{"id":"F2009L00141","name":"AD/PA-30/23 Amdt 3 - Stabilator Attachment Bolts - Inspection","slug":"ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76576,"registerId":"commonwealth-F2009L00141-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Piper PA-30 & 39 (Twin Comanche) Series ","sectionType":"division","heading":"Piper PA-30 & 39 (Twin Comanche) Series Aeroplanes","content":"### Piper PA-30 & 39 (Twin Comanche) Series Aeroplanes\n\n| AD/PA-30/23 Amdt 3 | Stabilator Attachment Bolts - Inspection | 2/2009 |\n| ------------------ | ---------------------------------------- | ------ |\n\n| Applicability: | All model Piper PA-30 with serial numbers from 30-1 to 30-2000, and all model Piper PA-39 with serial numbers from 39-1 to 39-155, if the four stabilator attachment bolts are not made of corrosion-resistant steel.                                                                                                                                                                                                                                                                                                                                                                       |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Remove the four stabilator attachment bolts and inspect for corrosion in accordance with:(a) Piper PA-30 aircraft - Piper SL No. 667A.(b) Piper PA-39 aircraft - Piper SL No. 772.If corrosion is found, before further flight replace the bolt, nut and washer with unused parts of the same part numbers or equivalent. Alternatively, the bolts can be replaced by equivalent corrosion-resistant AN bolts.Note 1: Parts numbered 502329 and 502342 are corrosion-resistant bolts.Note 2: FAA AD 74-13-03 (amdt 39-2588) refers.                                                         |\n| Compliance:    | At intervals not exceeding three years or five hundred hours time in service, whichever occurs first. Alternatively, the bolts can be replaced by equivalent corrosion-resistant AN bolts.Note 3: Compliance with this AD at amendment 2 constitutes compliance with this amendment.                                                                                                                                                                                                                                                                                                        |\n|                | This Amendment becomes effective on 12 February 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| Background:    | The original issue of this AD in January 1974 applied to Piper PA-30 only, and specified replacement of stabilator attachment bolts within 100 hours after31 January 1974, based on Piper SL No. 667.Amendment 1 in March 1974 specified inspection at 3 monthly intervals as an alternative to replacement, due to difficulties with supply of suitable corrosion-resistant bolts. In March 1974 Piper issued SL No. 667A to authorise, as an alternative to corrosion-resistant bolts, new steel alloy bolts with repetitive inspections at intervals not to exceed 500 hours in service. |\n\n|     | In June 1974 the FAA issued AD 74-13-03 (amdt 39-1872) specifying inspection at intervals not to exceed 3 years or 500 hours, whichever occurred first, as an alternative to replacement. Amdt 39-1872 nominated Piper SL No. 667A.Amendment 2 in January 1975 extended applicability to include Piper PA-39, based on defects reported in Australia.In February 1976 Piper issued SL No. 772 applicable to Piper PA-39. In April 1976 the FAA re-issued AD 74-13-03 at amdt 39-2588 to extend applicability to include Piper PA-39.Amendment 3 is raised to align the inspection interval with FAA AD 74-13-03; to define serial number applicability; to identify the FAA AD on which AD/PA-30/23 is now based; and to add Piper SL No. 667A and SL No. 772 as the instructions for inspecting steel alloy bolts. