{"id":"F2006B05669","name":"AD/PA-30/28 - Fin Forward Spar Attachment - Inspection","slug":"ad-pa-30-28-fin-forward-spar-attachment-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135398,"registerId":"commonwealth-F2006B05669-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-30/28 - Fin Forward Spar Attachment - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPiper PA-30 & 39 (Twin Comanche) Series Aeroplanes\n\nAD/PA-30/28 Fin Forward Spar Attachment \\- Inspection 9/76\n\nApplicability: All models PA-30 and PA-39 with S/Nos. 30-1 to 30-2000 and 39-1 to 39-155.\n\nRequirement: Visually inspect, with the aid of at least a 5X glass, the fin forward spar to fuselage attachment for cracks in the bend relief cutout radius of channel P/N 22903-00.\n\nNote 1: The part number quoted may not appear in the Parts Catalogue as it is a component of the fin front spar which is listed as a complete assembly under a separate part number.\n\nNote 2: Piper SL No. 777 provides instructions for modifying the Fin Assembly to gain Visual access to the channel relief holes.\n\nNote 3: This inspection is the subject of FAA AD 76-18-05.\n\nCompliance: Within 50 hours time in service after 22 September 1976 and there- after at intervals not exceeding 100 hours time in service.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Based on the supplied text, the instrument sets out a narrowly focused inspection requirement for the fin forward spar attachment on specified PA-30 and PA-39 serial numbers. The text prescribes what to inspect, the inspection method, and the compliance intervals, and it cross-references a service letter for access and an FAA AD for equivalence. The document does not indicate any expansion or reduction of that stated inspection scope relative to its own terms."},"complexity_factors":["Narrow applicability limited to specific serial-number ranges (PA-30 S/N 30-1 to 30-2000; PA-39 S/N 39-1 to 39-155) (Applicability).","Single, well-defined inspection task with a prescribed tool requirement (visual inspection using at least a 5X magnifying glass) (Requirement).","Fixed compliance timing (first inspection within 50 hours TIS after 22 Sep 1976; then every 100 hours TIS) that imposes operational scheduling constraints (Compliance).","Reference to a part number that may not be separately listed in parts catalogue, requiring cross-referencing to the assembly (Note 1).","Reference to an external service letter (Piper SL No. 777) for a modification to gain access, introducing an additional procedural step and potential extra work/cost (Note 2).","The directive specifies an inspection but does not state remedial or corrective actions within the supplied text, leaving follow-up actions unspecified (Requirement).","Cross-jurisdictional reference to FAA AD 76-18-05 (Note 3) which may require checking another instrument for related requirements."],"plain_english_summary":"### What this instrument does\n\nThis airworthiness directive requires regular visual inspections of a specific attachment on Piper PA-30 and PA-39 (Twin Comanche) aeroplanes. It targets the fin forward spar to fuselage attachment area and instructs operators to look for cracks in the bend relief cutout radius of channel P/N 22903-00. (See: \"Applicability\" and \"Requirement\".)\n\n### Who it affects\n\n- Owners and operators of all PA-30 and PA-39 aircraft with serial numbers 30-1 to 30-2000 and 39-1 to 39-155. (See: \"Applicability\".)\n\n### What owners/operators must do\n\n- Perform a close visual inspection, using at least a 5X magnifying glass, specifically on the bend relief cutout radius of channel P/N 22903-00 to detect cracks. (See: \"Requirement\".)\n- The first inspection must be done within 50 hours time in service after 22 September 1976, and thereafter at intervals not exceeding 100 hours time in service. (See: \"Compliance\".)\n- Note that the quoted part number may not appear separately in the Parts Catalogue because it is a component of the fin front spar assembly. (See: \"Note 1\".)\n- Piper Service Letter No. 777 gives instructions for modifying the fin assembly to gain visual access to the channel relief holes; following that service letter may be necessary to carry out the inspection. (See: \"Note 2\".)\n- This directive corresponds to FAA AD 76-18-05. (See: \"Note 3\".)\n\n### Who pays and what are the direct burdens\n\n- Aircraft owners/operators bear the direct cost and operational burden of performing the inspections and any modifications needed to obtain visual access (for example, following Piper SL No. 777). The AD prescribes the inspection method and the timing, so operators must schedule inspections within the stated time-in-service windows. (See: \"Requirement\", \"Note 2\", \"Compliance\".)