{"id":"F2006B05770","name":"AD/PA-31/66 - Nose Landing Gear Wheel - Inspection","slug":"ad-pa-31-66-nose-landing-gear-wheel-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135629,"registerId":"commonwealth-F2006B05770-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/66 - Nose Landing Gear Wheel - Inspection","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-31 Series Aeroplanes\n\n \n\nAD/PA-31/66 Nose Landing Gear Wheel - Inspection 5/78\n\nApplicability: All model PA-31T with S/Nos. 31-7620012 and up except those fitted with NLG wheel assembly Piper P/N 551-758, BF Goodrich P/N 3-1331.\n\n \n\nRequirement: Visually inspect the nosewheel Piper P/N 551/778, Cleveland P/N 40-120A in the cup and flange areas for cracks.\n\n \n\nNote: Cracked wheels must be replaced before further flight. If replaced by wheel of same P/N wheel must be inspected before each flight. Initial and recurring inspections may be performed and certified by the pilot in command.\n\n \n\nCompliance: Before further flight.\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 text does not indicate any amendment or narrowing/expansion relative to an earlier instrument. It sets a standalone inspection requirement that applies to the specified aircraft and wheel part numbers as written (Applicability; Requirement; Note; Compliance)."},"complexity_factors":["Narrow applicability: only PA-31T with specified S/N range, except where alternate wheel assemblies are fitted (Applicability).","Single required action: a visual inspection of a specific wheel area for cracks (Requirement).","Immediate compliance timing: action required \"before further flight\" creates operational urgency (Compliance).","Follow-up rule: cracked wheels must be replaced and, if replaced by same part number, require per‑flight inspections thereafter (Note).","Certification allowance: pilot in command may perform and certify inspections, shifting compliance pathway away from maintenance organisations (Note).","Technical identification: reliance on manufacturer part numbers for both applicability and requirement creates precision but requires accurate parts knowledge (Applicability; Requirement)."],"plain_english_summary":"### What this directive does, in plain English\n\nThis airworthiness directive orders a one-time visual inspection of a specific nosewheel type on a narrow set of Piper PA-31T aeroplanes. It applies only to PA-31T aircraft with serial numbers 31-7620012 and up, except those that already have a different approved nose landing gear (NLG) wheel assembly (Piper P/N 551-758 or BF Goodrich P/N 3-1331) (Applicability).\n\nMechanically, the directive requires a visual check of the nosewheel (Piper P/N 551/778 or Cleveland P/N 40-120A) in the cup and flange areas for any cracks (Requirement). If the wheel is found to be cracked, it must be replaced before the aircraft flies again (Note). If a cracked wheel is replaced with the same part number, that wheel must then be inspected before each flight going forward (Note). The document allows the initial and any recurring inspections to be carried out and certified by the pilot in command rather than by a licensed maintenance organisation (Note). The stated timing for compliance is \"before further flight\" (Compliance).\n\nWho pays and who decides\n\n- Who pays: Aircraft owners or operators bear the direct costs — the time to perform inspections and the cost of any replacement wheels (Note; Requirement). Replacement wheels and installation (if performed by maintenance staff) are an explicit cost exposure for owners/operators. Ongoing per‑flight inspections (if a replacement of the same part number is fitted) increase operating time cost (Note).\n- Who decides and certifies: The pilot in command may perform and certify the initial and recurring inspections, shifting some decision and certification responsibility onto the flight crew rather than requiring a maintenance organisation (Note).\n\nBehaviours and incentives the rule creates\n\n- Operators of affected PA-31T aircraft must inspect the specified nosewheel before next flight and replace cracked wheels before flying (Requirement; Note; Compliance).\n- If an operator replaces an inspected wheel with another wheel of the same part number, the operator is required to inspect that wheel before every flight thereafter; this creates an incentive either to fit the excepted wheel assemblies (551-758 or 3-1331) to avoid recurring inspections, or to accept the ongoing pre‑flight inspection cost (Note).\n- Allowing the pilot in command to perform and certify inspections lowers compliance costs by reducing the need for formal maintenance resources, but shifts operational responsibility and potential liability onto pilots (Note).\n\nCosts, trade-offs and implementation considerations\n\n- Direct costs: Time taken to visually inspect the wheel and cost of replacement wheels when cracks are found (Requirement; Note).\n- Recurring costs: If a wheel is replaced by the same part number, there is an ongoing per‑flight inspection requirement which adds operating time and audit/recording burden (Note).\n- Compliance timing: The directive’s \"before further flight\" requirement forces immediate action; operators cannot defer the inspection to routine maintenance windows (Compliance).\n- Enforcement and discretion: The directive is prescriptive about the action required (inspect; replace cracked wheels), but it leaves methods and record‑keeping practices unspecified. Certification may be performed by the pilot in command, which reduces regulatory paperwork for maintenance providers but concentrates judgement and certification discretion in pilots (Note).\n\nScope, substitution and market effects\n\n- Narrow scope: The rule targets a narrowly defined group of aircraft and two specific wheel part numbers, so the affected population is small (Applicability).\n- Substitution effect: The explicit exception for aircraft fitted with alternate NLG wheel assemblies (551-758 or 3-1331) creates a clear substitution path: installing those wheel assemblies removes an aircraft from this inspection requirement (Applicability). That substitution imposes an upfront retrofit cost but may reduce recurring inspection costs.\n\nSummary of operational instructions (source sections)\n\n- Which aircraft: PA-31T S/N 31-7620012 and up, except those with NLG wheel assembly Piper P/N 551-758 or BF Goodrich P/N 3-1331 (Applicability).\n- What to do: Visually inspect Piper P/N 551/778 or Cleveland P/N 40-120A nosewheel in cup and flange areas for cracks (Requirement).\n- If cracked: Replace wheel before further flight (Note).\n- If replaced by same P/N: Inspect before each flight thereafter (Note).\n- Who may inspect/certify: Pilot in command may perform and certify initial and recurring inspections (Note).\n- When: Before further flight (Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of ensuring nose wheel integrity."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 4 defined part numbers referenced","Single straightforward requirement with one clear exception","No nested conditional logic or cross-references to other legislation","Simple compliance structure: one-time inspection with possible recurring requirement only if specific replacement part used","Plain language instructions suitable for pilot self-certification"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Piper PA-31T aircraft to inspect their nose landing gear (front wheel) for dangerous cracks.\n\n**Who it affects:**\n- Owners and pilots of Piper PA-31T aircraft with serial numbers 31-7620012 and higher\n- **Exception:** Aircraft already fitted with a specific replacement wheel assembly (Piper P/N 551-758 or BF Goodrich P/N 3-1331) are exempt\n\n**What must be done:**\n- **Visual inspection** of the nose wheel (specific part numbers: Piper 551/778 or Cleveland 40-120A) in two critical areas — the \"cup\" and \"flange\" — looking for cracks\n- **When:** Before the aircraft flies again (immediate compliance)\n- **Who can do it:** The pilot in command (the person flying the plane) can perform and certify both the initial inspection and ongoing recurring inspections\n\n**Critical safety rule:**\n- If cracks are found, the wheel **must be replaced** before any further flight\n- If replaced with the same part number, that new wheel must be inspected **before every single flight** going forward\n\n**Why it matters:** Cracked landing gear wheels can fail catastrophically during takeoff or landing, potentially causing loss of control, runway accidents, or fatalities. This directive prevents that by catching defects early."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection","history":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection/history","analysis":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection/analysis","conflicts":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection/conflicts","importantCases":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection/important-cases","documents":"/api/acts/ad-pa-31-66-nose-landing-gear-wheel-inspection/documents"}}