{"id":"F2007L04016","name":"AD/ENST 28/29 - Rotor Head Hub - CANCELLED","slug":"ad-enst-28-29-rotor-head-hub-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":160807,"registerId":"commonwealth-F2007L04016-current","compilationNumber":null,"startDate":"2026-04-04","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Enstrom F-28 Series Helicopters","sectionType":"division","heading":"Enstrom F-28 Series Helicopters","content":"### Enstrom F-28 Series Helicopters\n\n| AD/ENST 28/29 | Rotor Head Hub | 11/2007 |\n| ------------- | -------------- | ------- |\n\n| Requirement: | CANCELLED.                                                                                                                                                                                                |\n| ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 25 October 2007.                                                                                                                                                                  |\n| Background:  | Enstrom have reported no cracked hub plates since the release of the SDB. The SDB was cancelled on 29 March 2007. All periodic inspections of the main rotor hub are contained in the Maintenance Manual. |\n\n![](image.001.png)\n\nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n14 September 2007","sortOrder":0},{"sectionNumber":"AD/ENST 28/29","sectionType":"part","heading":"AD/ENST 28/29","content":"## AD/ENST 28/29","sortOrder":1},{"sectionNumber":"Rotor Head Hub","sectionType":"part","heading":"Rotor Head Hub","content":"## Rotor Head Hub","sortOrder":2},{"sectionNumber":"11/2007","sectionType":"part","heading":"11/2007","content":"## 11/2007","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":3355},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":true,"description":"The instrument has transitioned from imposing specific, mandatory inspection obligations on helicopter operators to being completely inoperative. It no longer regulates any conduct."},"complexity_factors":["Single operative provision (cancellation)","No defined terms or interpretation section","No conditional logic, exceptions, or penalties","Minimal cross-referencing (background only)"],"plain_english_summary":"This **Airworthiness Directive (AD)**—a type of safety regulation issued by the Civil Aviation Safety Authority (CASA)—cancels previous mandatory inspection rules for Enstrom F-28 helicopter rotor head hubs.\n\n**Who it affects:** Owners, operators, and maintenance crews of Enstrom F-28 series helicopters.\n\n**What it does:** It removes a standalone legal requirement to inspect for cracked hub plates under a specific Service Difficulty Bulletin (SDB). Those safety checks are now handled through the standard aircraft Maintenance Manual instead.\n\n**Why it matters:** It streamlines compliance for operators. CASA determined the special directive was no longer necessary because the manufacturer reported no new cracks since the bulletin was released, and the routine maintenance rules now adequately cover the risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled","history":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled/history","analysis":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled/analysis","conflicts":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled/conflicts","importantCases":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled/important-cases","documents":"/api/acts/ad-enst-28-29-rotor-head-hub-cancelled/documents"}}