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n12 December 2008","sortOrder":0},{"sectionNumber":"AD/PA-30/23 Amdt 3","sectionType":"part","heading":"AD/PA-30/23 Amdt 3","content":"## AD/PA-30/23 Amdt 3","sortOrder":1},{"sectionNumber":"Stabilator Attachment Bolts - Inspection","sectionType":"part","heading":"Stabilator Attachment Bolts - Inspection","content":"## Stabilator Attachment Bolts - Inspection","sortOrder":2},{"sectionNumber":"2/2009","sectionType":"part","heading":"2/2009","content":"## 2/2009","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. The instrument as issued in 1974 required replacement of stabilator attachment bolts within a short time frame. Over successive amendments it expanded in form and scope: it introduced repetitive inspections as an acceptable alternative to immediate replacement (initially due to bolt supply problems), extended applicability to include PA-39 aircraft, and later clarified serial-number applicability and inspection intervals to align with the FAA AD. Amendment 3 does not introduce a new safety subject but refines and narrows applicability (by defining serial number ranges), aligns inspection intervals with the FAA, and specifies the Piper service letters as the inspection instructions. In aggregate these changes shift the remedy from one‑off mandatory replacement towards a mixed regime of recurring inspections or optional one‑off replacement with corrosion‑resistant parts, and extend the set of affected aircraft (PA-39)."},"complexity_factors":["Short, focused document with a single technical requirement (inspection/replacement).","Two alternative compliance methods (repetitive inspection OR replacement with corrosion‑resistant bolts).","Cross-references to external documents: Piper Service Letters SL No. 667A and SL No. 772 for inspection procedures.","Cross-reference to FAA AD 74-13-03 and historical amendment citations (background history).","Applicability limited by serial number ranges and conditional on bolt material (non‑corrosion‑resistant).","Notes identifying specific part numbers (502329 and 502342) as corrosion‑resistant alternatives."],"plain_english_summary":"**What this AD does (in plain English)**\n\n- This airworthiness directive (AD) requires owners/operators of certain Piper PA-30 and PA-39 Twin Comanche aeroplanes to remove and inspect the four stabilator attachment bolts for corrosion, and to replace any corroded parts before further flight. It applies only where those bolts are not already made of corrosion-resistant steel (Applicability).\n\n- The inspection must follow the procedures in the Piper service letters specified for each model (Piper SL No. 667A for PA-30; Piper SL No. 772 for PA-39) (Requirement).\n\n- If corrosion is found the AD requires replacing the bolt, nut and washer with unused parts of the same part numbers or equivalents, or alternatively replacing the bolts with equivalent corrosion‑resistant AN bolts. The AD identifies two part numbers (502329 and 502342) as corrosion‑resistant options (Requirement, Note 1).\n\n- Inspections must be repeated at intervals not exceeding three years or 500 hours time in service, whichever happens first. As an alternative to the recurring inspections, the bolts may be replaced with corrosion‑resistant AN bolts (Compliance).\n\n- The AD applies to all Piper PA-30 with serial numbers 30-1 through 30-2000, and all Piper PA-39 with serial numbers 39-1 through 39-155, but only where the four stabilator attachment bolts are not corrosion‑resistant (Applicability).\n\n**Who is affected**\n\n- Aircraft owners and operators of the specified PA-30 and PA-39 serial-numbered aeroplanes that have non‑corrosion‑resistant stabilator attachment bolts.\n- Maintenance organisations and licensed mechanics who must perform the inspections and replacements.\n\n**Why it matters (official rationale and what that implies practically)**n\n- Officially, the AD aims to manage the safety risk from corroded stabilator attachment bolts. The background explains it has been updated over time to align inspection intervals with a corresponding FAA AD, to define serial-number applicability, and to point to the relevant Piper service letters as the inspection instructions (Background).\n\n- Practically, the AD creates a recurring maintenance obligation (inspection every 3 years or 500 hours) unless the owner replaces the bolts with corrosion‑resistant ones. Replacing with corrosion‑resistant bolts is a one‑off action that removes the need for the recurring inspection requirement.\n\n**Costs, incentives and trade‑offs**\n\n- Who pays: aircraft owners/operators pay for inspection labour and any replacements (Requirement; Compliance). If corrosion is found they must buy and fit new bolts, nuts and washers (or corrosion‑resistant bolts). If they choose to replace with corrosion‑resistant bolts up front they pay that replacement cost to avoid ongoing inspections.\n\n- Incentives: the AD creates a clear trade‑off: pay the one‑off cost to fit corrosion‑resistant bolts to avoid recurring inspections, or accept the recurring inspection cost and potential replacement when corrosion is found.