{"id":"F2006B03611","name":"AD/BEA 206/8 - Engine Tachometer - Warning Arc and Placard","slug":"ad-bea-206-8-engine-tachometer-warning-arc-and-placard","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43202,"registerId":"commonwealth-F2006B03611-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEA 206/8 - Engine Tachometer - Warning Arc and Placard","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBeagle B206 Series Aeroplanes\n\nAD/BEA 206/8 Engine Tachometer \\- Warning Arc and Placard 2/72\n\nApplicability: Model B206 Series 2\\. Requirement: Part 1:\n\n    (a) Install a yellow temporary warning arc on the tachometer glass between 2800 and 3140 RPM until modified in accordance with Part 2 of this Directive.\n\n    (b) Install appropriate operational placard adjacent to the engine tachometer with the following wording:\n\n“AVOID CONTINUOUS OPERATION IN YELLOW ARC”\n\nNote: Letters of one eighth inch minimum height shall be used.\n\nPart 2:\n\nInstall a permanent yellow warning arc on the tachometer dial between 2800 and 3140 RPM.\n\nCompliance: For Part 1: Within 50 hours time in service after 29 February 1972.\n\nFor Part 2: At next aircraft major inspection after 29 February 1972, or at next instrument re-installation, whichever occur first.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive, as written, imposes marking and placard requirements on the specified model and sets timing for temporary and permanent installations. The text contains no indication that the directive's scope deviates from that stated purpose (Applicability; Requirement: Part 1 & Part 2; Compliance)."},"complexity_factors":["Narrow applicability (single aircraft model: Beagle B206 Series 2) — reduces scope complexity (Applicability).","Two-part requirement with clear actions (temporary arc + placard, then permanent arc) — straightforward sequence (Requirement: Part 1 & Part 2).","Short, clearly specified compliance windows (within 50 hours; next major inspection or instrument re-installation) — limited timing complexity (Compliance).","Simple physical installation with one prescriptive placard text and minimum letter size (1/8 inch) — low technical complexity (Requirement: Part 1(b); Note).","Potential operational coordination with scheduled maintenance (major inspection or instrument re-installation) — minor logistical complexity (Compliance: Part 2)."],"plain_english_summary":"What this directive changes (mechanical effect)\n\n- Applies to Beagle B206 Series 2 aeroplanes (Applicability).\n- Two-step marking requirement: (Requirement: Part 1 and Part 2)\n  - Part 1(a): Install a temporary yellow warning arc on the engine tachometer glass covering 2800–3140 RPM.\n  - Part 1(b): Install an operational placard next to the tachometer reading exactly: “AVOID CONTINUOUS OPERATION IN YELLOW ARC” (letters at least 1/8 inch high; Note).\n  - Part 2: At the next opportunity, replace the temporary mark with a permanent yellow warning arc on the tachometer dial covering the same RPM band.\n\nWho is affected\n\n- Owners and operators of Beagle B206 Series 2 aeroplanes must perform the installations described above (Applicability; Requirement: Parts 1 & 2).\n\nWhen it must be done (compliance timing)\n\n- Temporary arc and placard (Part 1): must be fitted within 50 hours time in service after 29 February 1972 (Compliance: Part 1).\n- Permanent arc (Part 2): must be fitted at the next aircraft major inspection after 29 February 1972, or at the next instrument re-installation, whichever occurs first (Compliance: Part 2).\n\nOfficial stated purpose and how that translates into action\n\n- The placard text explicitly instructs pilots to avoid continuous operation in the yellow arc. The directive therefore creates a visible, instrument-level restriction on continuous engine operation in the RPM range 2800–3140 RPM by marking that range on the tachometer and requiring a nearby placard (Requirement: Part 1(b); Part 2).\n\nWho pays and who decides\n\n- The aircraft owner/operator bears the cost and responsibility of installing the temporary arc and placard within 50 hours, and of fitting the permanent arc at the next major inspection or when the instrument is re-installed (Requirement: Part 1 & Part 2; Compliance).\n- The directive prescribes what must be installed and the compliance windows; it does not delegate discretionary criteria for compliance timing beyond the two specified triggers (Compliance).