{"id":"F2006B08228","name":"AD/CESSNA 336/7 - Rear Engine Idle Rpm - Adjustment and Placard Installation","slug":"ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115473,"registerId":"commonwealth-F2006B08228-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 336/7 - Rear Engine Idle Rpm - Adjustment and Placard Installation","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)  Cessna 336 Series Aeroplanes\n\n \n\nAD/CESSNA 336/7 Rear Engine Idle Rpm - Adjustment\n\nand Placard Installation\n\n\n3/72\n\n \n\nApplicability: All models.\n\n \n\nRequirement: 1. Adjust the rear engine idle setting from 600 + 25 RPM to 650 + 25 RPM and readjust the idle mixture accordingly.\n\n \n\n2. Install a permanent placard adjacent to the tachometer as follows: TAXI AND TAKE-OFF\n\nLEAD WITH REAR ENGINE POWER CHECK RPM AND FUEL FLOW.\n\nNote: A suitable placard is detailed in Cessna SL ME71-21.\n\n \n\nCompliance: Within 100 hours time in service after 31 March 1972.\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 safety directive from 1972 addressing a specific technical problem with a specific aircraft type. It has not expanded beyond its original purpose of correcting rear engine idle speed issues in Cessna 336 aircraft."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 substantive requirements (mechanical adjustment + placard installation)","Single applicability clause ('All models') with no exceptions or conditions","No defined terms section","No cross-references to other legislation (only a non-binding reference to a Cessna service letter for placard design)","Simple compliance deadline (fixed date + hours-in-service trigger)","No nested conditions, exceptions, or discretionary powers"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) for **Cessna 336 series aircraft** — twin-engine planes with one engine at the front and one at the rear.\n\n**What it does:**\n- **Raises the idle speed** of the rear engine from 600 RPM (plus or minus 25) to 650 RPM (plus or minus 25), and adjusts the fuel mixture to match\n- **Requires a warning placard** (a permanent label) to be installed next to the engine speed gauge (tachometer) reminding pilots to: *\"TAXI AND TAKE-OFF LEAD WITH REAR ENGINE POWER CHECK RPM AND FUEL FLOW\"*\n\n**Who it affects:**\n- Owners and operators of all Cessna 336 model aircraft\n- Maintenance engineers who service these planes\n\n**Why it matters:**\nThe rear engine on these aircraft was apparently running too slowly at idle, which could cause operational problems during taxiing and take-off. The higher idle speed improves safety margins, and the placard ensures pilots remember to check the rear engine's performance first during critical flight phases. The directive gave operators **100 hours of flying time after 31 March 1972** to make these changes."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The supplied text sets requirements that apply to \"All models\" of Cessna 336 and prescribes two specific actions with a fixed compliance window. The document does not indicate any amendment or narrowing/expansion of scope from an earlier instrument; no evidence in the supplied text shows a change from an original intent."},"complexity_factors":["Narrow, specific technical change limited to two actions (idle rpm adjustment and placard installation).","Clear numeric specification for idle setting (650 ± 25 RPM) reduces interpretive ambiguity.","Single, short compliance timeframe (100 hours TIS after 31 March 1972) — historical and concrete.","Reference to an external service letter (Cessna SL ME71-21) for placard details introduces a minor external-document dependency.","No alternative-method or exemption language present in the supplied text increases straightforwardness but reduces flexibility."],"plain_english_summary":"This directive requires all Cessna 336 aircraft to have the rear engine idle raised slightly and its idle mixture readjusted, and to have a permanent placard beside the tach instructing pilots to “lead with rear engine power” and check RPM/fuel flow. Owners/operators must have qualified maintenance do the work at their expense within 100 hours TIS after 31 March 1972. It changes maintenance settings and cockpit procedures to ensure the prescribed power‑check sequence."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation","history":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation/history","analysis":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation/analysis","conflicts":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation/conflicts","importantCases":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation/important-cases","documents":"/api/acts/ad-cessna-336-7-rear-engine-idle-rpm-adjustment-and-placard-installation/documents"}}