{"id":"F2008L01856","name":"AD/PA-23/20 - Stabilator Tab Horn - Modification - CANCELLED","slug":"ad-pa-23-20-stabilator-tab-horn-modification-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74057,"registerId":"commonwealth-F2008L01856-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Piper PA-23 (Apache and Aztec) Series Ae","sectionType":"division","heading":"Piper PA-23 (Apache and Aztec) Series Aeroplanes","content":"### Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n| AD/PA-23/20 | Stabilator Tab Horn - Modification | 7/2008 |\n| ----------- | ---------------------------------- | ------ |\n\n| Requirement: | CANCELLED.                                                                                                                                                                                                      |\n| ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 3 July 2008.                                                                                                                                                                            |\n| Background:  | This Directive was based on Piper Service Bulletin No. 189 calling for once-only replacement of a component in 1960. As all affected aircraft would have been modified long ago, this AD is no longer required. |\n\n![](image.001.png)\n\nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n7 May 2008","sortOrder":0},{"sectionNumber":"AD/PA-23/20","sectionType":"part","heading":"AD/PA-23/20","content":"## AD/PA-23/20","sortOrder":1},{"sectionNumber":"Stabilator Tab Horn - Modification","sectionType":"part","heading":"Stabilator Tab Horn - Modification","content":"## Stabilator Tab Horn - Modification","sortOrder":2},{"sectionNumber":"7/2008","sectionType":"part","heading":"7/2008","content":"## 7/2008","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1688},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"The instrument performs exactly the limited function its title suggests: cancelling a specific obsolete Airworthiness Directive. There is no expansion of scope beyond removing the previous requirement."},"complexity_factors":["Single operative provision (cancellation only)","No defined terms or interpretation section","No conditional logic or exceptions","No cross-references to other legislation","Extremely short (substantive content less than 100 words)"],"plain_english_summary":"**What this does:** This document officially scraps an old aircraft maintenance rule (called an Airworthiness Directive or AD) that applied to Piper PA-23 Apache and Aztec planes.\n\n**Who it affects:** Owners and operators of these specific vintage aircraft models.\n\n**The backstory:** The original rule required a one-time replacement of a part called the \"stabilator tab horn\" (a component that helps control the aircraft's tail). This requirement came from a manufacturer bulletin issued way back in 1960.\n\n**Why it matters:** Since this was a one-off modification required nearly 50 years ago, aviation authorities determined that every affected aircraft would have already completed the fix by now. Keeping the rule on the books served no purpose, so this document formally cancels it as of **3 July 2008**, removing an unnecessary compliance burden for aircraft owners."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled","history":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled/history","analysis":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled/analysis","conflicts":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled/conflicts","importantCases":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled/important-cases","documents":"/api/acts/ad-pa-23-20-stabilator-tab-horn-modification-cancelled/documents"}}