{"id":"F2006B07319","name":"AD/TB20/16 - Nose Landing Gear Lever Adjusting Screws","slug":"ad-tb20-16-nose-landing-gear-lever-adjusting-screws","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49345,"registerId":"commonwealth-F2006B07319-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TB20/16 - Nose Landing Gear Lever Adjusting Screws","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) TB20 (Trinidad) Series Aeroplanes\n\n \n\nAD/TB20/16 Nose Landing Gear Lever Adjusting Screws 3/90\n\nApplicability: TB20 and TB21 aircraft with S/Nos 1 to 701 inclusive, S/No 707 and 709 except S/No 664 and 665.\n\n \n\nRequirement: Action in accordance with Aerospatiale Socata TB SB 46/1.\n\n \n\nNote: DGAC AD 89-108-(A) R1 refers.\n\n \n\nCompliance: Unless previously accomplished - Prior to exceeding 100 hours time in service after 22 March 1990.\n\n \n\nBackground: Country of origin AD. To prevent adjusting screws becoming loose.\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 adopts a country-of-origin measure and directs compliance with the manufacturer’s service bulletin for a defined set of TB20/TB21 serial numbers. The text does not expand or narrow the stated technical remedy or the set of affected serial numbers beyond those listed (Applicability; Requirement; Background)."},"complexity_factors":["Narrow technical scope limited to nose landing gear lever adjusting screws (Requirement; Background)","Clear, short compliance window tied to flight hours and a date (Compliance)","Applicability limited to a specific list of serial numbers (Applicability)","Dependence on an external manufacturer service bulletin for procedural detail (Requirement)","No multiple or staged compliance options, inspections, or record-keeping requirements specified in the AD text"],"plain_english_summary":"This instrument mandates inspection and adjustment of the nose-gear lever adjusting screws on specified Aerospatiale (Socata) TB20/TB21 serial numbers, to be done per the manufacturer’s service bulletin within 100 flight hours after 22 March 1990. \n\nIt affects owners/operators of the listed aircraft, who must arrange and bear the maintenance, downtime and any parts costs; the aim is to reduce the risk of screws working loose by following the manufacturer-prescribed procedure."},"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 specific aircraft. It has not expanded beyond its original purpose of preventing loose nose landing gear adjusting screws."},"complexity_factors":["Very short document (under 200 words)","Only 4 substantive paragraphs (Applicability, Requirement, Note, Compliance)","Single cross-reference to manufacturer service bulletin and French DGAC AD","No defined terms section — uses standard aviation terminology","Simple conditional logic: 'Unless previously accomplished' creates one straightforward exception","Clear, unambiguous compliance deadline (100 hours time in service after fixed date)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice for aircraft owners and operators. It applies to specific **Socata TB20 and TB21 Trinidad aeroplanes** (certain serial numbers only).\n\n**What it requires:**\nOwners must follow the instructions in a manufacturer service bulletin (**SB 46/1**) to inspect or fix the **nose landing gear lever adjusting screws**. These screws can work loose, which could affect the landing gear's operation.\n\n**Who must comply:**\nAnyone operating the affected aircraft must complete this work **before the aircraft clocks up 100 flight hours after 22 March 1990** — unless it was already done.\n\n**Why it matters:**\nLoose adjusting screws on the nose landing gear could lead to landing gear failure. This directive ensures the problem is caught and fixed before it becomes dangerous. It references a French aviation safety directive (DGAC AD 89-108-(A) R1), showing Australia is adopting a safety measure already issued in the aircraft's country of origin (France)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws","history":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws/history","analysis":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws/analysis","conflicts":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws/conflicts","importantCases":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws/important-cases","documents":"/api/acts/ad-tb20-16-nose-landing-gear-lever-adjusting-screws/documents"}}