\n\n### Incentives and compliance dynamics\n\n- The directive creates an explicit compliance obligation with fixed time windows (50 hours then every 100 hours TIS). That creates an operational scheduling cost: inspections must be done within those flight-hour windows, which affects aircraft availability. (See: \"Compliance\".)\n- The AD specifies inspection technique (visual with at least 5X glass), constraining how operators can demonstrate compliance. (See: \"Requirement\".)\n- Because the part number may not be listed separately in the Parts Catalogue, identifying the correct component could require cross-referencing assembly records or dealer support, adding administrative and diagnostic effort. (See: \"Note 1\".)\n\n### Implementation risk and practical trade-offs\n\n- The AD does not specify remedial actions or follow-up steps in the supplied text; it only prescribes inspecting for cracks. The absence of specified corrective measures in the text means operators must rely on other maintenance directions or regulatory guidance if a crack is found. (See: \"Requirement\".)\n- Gaining visual access may require modification procedures described in Piper SL No. 777; that introduces an additional, discrete maintenance task before inspections can be performed. (See: \"Note 2\".)\n\n### Cross-references and administrative notes\n\n- The AD identifies a specific component by part number but warns it may be catalogued only as part of the complete fin front spar assembly. (See: \"Note 1\".)\n- The same inspection requirement is the subject of FAA AD 76-18-05, which the directive cites as equivalent action. (See: \"Note 3\".)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural defect in specific aircraft models. It has not expanded beyond its original purpose of mandating recurring inspections for crack detection in the fin spar attachment."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined elements: specific aircraft models and serial number ranges","Single, clear compliance requirement with straightforward timing (50 hours initially, then 100-hour intervals)","No cross-references to other legislation or regulations beyond a citation to the enabling Civil Aviation Regulations 1998 and a reference to the equivalent FAA directive","No conditional logic or exceptions — applies to all listed aircraft without exemptions","Simple, technical aviation terminology that is standard for maintenance personnel"],"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). Think of it as a recall notice for aircraft, but legally binding.\n\n**What it does:** It requires owners and operators of specific Piper twin-engine aeroplanes (the PA-30 and PA-39 \"Twin Comanche\" models) to inspect a critical structural part — the **fin forward spar attachment** — for cracks.\n\n**Who it affects:** Anyone who owns or operates:\n- Piper PA-30 aircraft with serial numbers 30-1 through 30-2000\n- Piper PA-39 aircraft with serial numbers 39-1 through 39-155\n\n**The specific problem:** The channel (a metal bracket, part number 22903-00) that connects the tail fin to the fuselage can develop cracks in a specific curved area (the \"bend relief cutout radius\"). If this part fails, the tail could separate from the aircraft.\n\n**What must be done:**\n- **First inspection:** Within 50 hours of flying time after 22 September 1976\n- **Repeat inspections:** Every 100 hours of flying time thereafter\n- **How:** Visual inspection using at least a 5x magnifying glass\n\n**Why it matters:** This addresses a known structural weakness that could lead to catastrophic failure of the aircraft's tail section. The directive references an equivalent US Federal Aviation Administration (FAA) order, showing this was a recognised international safety issue.\n\n**Helpful notes included:**\n- The part number might not appear in standard parts manuals because it's a sub-component\n- There's a service letter (SL No. 777) explaining how to modify the fin to make inspection easier"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection","history":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection/history","analysis":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection/analysis","conflicts":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection/conflicts","importantCases":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection/important-cases","documents":"/api/acts/ad-pa-30-28-fin-forward-spar-attachment-inspection/documents"}}