{"id":"F2006B07283","name":"AD/TB10/16 - Lower Engine Cowl Carburettor Air Supply","slug":"ad-tb10-16-lower-engine-cowl-carburettor-air-supply","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49234,"registerId":"commonwealth-F2006B07283-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB10/16 - Lower Engine Cowl Carburettor Air Supply","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)  Aerospatiale (Socata) TB9 and TB10 (Tobago) Series Aeroplanes\n\n \n\nAD/TB10/16 Lower Engine Cowl Carburettor Air Supply 3/91\n\nApplicability: All TB9 & TB10 series aircraft from S/No’s 1 to 944 inclusive fitted with lower cowling carburettor air supply.\n\nRequirement: Action in accordance with the technical requirements of DGAC AD 90-240 (A). Compliance:              As specified in the Requirement Document with revised effective date of 31 March\n\n1991.\n\n \n\nBackground: The lower engine cowl `NACA’ fitting can be damaged if the supply hose clamp is overtightened. If the fitting is damaged the intake hose could come loose possibly restricting engine operation.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection/repair of the NACA fitting overtightening issue."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (aircraft series and serial number range)","Single technical requirement referencing an external document (DGAC AD 90-240 (A))","No nested conditions, exceptions, or cross-references to other legislation","Straightforward compliance deadline with no alternative methods or phased implementation","Minimal regulatory machinery — essentially a 'do this by this date' instruction"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Socata TB9 and TB10 Tobago aeroplanes** (serial numbers 1 through 944) to inspect and potentially fix a problem with the **carburettor air supply hose** located in the lower engine cowling.\n\n**The safety problem:**\nThe metal fitting that connects the air supply hose (called a 'NACA' fitting) can be damaged if mechanics overtighten the hose clamp. If this fitting is damaged, the hose can come loose and potentially **choke the engine** — a serious flight safety risk.\n\n**What must be done:**\nAircraft owners must follow the technical instructions in a French aviation safety document (**DGAC AD 90-240 (A)**) — the French aviation authority originally identified this problem. The work must be completed by **31 March 1991**.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains Socata TB9 or TB10 aircraft with the lower cowl carburettor air supply system fitted.\n\n**Why it matters:**\nAirworthiness Directives are legally binding. Ignoring this directive means the aircraft cannot be considered airworthy and cannot legally fly in Australian airspace."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text provides no indication that the scope has been altered from an earlier instrument. The AD as published applies to TB9 and TB10 aircraft S/No 1–944 fitted with a lower cowling carburettor air supply and requires action in accordance with DGAC AD 90-240(A) by the stated effective date. There is no wording in this document that purports to expand or narrow those stated applicability limits or the required technical reference; therefore there is no basis in the supplied text to conclude the scope has changed."},"complexity_factors":["Narrow applicability: specific models (TB9 & TB10), serial numbers 1–944, and only aircraft with lower cowling carburettor air supply (Applicability).","Dependence on an external technical document (DGAC AD 90-240(A)) — the AD does not include the technical steps itself (Requirement).","Reference to a separate Requirement Document and a specific compliance date (revised effective date 31 March 1991) creates a procedural step to obtain and follow that document (Requirement; Compliance).","Limited technical detail in the AD text — implementers must interpret and apply the external DGAC instruction to their aircraft, which may require engineering judgement or maintenance approval.","Safety risk described is narrow and component-specific (NACA fitting and intake hose), reducing substantive regulatory complexity but concentrating technical work on maintenance/repair actions (Background)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Aerospatiale (Socata) TB9 and TB10 aeroplanes (serials 1–944) fitted with a lower-cowling carburettor air supply to carry out the inspections/repairs specified in DGAC AD 90‑240(A) (per the published Requirement Document) by the revised effective date (31 March 1991). It responds to a risk that overtightened carburettor hose clamps can damage the NACA fitting, allowing the intake hose to loosen and possibly restrict engine operation; costs fall to operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply","history":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply/history","analysis":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply/analysis","conflicts":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply/conflicts","importantCases":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply/important-cases","documents":"/api/acts/ad-tb10-16-lower-engine-cowl-carburettor-air-supply/documents"}}