{"id":"F2006B08220","name":"AD/CESSNA 336/12 Amdt 1 - Vented Fuel Caps - Installation","slug":"ad-cessna-336-12-amdt-1-vented-fuel-caps-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115458,"registerId":"commonwealth-F2006B08220-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 336/12 Amdt 1 - Vented Fuel Caps - 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 336/12\n\nAmdt 1\n\n\nVented Fuel Caps - Installation 9/88\n\n \n\nApplicability: Model 336 with S/Nos. 336-0001 to 336-0195. Requirement:  Install vented fuel cap(s) in accordance with:\n\n1. Cessna SL No. SE 77-6; or\n\n \n\n2. FAA AD 79-10-14, Amendment 39-3475.\n\n \n\nCompliance: Within 100 hours time in service after 31 August 1979; or Before 1 January 1980; whichever is the later.\n\nBackground:  To guard against the possibility of either an obstructed primary vent or sticking of the fuel tank vent valve it has been found necessary to provide secondary venting in the form of vented fuel caps. Due to some misinterpretation of this Directive a note has now been added to disallow the fitting of a placard.\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 narrow, targeted safety directive that has remained focused on its original purpose: mandating vented fuel caps for a specific aircraft model. Amendment 1 merely clarifies that placards are not an acceptable alternative — it does not expand the scope beyond the original safety intent."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (model and serial number range)","Simple binary compliance options (two approved methods)","Single straightforward compliance deadline with clear 'whichever is later' logic","No cross-references to other legislation beyond optional FAA alternative","No nested exceptions or conditional sub-clauses","Amendment 1 adds only one clarifying prohibition (no placards)"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Cessna 336 aircraft.\n\n**Who it affects:** Owners and operators of Cessna Model 336 aeroplanes with serial numbers 336-0001 through 336-0195 (approximately 195 aircraft).\n\n**What it requires:** These aircraft must have **vented fuel caps** installed. These are special fuel caps that allow air to flow into the fuel tank, preventing dangerous pressure build-up.\n\n**Why it matters:** The original fuel system design had a flaw. If the primary fuel tank vent became blocked or the vent valve stuck, it could create a vacuum or pressure problem in the fuel tank. This could lead to fuel starvation (engine stops getting fuel) or structural damage. The vented caps act as a backup safety measure — a \"secondary vent\" — to prevent accidents.\n\n**The specific rules:**\n- **When to comply:** Within 100 hours of flying time after 31 August 1979, OR before 1 January 1980 — whichever comes later (giving operators a window to schedule the work).\n- **How to comply:** Follow either Cessna Service Letter SE 77-6 or the equivalent US Federal Aviation Administration directive (FAA AD 79-10-14).\n- **Important note:** You cannot just put a warning placard (sign) on the aircraft instead of installing the caps. This amendment specifically bans that shortcut."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment does not expand applicable aircraft or require additional hardware beyond vented caps; it adds a clarifying note disallowing the fitting of a placard because of prior misinterpretation (Background). Applicability, required method (Cessna SL or FAA AD) and compliance timeframe remain unchanged (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability to specific serial-numbered airframes (Applicability) — reduces scale but requires serial verification.","Prescriptive reliance on external documents (Cessna SL No. SE 77-6; FAA AD 79-10-14) — adds procedural dependency and potential cross-reference ambiguity (Requirement).","Dual compliance deadline formula (within 100 hours after 31 Aug 1979 or before 1 Jan 1980, whichever is later) — scheduling complexity for operators with varying flight hours (Compliance).","Technical installation work — requires qualified maintenance actions and parts procurement (implicit in Requirement).","Amendment clarifying prohibition on a placard due to prior misinterpretation — indicates earlier implementation ambiguity and a residual interpretation risk (Background)."],"plain_english_summary":"Requires owners/operators of Cessna 336 aircraft S/N 336-0001–336-0195 to install vented fuel caps in accordance with Cessna SL No. SE 77-6 or FAA AD 79-10-14 (Requirement). The Civil Aviation Safety Authority issues this directive; compliance is due within 100 hours after 31 August 1979 or before 1 January 1980, whichever is later (Compliance). The change provides secondary tank venting to guard against blocked or sticking vents and the amendment forbids fitting a placard (Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation","history":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation/history","analysis":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation/analysis","conflicts":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation/conflicts","importantCases":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation/important-cases","documents":"/api/acts/ad-cessna-336-12-amdt-1-vented-fuel-caps-installation/documents"}}