{"id":"F2006B05615","name":"AD/PA-28/58 - Wing Structural Fatigue Life Limitation","slug":"ad-pa-28-58-wing-structural-fatigue-life-limitation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135249,"registerId":"commonwealth-F2006B05615-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-28/58 - Wing Structural Fatigue Life Limitation","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)  Piper PA-28 Series Aeroplanes\n\n \n\nAD/PA-28/58 Wing Structural Fatigue Life Limitation 12/76\n\nApplicability: All model PA-28-235. Requirement: Retire the wing from service.\n\nCompliance: At or before 12,500 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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive text sets a specific, limited scope: mandatory retirement of the wing on PA-28-235 aircraft at or before 12,500 hours time in service (Applicability; Requirement; Compliance). The text does not indicate a change from some prior broader or narrower policy; it expresses a single, concrete limitation consistent with its title (Wing Structural Fatigue Life Limitation). No alteration of scope from an earlier intent is evident within the supplied text."},"complexity_factors":["Single, clear operative requirement (retire wing) with a fixed numeric threshold (12,500 hours).","Very narrow applicability (only PA-28-235 models).","Absence of procedural details in the text (no certification, replacement, or enforcement steps specified) which shifts complexity to external procedures and recordkeeping.","Operational and economic consequences for owners/operators (asset retirement, verification of hours) despite simple wording.","Technical justification and alternative-compliance pathways are not described in the text, requiring consultation of external material for practical implementation."],"plain_english_summary":"What this directive does (mechanics)\n\n- The airworthiness directive applies to all Piper PA-28-235 aeroplanes (Applicability: All model PA-28-235).  \n- It requires that the wing be retired from service (Requirement: Retire the wing from service).  \n- The retirement must happen at or before 12,500 hours time in service (Compliance: At or before 12,500 hours time in service).\n\nWho this affects\n\n- Owners and operators of PA-28-235 aircraft: they must remove the affected wing from service once the aircraft (or that wing) reaches 12,500 hours time in service.  \n- Maintenance organisations and certificated engineers: they will be involved in determining when the retirement threshold has been reached and in accomplishing and recording the retirement action.  \n\nWhy it matters (stated and implied purpose, and how that interacts with costs and incentives)\n\n- The instrument is titled “Wing Structural Fatigue Life Limitation,” which implies its purpose is to limit service life to address wing structural fatigue. That purpose is not expanded in the text provided; the directive itself specifies only the mandatory retirement and the 12,500 hour threshold (see Applicability / Requirement / Compliance).  \n\n- Who pays: owners/operators bear the direct cost of retiring the wing. That may include the cost of replacing or repairing the aircraft, loss of remaining useful life of the wing as an asset, disposal costs, and any operational disruption while the aircraft is out of service. (Source: Requirement; Compliance.)  \n\n- Incentives and behaviour: the fixed hours threshold creates a clear incentive for operators to track time-in-service precisely. Operators may choose between (a) retiring the wing (and possibly the aircraft), (b) seeking approved modification or replacement solutions if available, or (c) withdrawing the aircraft from use earlier to avoid investment into an asset with a mandated finite life. The directive does not describe allowed alternatives or life-extension procedures. (Source: Requirement; Compliance.)  \n\n- Compliance burden and verification: the directive sets a hard numeric limit (12,500 hours) but does not specify in this text how retirement must be certified, who records the retirement, or what documentary proof is required. That omission means operators and maintainers must rely on applicable recordkeeping rules and regulatory practice to demonstrate compliance. (Source: Compliance.)  \n\n- Bureaucratic discretion and implementation risk: discretion appears limited as the directive prescribes a single retirement threshold; however the text does not specify administrative processes for approving alternatives, nor does it state enforcement procedures, so practical discretion will lie with the enforcing regulator and with approved maintenance/continuing airworthiness procedures outside this short text. (Source: entire directive text.)  \n\nMarket and operational effects (mechanisms, not judgments)\n\n- Asset life and resale: by capping wing service at 12,500 hours, the directive reduces the maximum legally usable life of that component, which will affect asset valuation and resale prospects for affected aircraft. (Source: Compliance.)  \n\n- Maintenance, aftermarket and replacement demand: compulsory retirement creates demand for replacement aircraft, replacement wings (if an approved replacement exists), or alternative services (salvage, part-out), though the directive does not describe permitted replacements or upgrades. (Source: Requirement; Compliance.)  \n\n- Competition and independent operators: independent maintenance organisations may be engaged to accomplish retirements or to offer compliant solutions; the directive itself does not restrict who may perform the work. (Source: Requirement.)\n\nTrade-offs, opportunity costs and unintended consequences (conditional on the directive’s implied safety purpose)\n\n- If the directive’s aim is to reduce risk from fatigue, the trade-off is transferring the economic cost of that risk-reduction onto aircraft owners and operators in the form of earlier component retirement.  \n- Opportunity costs include hours of operation foregone for the wing component and potential premature disposal of aircraft.  \n- Unintended operational responses could include accelerated retirement of entire aircraft, shifts to different aircraft types, or attempts to extend service through modifications—responses that depend on whether approved alternatives exist, which the text does not state. (Source: title; Requirement; Compliance.)\n\nWhat the text does not say (important implementation gaps)\n\n- The directive does not describe certification procedures for retirement, allowable replacement parts or modifications, enforcement details, or transitional provisions. It also does not give a technical explanation or empirical evidence in the text for choosing 12,500 hours. (Source: entire directive text.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This appears to be the original 1976 directive (indicated by '12/76' in the title). The scope remains precisely targeted: a specific aircraft model, a specific component (wings), and a specific flight hour limit. There is no evidence of scope creep — the directive does exactly what it was designed to do and nothing more."},"complexity_factors":["Extremely short document — only 4 substantive lines","No defined terms section","No cross-references to other legislation or regulations","Simple conditional logic: single applicability criterion (model PA-28-235) and single compliance threshold (12,500 hours)","No exceptions, exemptions, or nested conditions","Clear imperative language ('Retire the wing from service')","Minimal regulatory machinery — essentially a binary on/off safety command"],"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) under the Civil Aviation Regulations 1998.\n\n**What it does:** It orders owners and operators of specific Piper aircraft (the PA-28-235 model) to permanently ground and remove the aircraft's wings from service once they reach 12,500 hours of flight time.\n\n**Who it affects:** Anyone who owns, operates, or maintains Piper PA-28-235 aircraft in Australia.\n\n**Why it matters:** This is a hard \"life limit\" imposed for safety reasons. After 12,500 hours of use, the wings are considered structurally unsafe due to metal fatigue — the gradual weakening of materials from repeated stress cycles. Rather than requiring ongoing inspections, this directive mandates permanent retirement of the wing structure, effectively ending the aircraft's operational life unless the wings are replaced."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation","history":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation/history","analysis":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation/analysis","conflicts":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation/conflicts","importantCases":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation/important-cases","documents":"/api/acts/ad-pa-28-58-wing-structural-fatigue-life-limitation/documents"}}