\n\nCompliance burden and implementation details\n\n- Burden is an equipment/maintenance action: applying a temporary marking and placard quickly (within 50 flight hours) and installing a permanent dial marking at a routine maintenance event. The placard wording and a minimum letter size (1/8 inch) are specified (Requirement: Part 1(b); Note).\n- The permanent marking is timed to routine maintenance (major inspection) or instrument re-installation, which limits unscheduled downtime but requires coordinations with maintenance scheduling (Compliance: Part 2).\n\nIncentives, trade-offs and likely behavioural effects\n\n- The directive creates a clear instrument-level signal discouraging continuous operation in the 2800–3140 RPM band; operators and pilots are incentivised to avoid sustained flight in that range to comply with the placard instruction and to follow aircraft operating practices (Requirement: Part 1(b)).\n- Costs are likely to be concentrated on individual aircraft owners/operators who must procure labour/materials and schedule the work; benefits (the intended safety signalling) are broad but not quantified in the text.\n- The directive trades a small immediate maintenance action and minor administrative cost for the ongoing presence of a cockpit visual limit; the permanent marking is deferred to routine maintenance to reduce unscheduled downtime (Compliance: Part 2).\n\nImplementation risks and points needing attention\n\n- Installers must ensure the temporary arc covers the exact RPM band 2800–3140 and that the permanent arc matches that band later (Requirement: Part 1(a); Part 2).\n- The placard wording is prescribed and the minimum letter size is stated; incorrect wording or undersized lettering could create non-compliance (Requirement: Part 1(b); Note).\n\nSummary sentence\n\nThis airworthiness directive requires owners/operators of Beagle B206 Series 2 aeroplanes to fit a temporary yellow tachometer arc and a nearby placard warning against continuous operation in 2800–3140 RPM within 50 hours, and to replace the temporary marking with a permanent yellow arc at the next major inspection or instrument re-installation (Requirement: Part 1 & Part 2; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-purpose airworthiness directive focused specifically on tachometer marking for one aircraft model. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined compliance deadlines","Simple two-part structure (temporary vs permanent modification)","No cross-references to other legislation beyond generic 'Civil Aviation Regulations 1998, Part 39'","Single applicability criterion (Model B206 Series 2)","Minimal conditional logic (just 'whichever occurs first' for Part 2 timing)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) for owners and operators of **Beagle B206 Series 2 aircraft**.\n\n**What it does:**\nThe directive requires two modifications to the engine tachometer (the gauge that shows how fast the engine is spinning):\n\n- **Part 1 (temporary fix):** Within 50 hours of flying time after 29 February 1972, owners must:\n  - Paint or stick a **yellow arc on the tachometer glass** covering the range 2800–3140 RPM\n  - Install a **warning placard** next to the gauge saying: *\"AVOID CONTINUOUS OPERATION IN YELLOW ARC\"* (letters must be at least 1/8 inch tall)\n\n- **Part 2 (permanent fix):** At the next major aircraft inspection or when the instrument is reinstalled (whichever comes first), owners must install a **permanent yellow arc on the dial itself** (not just the glass) for the same RPM range.\n\n**Why it matters:**\nOperating the engine continuously between 2800–3140 RPM apparently causes safety problems—likely vibration, overheating, or excessive wear. The yellow arc warns pilots to avoid staying in that range for long periods. This is a **mandatory compliance** item—aircraft cannot legally fly without these modifications done on schedule.\n\n**Who it affects:**\nAnyone operating a Beagle B206 Series 2 aeroplane in Australia (or under Australian registration)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard","history":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard/history","analysis":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard/analysis","conflicts":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard/conflicts","importantCases":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard/important-cases","documents":"/api/acts/ad-bea-206-8-engine-tachometer-warning-arc-and-placard/documents"}}