{"id":"F2006B07625","name":"AD/Z 526/2 - Main Wing Spar Corrosion","slug":"ad-z-526-2-main-wing-spar-corrosion","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":50354,"registerId":"commonwealth-F2006B07625-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/Z 526/2 - Main Wing Spar Corrosion","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)  Morovan Zlin Z 526 Series Aeroplanes\n\n \n\nAD/Z 526/2 Main Wing Spar Corrosion 11/96\n\nApplicability: All models Z 526 aircraft.\n\n \n\nRequirement: Inspect in accordance with Morovan Mandatory Service Bulletin Z 526/69a.\n\n \n\nNote: Czech CAI AD 2-016/96 refers.\n\n \n\nCompliance: Before 10 November 1996, and thereafter at intervals not to exceed 12 months.\n\n \n\nBackground:  The Czech civil aviation authority received reports of exfoliation corrosion on the main wing spar flanges which seriously degraded the structural strength of the wing.\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":3,"scope_assessment":{"changed":false,"description":"The directive’s scope is limited to all models of the Morovan Zlin Z 526 and requires inspections per the manufacturer’s mandatory service bulletin. The text shows no expansion or narrowing of scope from its stated purpose (to address reported exfoliation corrosion on the main wing spar flanges); it prescribes inspection timing and references the service bulletin for technical detail (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow, single-subject directive: one mandatory action (inspection) targeted at a specific aircraft model.","Dependence on an external technical document (Morovan Mandatory Service Bulletin Z 526/69a) for the detailed inspection procedure and any corrective actions.","Recurring compliance requirement (annual inspections) creates ongoing administrative and operational burden.","Reference to a foreign authority (Czech CAI AD 2-016/96) means implementers may need to consult additional documents for context.","Technical assessment of ‘‘exfoliation corrosion’’ requires specialist maintenance/inspection skills even though the AD itself is short."],"plain_english_summary":"What this directive does (mechanics)\n\n- Applies to: all Morovan Zlin Z 526 aircraft (\"Applicability\").\n- Action required: inspect the main wing spar in accordance with Morovan Mandatory Service Bulletin Z 526/69a (\"Requirement\").\n- Timing: complete the inspection before 10 November 1996, and then repeat the inspection at intervals not exceeding 12 months (\"Compliance\").\n- References: the directive notes the related Czech authority AD 2-016/96 (\"Note\").\n- Reason given: the Czech civil aviation authority reported exfoliation corrosion on main wing spar flanges that seriously reduced wing structural strength (\"Background\").\n\nWho is affected and who decides\n\n- The owners/operators of Z 526 aeroplanes are the parties required to carry out the inspections because the AD applies to all Z 526 models and mandates inspection (Applicability; Requirement; Compliance).\n- The Civil Aviation Safety Authority (CASA) issues the airworthiness directive and prescribes compliance timing; the technical inspection procedure and any remedial work are to follow the manufacturer’s Mandatory Service Bulletin Z 526/69a (Requirement).\n\nPractical effects, costs and incentives\n\n- Compliance imposes a recurring operational and maintenance obligation: an initial inspection by 10 November 1996 and then inspections at least once every 12 months (Compliance). Those inspections consume technician time and aircraft availability and therefore impose direct costs on owners/operators (Applicability; Requirement; Compliance).\n- The AD directs operators to follow the manufacturer’s mandatory service bulletin. That bulletin will set the inspection method and any corrective actions; complying therefore requires access to and execution of the procedures in the service bulletin (Requirement).\n- The stated safety rationale is that exfoliation corrosion had been reported and that it can seriously degrade wing strength; the inspection requirement is the chosen mitigation measure (Background).\n\nImplementation, discretion and risks\n\n- The AD is prescriptive about timing but relies on an external document (Morovan Mandatory Service Bulletin Z 526/69a) for technical detail, so executors must consult that bulletin to know exactly what to inspect and how to act (Requirement).\n- The directive references an overseas authority’s finding (Czech CAI AD 2-016/96), indicating CASA relied on that report as part of the justification (Note).\n- Recurring inspections trade a predictable, ongoing maintenance cost against the objective of detecting corrosion early. The AD does not itself describe the corrective steps to be taken if corrosion is found—those steps are provided in the service bulletin (Requirement).\n\nNet operational effect (plain terms)\n\n- Owners/operators of Z 526 aircraft must inspect the main wing spar per the manufacturer’s mandatory bulletin by the specified initial date and then at least annually. The immediate consequence is a recurring maintenance obligation and the need to follow the manufacturer’s procedures for inspection and any corrective action."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific airworthiness issue (wing spar corrosion) in a specific aircraft type. It has not expanded beyond its original purpose; it remains a narrow technical maintenance requirement."},"complexity_factors":["Extremely short document (under 200 words)","Only 1 substantive requirement (inspect per service bulletin)","Single applicability criterion (all Z 526 models)","Simple compliance timeline (once by date, then annually)","No defined terms section, no cross-references to other legislation beyond a single note referencing a Czech AD","No conditional logic, exceptions, or nested provisions"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to all **Morovan Zlin Z 526 series aircraft** (a type of Czech-made aeroplane).\n\n**What it requires:**\n- Owners and operators must **inspect the main wing spar** (the central structural beam that holds the wings together) for **corrosion damage** — specifically a type called \"exfoliation corrosion\" that eats away at the metal and weakens the wing structure.\n- The inspection must follow a specific technical document: **Morovan Mandatory Service Bulletin Z 526/69a**.\n\n**When it must be done:**\n- **First inspection:** Before 10 November 1996\n- **Repeat inspections:** Every 12 months thereafter\n\n**Why it matters:**\nThe Czech aviation authority discovered that corrosion on the wing spar flanges (the edges of the beam) was **seriously degrading the structural strength of the wing**. This creates a genuine risk of wing failure in flight. The directive forces operators to check for this hidden damage before it becomes catastrophic.\n\n**Key point:** This isn't optional advice — it's **legally enforceable**. Flying an aircraft without complying with an AD can ground the plane and expose the operator to penalties."}},"importantCases":[],"_links":{"self":"/api/acts/ad-z-526-2-main-wing-spar-corrosion","history":"/api/acts/ad-z-526-2-main-wing-spar-corrosion/history","analysis":"/api/acts/ad-z-526-2-main-wing-spar-corrosion/analysis","conflicts":"/api/acts/ad-z-526-2-main-wing-spar-corrosion/conflicts","importantCases":"/api/acts/ad-z-526-2-main-wing-spar-corrosion/important-cases","documents":"/api/acts/ad-z-526-2-main-wing-spar-corrosion/documents"}}