{"id":"F2006B11416","name":"AD/OPTICA/4 - Fan Shaft Extension","slug":"ad-optica-4-fan-shaft-extension","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57328,"registerId":"commonwealth-F2006B11416-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/OPTICA/4 - Fan Shaft Extension","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)  FLS Aerospace OA7 Optica Series Aeroplanes\n\n \n\nAD/OPTICA/4 Fan Shaft Extension 1/95\n\nApplicability: All model OA7 Optica aircraft up to and including aircraft S/N 22 fitted with Hoffmann fan and fan shaft extension.\n\n \n\nRequirement: Action in accordance with FLS Aerospace LOVAUX Mandatory SB No B2/MSB/006 Issue 1.\n\n \n\nNote: UK CAA AD 010-08-94 refers.\n\n \n\nCompliance: As specified in the Requirement Document with a revised effective date of 5 January 1995.\n\n \n\nBackground: The manufacturer has advised that due to an error in the manufacturing process, the depth of the four counter bores may have exceeded limits and this could result in reduced fan to engine attachment integrity.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope remains targeted to the originally identified set of aircraft and equipment: OA7 Optica aeroplanes up to and including serial number 22 fitted with a Hoffmann fan and fan shaft extension. It prescribes compliance with the manufacturer's Mandatory Service Bulletin and sets a revised effective date (5 January 1995). There is no text in the instrument extending or narrowing the class of affected aircraft beyond that applicability statement. (Applicability; Requirement; Compliance.)"},"complexity_factors":["Narrow technical applicability (specific model, serial numbers and fitted equipment) (Applicability).","Mandates compliance by reference to an external technical document (FLS Aerospace Mandatory SB No B2/MSB/006 Issue 1) rather than setting technical steps in the AD itself (Requirement).","Legal force combined with operational dependence on maintenance resources, parts and downtime (Requirement; Compliance).","Cross‑reference to an overseas regulator’s AD (UK CAA AD 010-08-94), introducing potential for related but separate guidance (Note).","Fixed effective (compliance) date creating a timing constraint on operators (Compliance)."],"plain_english_summary":"This AD requires owners/operators of OA7 Optica aeroplanes up to S/N 22 fitted with a Hoffmann fan and fan‑shaft extension to carry out the actions in FLS Aerospace Mandatory SB B2/MSB/006 Issue 1. It addresses a manufacturer‑reported counter‑bore manufacturing error that may reduce fan‑to‑engine attachment integrity; compliance is required by 5 January 1995."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in a specific aircraft component. It has not expanded beyond its original purpose of mandating corrective action for the counter bore depth issue."},"complexity_factors":["Single, specific applicability criterion (aircraft model and serial number range)","Single mandatory action referencing an external technical document (service bulletin)","No defined terms section","No conditional logic or nested exceptions","Minimal cross-referencing (one UK CAA AD mentioned in a note only)","Extremely short document (approximately 150 words of substantive content)","Clear, unambiguous compliance deadline"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) requiring specific aircraft owners to fix a manufacturing defect.\n\n**Who it affects:** Owners and operators of **FLS Aerospace OA7 Optica series aeroplanes** — specifically all models up to and including serial number 22 that have a Hoffmann fan and fan shaft extension installed. These are small, observation-type aircraft with a distinctive bubble canopy.\n\n**What the problem is:** The manufacturer discovered that during production, the **counter bores** (precision-drilled holes that allow bolt heads to sit flush) on the fan shaft extension were drilled too deep. This manufacturing error weakens the connection between the fan and the engine — potentially causing the fan to detach in flight, which would be catastrophic.\n\n**What must be done:** Operators must follow the manufacturer's mandatory service bulletin (**FLS Aerospace LOVAUX Mandatory SB No B2/MSB/006 Issue 1**) to inspect and/or repair the affected parts. The UK aviation regulator issued a similar directive (UK CAA AD 010-08-94), so this aligns with international safety standards.\n\n**When:** The work must be completed by **5 January 1995** (the revised effective date).\n\n**Why it matters:** This is a **life-critical safety fix**. A loose or detached fan in flight could cause engine failure, loss of control, or debris damage. ADs are legally binding — ignoring them grounds the aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-optica-4-fan-shaft-extension","history":"/api/acts/ad-optica-4-fan-shaft-extension/history","analysis":"/api/acts/ad-optica-4-fan-shaft-extension/analysis","conflicts":"/api/acts/ad-optica-4-fan-shaft-extension/conflicts","importantCases":"/api/acts/ad-optica-4-fan-shaft-extension/important-cases","documents":"/api/acts/ad-optica-4-fan-shaft-extension/documents"}}