\n\n- Opportunity cost and implementation risk: recurring inspections create a continuing administrative and maintenance load (scheduling, record keeping, downtime). Inspections can miss early microscopic corrosion, so there is a residual risk that intermittent inspections may not catch very fast‑progressing corrosion between checks; replacing with corrosion‑resistant bolts reduces that risk.\n\n- Effects on operators and independent maintenance businesses: small operators face periodic costs and scheduling constraints; maintenance businesses receive inspection and replacement work. Parts supply constraints were historically relevant (Background notes supply difficulties in 1974), so availability of approved corrosion‑resistant bolts affects how readily operators can choose the replacement option.\n\n**Mechanics of compliance (practical steps)**\n\n1. Determine if your aircraft serial number is within the specified ranges and whether your stabilator bolts are non‑corrosion‑resistant (Applicability).\n2. If affected, remove the four stabilator attachment bolts and inspect them following the relevant Piper service letter for your model (Requirement).\n3. If corrosion is found, replace the bolt, nut and washer with unused parts of the same part numbers or equivalent, or use corrosion‑resistant AN bolts (Requirement).\n4. Repeat inspections at intervals not exceeding 3 years or 500 hours time in service (Compliance), unless you have fitted corrosion‑resistant bolts.\n\n**References in the AD that operators must follow**\n\n- Piper Service Letter No. 667A (PA-30) and No. 772 (PA-39) for inspection procedures (Requirement).\n- FAA AD 74-13-03 (amendment references) is identified as the FAA action on which this AD is based (Note/Background).\n\n**Practical implications to watch for**\n\n- Keep maintenance records to demonstrate compliance with the specified interval.\n- Confirm part numbers and equivalence before fitting substituted parts (Requirement, Note 1).\n- If you install corrosion‑resistant bolts, document that they are the specified part numbers or acceptable equivalents to avoid future inspection requirements.\n\n(Source sections referenced throughout: Applicability; Requirement; Compliance; Notes; Background.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original 1974 AD applied only to PA-30 aircraft and mandated bolt replacement within 100 hours. Through three amendments, the scope expanded significantly: (1) inspection became an alternative to replacement due to parts availability issues; (2) PA-39 aircraft were added in 1975 based on Australian defect reports; (3) this 2009 amendment adds serial number specificity, aligns with FAA inspection intervals, and incorporates two different service documents. The AD has evolved from a simple replacement mandate to a complex, repetitive inspection regime with multiple compliance paths."},"complexity_factors":["Multiple amendment history requiring cross-referencing (original 1974, amendments 1-3, plus FAA AD 74-13-03 at amendments 39-1872 and 39-2588)","Dual applicability tracks requiring different service documents (Piper SL 667A for PA-30 vs SL 772 for PA-39)","Conditional logic: applies only if bolts are NOT corrosion-resistant steel; compliance alternative exists (corrosion-resistant AN bolts)","Cross-references to external documents: two Piper Service Letters and one FAA AD","Serial number ranges must be checked to determine applicability","Note 3 creates a compliance equivalence rule (amendment 2 work satisfies amendment 3)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of affected Piper PA‑30 and PA‑39 twins that still have original, non‑corrosion‑resistant stabilator attachment bolts to perform repetitive removal and inspection of those four bolts every 3 years or 500 flight hours, replacing any corroded parts before flight. Replacing the bolts with corrosion‑resistant AN bolts terminates the inspections.\n\nIt addresses risk of stabilator failure from bolt corrosion and aligns Australian requirements with the FAA."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection","history":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection/history","analysis":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection/analysis","conflicts":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection/conflicts","importantCases":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection/important-cases","documents":"/api/acts/ad-pa-30-23-amdt-3-stabilator-attachment-bolts-inspection/documents"}}