4-101 to 4-212.\" \n- Implementing document: \"Document: SIAI Marchetti SB 205B35.\" \n- Compliance timing: \"Compliance: With 100 hours time in service after 31 July 1972.\""}},"importantCases":[],"_links":{"self":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification","history":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification/history","analysis":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification/analysis","conflicts":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification/conflicts","importantCases":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification/important-cases","documents":"/api/acts/ad-sm-205-20-main-and-nose-landing-gear-torque-link-pins-and-bolts-modification/documents"}}