{"id":"F2006B05037","name":"AD/CESSNA 180/21 Amdt 1 - Main Spar and Lower Skin","slug":"ad-cessna-180-21-amdt-1-main-spar-and-lower-skin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44947,"registerId":"commonwealth-F2006B05037-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/21 Amdt 1 - Main Spar and Lower Skin","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 180, 182 and Wren 460 Series Aeroplanes\n\n \n\nAD/CESSNA 180/21\n\nAmdt 1\n\n\nMain Spar and Lower Skin 11/67\n\n \n\nApplicability: All models in agricultural category.\n\n \n\nRequirement: Carry out a visual inspection for cracking of the wings in the following areas:\n\n \n\n1. The corners of the skin cutouts through which the lift strut fork passes.\n\n\n \n\n2.    All visible elements of the main spar lower flange front and rear faces in the region of the lift strut attachment.\n\n \n\nParticular attention should be paid to the areas around the spar to skin rivets. The affected areas must be thoroughly cleaned before inspection.\n\n \n\nCompliance: Before 4000 hours component time in service and thereafter at intervals not exceeding 100 hours time in service.\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":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive focused on a specific structural failure mode in a defined aircraft type. The scope remains precisely limited to wing inspections for cracking in agricultural-category Cessna aircraft, consistent with the original purpose of preventing catastrophic wing failure."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined inspection areas with clear physical descriptions","Single compliance pathway with straightforward time-in-service triggers (4000 hours initial, 100 hours recurring)","No cross-references to other legislation or regulations","No conditional exceptions or nested logic","Minimal defined terms (only 'component time in service' requires basic aviation knowledge)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Cessna agricultural aircraft (Cessna 180, 182, and Wren 460 series used in farming operations) to inspect the wings for dangerous cracks in two specific areas:\n- Where the lift strut (the metal brace that supports the wing) passes through the wing skin\n- The main spar's lower flange (the bottom edge of the wing's main structural beam) near where the strut attaches\n\n**Who it affects:**\nAnyone operating these specific Cessna models in agricultural work (crop dusting, aerial spraying, etc.).\n\n**Why it matters:**\nCracks in these areas can lead to **structural failure of the wing** — potentially causing the wing to break off in flight. The directive requires:\n- First inspection before the aircraft reaches 4,000 flight hours\n- Repeat inspections every 100 flight hours after that\n\nThe areas must be cleaned before inspection so cracks aren't hidden by dirt or grime."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument imposes inspection requirements for the specified agricultural‑category aircraft. The text does not indicate any expansion or narrowing of scope beyond those models and the listed inspection areas."},"complexity_factors":["Narrow applicability: applies only to Cessna 180/182 and Wren 460 series in the agricultural category (straightforward scope).","Specific inspection locations: corners of skin cutouts for lift‑strut fork and main spar lower flange faces (requires targeted visual checks).","Mandatory preparatory step: affected areas must be thoroughly cleaned before inspection (adds time and access requirements).","Clear compliance timing: one inspection before 4,000 hours component time, then recurring at ≤100‑hour intervals (regular, easily scheduled cadence).","Remedial action not specified in the text: AD prescribes inspection and detection, leaving subsequent repair decisions to operators/maintenance organisations.","Practical enforcement/recording burden implied: recurring inspections increase ongoing maintenance tracking and potential downtime."],"plain_english_summary":"Requires owners/operators of Cessna 180/182 and Wren 460 series aeroplanes in the agricultural category to perform visual inspections for cracking at the wing lift‑strut fork skin cutouts and the main spar lower flange (front and rear faces near the lift‑strut attachment). Affected areas must be cleaned before inspection. Inspections are required before 4,000 hours component time and then at intervals not exceeding 100 hours. The cost and effort of inspection, cleaning and any repairs fall on aircraft operators and maintainers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin","history":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin/history","analysis":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin/analysis","conflicts":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin/conflicts","importantCases":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin/important-cases","documents":"/api/acts/ad-cessna-180-21-amdt-1-main-spar-and-lower-skin/documents"}}