{"id":"F2009L01328","name":"AD/M20/18 - Nose Gear Steering Horn Assembly Steering Shaft - Replacement - CANCELLED","slug":"ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":122335,"registerId":"commonwealth-F2009L01328-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Mooney M20 Series Aeroplanes","sectionType":"division","heading":"Mooney M20 Series Aeroplanes","content":"### Mooney M20 Series Aeroplanes\n\n| AD/M20/18 | Nose Gear Steering Horn AssemblySteering Shaft - Replacement | 5/2009 |\n| --------- | ------------------------------------------------------------ | ------ |\n\n| Requirement: | CANCELLED.                                                                                                                                                                                                                                                                                                     |\n| ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 7 May 2009.                                                                                                                                                                                                                                                                            |\n| Background:  | This AD was raised in 1972 against Mooney Service Bulletin (SB) No. M20-172. It required a modification to the nose gear steering horn assembly. Compliance was required within 100 hours TIS after 31 October 1972.As all affected aircraft would have been modified long ago, this AD is no longer required. |\n\n![](image.001.png)\n\nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n16 March 2009","sortOrder":0},{"sectionNumber":"AD/M20/18","sectionType":"part","heading":"AD/M20/18","content":"## AD/M20/18","sortOrder":1},{"sectionNumber":"Nose Gear Steering Horn AssemblySteering","sectionType":"part","heading":"Nose Gear Steering Horn AssemblySteering Shaft - Replacement","content":"## Nose Gear Steering Horn Assembly  \nSteering Shaft - Replacement","sortOrder":2},{"sectionNumber":"5/2009","sectionType":"part","heading":"5/2009","content":"## 5/2009","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2311},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This instrument reduces regulatory scope by sunsetting an obsolete requirement rather than expanding it. It terminates a 1972 airworthiness directive that is no longer enforceable or relevant because all affected aircraft were modified long ago."},"complexity_factors":["Single operative provision (cancellation only)","No defined terms or interpretation section","No conditional logic, exceptions, or nested provisions","No cross-references to other legislation (only historical reference to the cancelled directive and service bulletin)","Extremely short (under 150 words of substantive content)"],"plain_english_summary":"**What this does:** This document officially cancels a previous aircraft safety rule (Airworthiness Directive AD/M20/18) that applied to Mooney M20 series aeroplanes.\n\n**The original rule:** Issued in 1972, it required aircraft owners to replace or modify the nose gear steering horn assembly (the component that connects the steering controls to the front wheel) within 100 hours of flying time after October 1972.\n\n**Why it matters:** Because all affected aircraft would have complied with this requirement decades ago, the Civil Aviation Safety Authority (CASA) has removed the rule to reduce unnecessary paperwork. If you own a Mooney M20 aircraft, you no longer need to track compliance with this specific directive—though mechanics would have performed the modification back in the 1970s.\n\n**Key takeaway:** This is a housekeeping measure that cleans up old safety requirements that are no longer relevant."}},"importantCases":[],"_links":{"self":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled","history":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled/history","analysis":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled/analysis","conflicts":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled/conflicts","importantCases":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled/important-cases","documents":"/api/acts/ad-m20-18-nose-gear-steering-horn-assembly-steering-shaft-replacement-cancelled/documents"}}