{"id":"F2006B11258","name":"AD/M20/6 - Installation of Engine Speed Restriction Placard","slug":"ad-m20-6-installation-of-engine-speed-restriction-placard","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57036,"registerId":"commonwealth-F2006B11258-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/M20/6 - Installation of Engine Speed Restriction Placard","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)  Mooney M20 Series Aeroplanes\n\n \n\nAD/M20/6 Installation of Engine Speed Restriction Placard 8/65\n\nApplicability: All model M20E with S/Nos. 101 to 722. Document:  Mooney SB 20-127.\n\nCompliance: Forthwith.\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 \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive from 1965 (as indicated by '8/65' in the identifier) addressing a specific technical issue with a specific aircraft model. It has not expanded beyond its original narrow purpose of mandating a cockpit placard for engine speed limitation."},"complexity_factors":["Extremely short document (under 100 words of substantive content)","No defined terms section","No cross-references to other legislation beyond a single manufacturer document reference","Simple unconditional directive: single applicability criterion, single action required, immediate compliance","No exceptions, exemptions, or conditional logic"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety notice issued by the Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it requires:** Owners and operators of certain Mooney M20E aeroplanes (serial numbers 101 to 722) must install a placard (a visible warning sign) in the cockpit that restricts engine speed. This follows a service bulletin from the manufacturer (Mooney Service Bulletin 20-127).\n\n**Who it affects:** Anyone who owns, operates, or maintains Mooney M20E aircraft with those specific serial numbers.\n\n**When it must be done:** Immediately (\"forthwith\"). This is not optional and cannot be deferred.\n\n**Why it matters:** Engine speed restrictions prevent mechanical failure that could lead to loss of control or engine damage. The placard ensures pilots are visually reminded of operational limits every time they fly. Ignoring this directive makes the aircraft unairworthy — meaning it cannot legally fly until fixed."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD's scope is narrow and clearly stated in the instrument itself: it applies to Mooney M20E aircraft with serial numbers 101 to 722 and requires installation of an engine speed restriction placard per Mooney SB 20-127, with compliance required forthwith. The text contains no indication that the stated applicability or required action has been expanded or altered from the instrument's own expressed scope."},"complexity_factors":["Narrow, well-defined applicability (single model and specific serial number range). (Applicability)","Single, discrete required action (install a placard). (AD title)","Immediate compliance timeframe ('Forthwith') increases urgency but not technical complexity. (Compliance)","Reliance on an external document (Mooney SB 20-127) for technical detail introduces a dependency outside the AD text. (Document: Mooney SB 20-127)","AD text is terse and omits procedural specifics (who certifies the work, exact placard wording), requiring implementers to consult the referenced service bulletin. (Document: Mooney SB 20-127)"],"plain_english_summary":"### What the instrument requires, mechanically\n- This Airworthiness Directive (AD/M20/6 — \"Installation of Engine Speed Restriction Placard\", 8/65) requires that an engine speed restriction placard be installed on certain Mooney M20E aeroplanes. (AD/M20/6; Applicability)\n- The AD applies to all Mooney M20E aircraft with serial numbers 101 through 722. (Applicability)\n- The technical method or wording for the placard to be fitted is given by the referenced manufacturer service bulletin: Mooney SB 20-127. (Document: Mooney SB 20-127)\n- Compliance is mandatory immediately; the AD states \"Forthwith.\" (Compliance)\n\n### Who pays and who must act\n- Owners and operators of the affected aircraft must arrange for the placard to be installed. The AD itself sets the requirement; the owner/operator bears the time and any direct costs of obtaining and fitting the placard. (Applicability; Compliance)\n- Maintenance organisations or certificated mechanics who perform the work will incur the labour time and may charge for that service; they must follow the instructions in Mooney SB 20-127. (Document: Mooney SB 20-127)\n\n### Why it matters (as stated and as mechanically implied)\n- The title and the required action indicate the placard is intended to convey an engine speed restriction (the AD is titled \"Installation of Engine Speed Restriction Placard\"). The AD text itself does not set out the safety analysis or operational history that led to the requirement. (AD title)\n- Mechanically, the AD creates a new, immediate mandatory equipment/placarding obligation for the subset of M20E aircraft listed. (Applicability; Compliance)\n\n### Implementation, incentives and practical effects\n- The compliance obligation is immediate (\"Forthwith\"), which creates an incentive for owners/operators to schedule the placard installation promptly to remain compliant and airworthy. (Compliance)\n- The AD delegates the technical specification to a manufacturer service bulletin (Mooney SB 20-127). That means the manufacturer’s bulletin controls the detailed method and appearance of the placard; compliance requires following that external document. (Document: Mooney SB 20-127)\n- Costs are direct and concentrated on the owners/operators of the affected aircraft (purchase/manufacture of the placard, labour to fit it, and any administrative time for compliance). Maintenance providers may receive business from performing the work. (Applicability; Compliance)\n- Because the AD provides minimal procedural detail within its text, implementers must refer to the service bulletin for specifics. That creates a reliance on the manufacturer document for correct compliance and reduces interpretive discretion for the owner/operator. (Document: Mooney SB 20-127)\n\n### Trade-offs, risks and compliance burden (mechanical view)\n- Trade-offs: the AD imposes a small, discrete installation task in exchange for whatever operational constraint the placard is intended to communicate (the AD text does not quantify benefits or operational impacts). (AD title)\n- Compliance burden: the burden appears limited in scope (installing a placard) but is mandatory and immediate; timing and access to approved mechanics may create temporary operational disruption. (Compliance)\n- Implementation risk and discretion: the AD leaves technical detail to the manufacturer bulletin, so correct implementation depends on that bulletin and on correct execution by the party performing the installation. The AD itself does not describe enforcement mechanisms or exemptions. (Document: Mooney SB 20-127; Compliance)\n\n### Where the AD is specific and where it is silent\n- Specific: the affected models/serial numbers, the requirement to install a placard, the service bulletin reference, and the immediate compliance time. (Applicability; Document; Compliance)\n- Silent: the AD text does not include the placard wording, the reasons or evidence for the requirement, estimated costs, who must certify the work, or details on enforcement or record-keeping. Those details would be in Mooney SB 20-127 or in other regulatory guidance. (AD text; Document: Mooney SB 20-127)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard","history":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard/history","analysis":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard/analysis","conflicts":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard/conflicts","importantCases":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard/important-cases","documents":"/api/acts/ad-m20-6-installation-of-engine-speed-restriction-placard/documents"}}