{"id":"F2006B05189","name":"AD/CESSNA 190/4 - Upper Landing Gear Bulkhead","slug":"ad-cessna-190-4-upper-landing-gear-bulkhead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45364,"registerId":"commonwealth-F2006B05189-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 190/4 - Upper Landing Gear Bulkhead","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 190 and 195 Series Aeroplanes\n\n \n\nAD/CESSNA 190/4 Upper Landing Gear Bulkhead 9/73\n\nApplicability: All models 190 and 195.\n\n \n\nRequirement: Action in accordance with Cessna SL SE73-15.\n\n \n\nCompliance: Within 25 hours time in service after 28 September 1973 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\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD text shows no change of scope from its stated elements: it applies to all Cessna 190 and 195 models and mandates the actions set out in Cessna SL SE73-15 within the specified initial and recurring timeframes (Applicability; Requirement; Compliance). The directive does not expand or narrow applicability beyond those statements."},"complexity_factors":["Reference to an external document (Cessna SL SE73-15) that is not reproduced in the AD (Requirement)","Short initial compliance window (within 25 hours time in service after 28 September 1973) (Compliance)","Recurring maintenance interval requirement (every ≤100 hours TIS) imposing ongoing scheduling and cost obligations (Compliance)","Broad applicability to all models 190 and 195, creating a wide set of affected operators (Applicability)","AD prescribes compliance but does not include technical details, requiring reliance on the separate service letter (Requirement)","Legal placement within the Schedule of Airworthiness Directives under Part 39, which establishes its regulatory authority (header text)"],"plain_english_summary":"This airworthiness directive requires owners and operators of all Cessna 190 and 195 aeroplanes to perform the maintenance specified in Cessna Service Letter SE73-15 (the service letter is not reproduced in the AD). The action must be done within 25 hours TIS after 28 Sept 1973 and repeated at intervals not exceeding 100 hours TIS; owners/operators and maintenance providers must arrange and fund compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on the upper landing gear bulkhead of two specific aircraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 4 operative provisions: applicability, requirement, compliance, and reference to external document","No defined terms section — relies on standard aviation terminology","Single cross-reference to Cessna Service Letter SL SE73-15 (external technical document)","Simple temporal compliance structure (initial + recurring intervals)","No conditional logic, exceptions, or nested provisions"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of Cessna 190 and 195 series aircraft to inspect or repair the **upper landing gear bulkhead** — a structural component where the landing gear attaches to the airframe. The work must follow specific instructions in a Cessna Service Letter (SL SE73-15).\n\n**Who it affects:** Anyone who owns, operates, or maintains Cessna 190 or 195 model aircraft in Australia.\n\n**Why it matters:** Landing gear bulkheads are critical structural parts. If they fail, the landing gear could collapse during takeoff or landing. This AD was issued to prevent accidents caused by structural fatigue or damage in this area.\n\n**What must be done:**\n- **First inspection:** Within 25 hours of flying time after 28 September 1973\n- **Ongoing checks:** Every 100 hours of flying time thereafter\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A legally enforceable safety notice that requires aircraft owners to complete specific maintenance actions\n- **Time in service:** Actual flight hours (not calendar time)\n- **Service Letter:** Manufacturer's technical instructions for maintenance or inspection"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead","history":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead/history","analysis":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead/analysis","conflicts":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead/conflicts","importantCases":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead/important-cases","documents":"/api/acts/ad-cessna-190-4-upper-landing-gear-bulkhead/documents"}}