{"id":"F2006B07069","name":"AD/SM-260/10 - Fuselage Lower Skin - Modification","slug":"ad-sm-260-10-fuselage-lower-skin-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48820,"registerId":"commonwealth-F2006B07069-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SM-260/10 - Fuselage Lower Skin - 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 260 Series Aeroplanes\n\n \n\nAD/SM-260/10 Fuselage Lower Skin - Modification 2/78\n\nApplicability: All models.\n\n \n\nDocument: 1. RAI AD No. 78-22/F260-23. or\n\n \n\n2. SIAI Marchetti SB No. 260B28.\n\n \n\nCompliance: Within 100 hours time in service after 30 April 1978.\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":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Based solely on the AD text provided, there is no indication that the scope of affected aircraft or the required modification was changed from the instrument's original stated direction. The AD explicitly applies to all models (Applicability) and mandates the modification per one of two referenced documents within the specified hours-in-service window (Document; Compliance). The text contains no amendment language or limiting qualifiers that would indicate a change in scope from an earlier statement."},"complexity_factors":["Mandated compliance window measured in flight hours rather than calendar date (Compliance) — requires tracking flight hours and scheduling work accordingly.","Applicability to all models (Applicability) — expands the population of affected aircraft without model-based exclusions.","Technical detail absent from the AD text and delegated to two external documents (Document) — operators must obtain, read and apply those documents to know exact procedures, parts and methods.","Multiple alternative technical documents provided (Document) — choosing which document to follow requires assessment of equivalence and regulatory acceptability.","Historical compliance deadline context (30 April 1978 reference; Compliance) — creates possible ambiguity for records, especially for late-entry registrants or aircraft with incomplete historical time-in-service records."],"plain_english_summary":"### What this directive does (mechanical change)\n\n- This Airworthiness Directive (AD) requires a modification to the fuselage lower skin of SIAI Marchetti 260 series aeroplanes. The AD gives two alternative technical sources that describe how to carry out the modification: RAI AD No. 78-22/F260-23, or SIAI Marchetti Service Bulletin No. 260B28 (Document). (Document)\n- The AD applies to all models of the type (Applicability). (Applicability)\n- The modification must be done within 100 hours time in service after 30 April 1978 (Compliance). (Compliance)\n- The AD is issued under the Commonwealth Civil Aviation Regulations and appears in the Civil Aviation Safety Authority schedule of airworthiness directives (Authority).\n\n### What the text itself says about purpose\n\n- The AD text does not include a description of the safety problem or a statement of operational rationale. Any explanation for why the modification is required must be sought in the referenced documents or other regulatory records. (Document)\n\n### Compliance Requirements and Implementation Detail\n\n- The AD makes the modification mandatory within the specified timeframe (Compliance). (Compliance)\n- The AD requires compliance by following one of two external technical documents; the technical steps, materials, and procedures are defined in those documents rather than in the AD text itself. Operators or maintenance providers must obtain and follow the referenced RAI AD or the SIAI Marchetti service bulletin to perform the work. (Document)\n\n### Costs, incentives and who decides\n\n- Who pays: Aircraft owners or operators (and their maintenance organisations) are the parties responsible for carrying out the modification and therefore bear the direct costs of parts, labour, and any aircraft downtime. (Applicability; Compliance)\n- Who decides how to comply: The owner/operator or their authorised maintenance organisation decides which of the two referenced documents to use to perform the modification, subject to regulatory acceptance. The AD itself does not specify a single mandatory method—two documents are offered as alternatives. (Document)\n- Incentives and trade-offs: Compliance imposes a near-term scheduling cost (must be done within 100 hours TIS after 30 April 1978). Operators weigh the cost and aircraft availability loss of performing the work against the imperative to meet the regulatory deadline. (Compliance)\n\n### Effects on private choice, aftermarket and competition\n\n- Private choice: The AD reduces the set of lawful options for continued operation of affected aeroplanes by requiring an approved modification within the timeframe. Operators retain a choice between the two referenced technical documents for how to implement the work. (Applicability; Document; Compliance)\n- Aftermarket/competition: The AD channels compliance activity to suppliers and maintenance providers who can perform the modification in accordance with one of the two referenced documents. Demand will therefore concentrate on providers that can perform work to those specifications and supply any specified parts. The AD text does not name specific suppliers or require proprietary parts; the external documents are where any parts or supplier specifications would appear. (Document)\n\n### Implementation risks and practical considerations\n\n- The AD does not include the engineering or procedural detail; those details are in the two referenced documents. Operators must obtain and interpret the appropriate document to plan parts, labour, and inspections. (Document)\n- Timing: The 100-hour TIS deadline after 30 April 1978 creates a fixed compliance window measured in flight hours; operators must track hours to ensure compliance. (Compliance)\n\n### Net description of who pays, who decides, and behaviour changes\n\n- Who pays: owners/operators pay for the modification, parts, labour and downtime. (Applicability; Compliance)\n- Who decides: owner/operator or their authorised maintenance organisation decides which referenced document to follow and arranges the work; the regulator enforces the AD under the Civil Aviation Regulations. (Document; Authority)\n- What changes in behaviour: Affected operators must schedule and carry out the fuselage lower skin modification within the specified time; maintenance providers must offer and perform the work to one of the two referenced documents. (Document; Compliance)\n\n(Referenced sections: Applicability; Document; Compliance; Authority.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive from 1978. It has not expanded beyond its original purpose of mandating a specific structural modification to a specific aircraft type. The scope remains precisely as intended: a targeted safety intervention for the SIAI Marchetti 260 series fuselage lower skin."},"complexity_factors":["Extremely short document — only 8 substantive lines","No defined terms section; all language is plain operational English","No cross-references to other legislation beyond the enabling regulation (Part 39)","Simple conditional structure: applicability → document reference → compliance deadline","Single compliance pathway with alternative reference documents (OR structure, not nested)","No exceptions, exemptions, or provisos"],"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) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of **SIAI Marchetti 260 series aeroplanes** (all models) to modify the **fuselage lower skin** — the bottom outer surface of the aircraft's main body. This modification addresses a structural safety issue.\n\n**Who must comply:** Anyone who owns or operates these specific Italian-made light aircraft in Australia.\n\n**How to comply:** You must follow either:\n- **RAI AD No. 78-22/F260-23** (the Italian aviation authority's equivalent directive), **or**\n- **SIAI Marchetti Service Bulletin No. 260B28** (the manufacturer's official repair instructions)\n\n**Deadline:** The work must be completed **within 100 hours of flight time** after 30 April 1978.\n\n**Why it matters:** Airworthiness Directives are legally binding. Flying an aircraft without completing required ADs violates aviation law and can invalidate insurance. This particular directive prevents potential structural failure in the fuselage — critical for passenger safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification","history":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification/history","analysis":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification/analysis","conflicts":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification/conflicts","importantCases":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification/important-cases","documents":"/api/acts/ad-sm-260-10-fuselage-lower-skin-modification/documents"}}