{"id":"F2006B05460","name":"AD/PA-23/30 - Rudder Trim Tab Horn - Inspection","slug":"ad-pa-23-30-rudder-trim-tab-horn-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46223,"registerId":"commonwealth-F2006B05460-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-23/30 - Rudder Trim Tab Horn - 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-23 (Apache and Aztec) Series Aeroplanes\n\n \n\nAD/PA-23/30 Rudder Trim Tab Horn - Inspection 5/63\n\nApplicability: Models PA-23 and PA-23-160.\n\n \n\nRequirement: 1. Visually inspect, with at least a 10X magnifying glass, the rudder trim tab horn attach rivets for looseness or evidence of rivet working and the adjacent tab skin for cracks. If skin cracks, loose or working rivets are found, visually inspect the rudder trim tab support rib P/N 17468-17 for cracking; or\n\n \n\n2. FAA AD 63-7-3.\n\n \n\nCompliance:  Not later than 700 hours total time in service and thereafter at intervals not exceeding 100 hours time in service.\n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text sets a focused inspection requirement for rudder trim tab horn attach rivets, adjacent tab skin, and a conditional follow-up inspection of support rib P/N 17468-17 on specified PA-23 models, with a clear compliance interval and an alternative compliance route (FAA AD 63-7-3). The document itself does not indicate any expansion or narrowing of that scope relative to an earlier or different instrument; therefore no change in scope is evident from the supplied text."},"complexity_factors":["Narrow applicability to two specific aeroplane models (PA-23 and PA-23-160) (Applicability)","Prescriptive inspection method (visual inspection with at least a 10X magnifying glass) (Requirement 1)","Conditional follow-up inspection of a single part (rudder trim tab support rib P/N 17468-17) if defects are found (Requirement 1)","Alternative compliance option by following FAA AD 63-7-3 (Requirement 2)","Recurring, time-based compliance schedule (initial at 700 hours TIS; thereafter every 100 hours TIS) (Compliance)","Use of a specific part number increases technical specificity for follow-up work (Requirement 1)"],"plain_english_summary":"Requires recurring visual inspections (minimum 10X magnifier) of the rudder trim tab horn rivets and adjacent tab skin on Piper PA‑23 and PA‑23‑160 aircraft — initial by 700 hours TIS, then every 100 hours. If looseness or cracking is found, inspect support rib P/N 17468‑17. Operators/maintenance organisations pay for inspections and repairs and may instead comply with FAA AD 63‑7‑3. This targets a localized fatigue/corrosion risk and creates recurring labour and potential downtime costs."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a vintage AD (originally issued 1963, indicated by '5/63' and 'AD 63-7-3' reference) that has remained focused on its original narrow purpose: inspecting a specific fatigue-prone component on two specific aircraft models. No scope creep detected."},"complexity_factors":["Single, specific mechanical component addressed (rudder trim tab horn)","Only 2 defined models affected (PA-23 and PA-23-160)","Straightforward inspection procedure with clear alternative compliance path (FAA AD 63-7-3)","Simple time-based compliance schedule (700 hours initial, 100 hours recurring)","No nested exceptions, conditional logic, or cross-references to other legislation beyond optional FAA reference","Total length: approximately 150 words"],"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 compulsory recall notice for aircraft, but instead of returning the product, owners must perform specific inspections or repairs.\n\n**What it does:** This AD targets a specific mechanical problem on Piper PA-23 Apache and Aztec aeroplanes (twin-engine aircraft popular in the 1950s-60s). The concern is the **rudder trim tab horn** — a small control surface on the tail that helps keep the plane flying straight without constant foot pressure on the pedals.\n\nThe directive requires owners/operators to:\n- **Visually inspect** the rivets holding the trim tab horn using at least 10x magnification (basically, a jeweller's loupe or good magnifying glass)\n- Look for loose rivets, rivets that have shifted ('working'), or cracks in the surrounding metal skin\n- If any damage is found, also check an internal support rib (part number 17468-17) for cracking\n- Alternatively, comply with an equivalent American FAA directive (AD 63-7-3)\n\n**Who it affects:** Owners and operators of Piper PA-23 and PA-23-160 model aircraft.\n\n**When to comply:** \n- First inspection required by 700 total flight hours on the aircraft\n- Repeat inspections every 100 flight hours thereafter\n\n**Why it matters:** A failed rudder trim tab horn could cause loss of directional control or structural failure in flight. This AD prevents catastrophic accidents by catching fatigue cracks early."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection","history":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection/history","analysis":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection/analysis","conflicts":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection/conflicts","importantCases":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection/important-cases","documents":"/api/acts/ad-pa-23-30-rudder-trim-tab-horn-inspection/documents"}}