{"id":"F2006B06996","name":"AD/SF340/67 - Nose Wheel Hub Heat Treatment","slug":"ad-sf340-67-nose-wheel-hub-heat-treatment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48611,"registerId":"commonwealth-F2006B06996-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/67 - Nose Wheel Hub Heat Treatment","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)  \nSAAB SF340 Series Aeroplanes\n\nAD/SF340/67 Nose Wheel Hub Heat Treatment 1/99\n\nApplicability: SAAB SF340A, serial numbers SF340A-004 through \\-159, and 340B, serial numbers 340B-160 through -451.\n\nRequirement: Action in accordance with SAAB Aircraft Service Bulletin 340-32-116 Revision 1.\n\nNote: LFV AD 1-134 refers.\n\nCompliance: Unless already accomplished, before 5 February 1999.\n\nThis Airworthiness Directive becomes effective on 28 January 1999.\n\nBackground: The manufacturer of the nose wheel hubs has determined that some hub castings were not properly heat treated during a special process designed to decrease the porosity.\n\nThe affected parts have a decrease in strength and removal is required as a precaution against possible loose bearing cups and a decreased fatigue life.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with a narrow, specific safety purpose. It addresses exactly one manufacturing defect in one aircraft component for specific aircraft serial numbers. There is no indication of scope creep; the directive precisely targets the identified heat treatment issue."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined applicability criteria (aircraft models and serial number ranges)","Single, clear compliance requirement referencing an external technical document","No nested exceptions or conditional logic","No cross-references to other legislation beyond a single note about a related foreign directive","Straightforward temporal deadline (single fixed date)"],"plain_english_summary":"This is a **safety order for specific SAAB aeroplanes** (the SF340A and SF340B series). It requires owners or operators of these aircraft to fix a manufacturing defect in the nose wheel hubs.\n\n**What the problem is:**\nSome nose wheel hubs were not properly heat-treated during manufacturing. This process was supposed to make the metal less porous (full of tiny holes). Because this step was missed or done incorrectly, the wheel hubs are weaker than they should be. This creates two risks: bearing cups could come loose, and the hubs could fail from metal fatigue sooner than expected.\n\n**Who must act:**\nAnyone who owns or operates SAAB SF340A aircraft with serial numbers 004 through 159, or SF340B aircraft with serial numbers 160 through 451.\n\n**What they must do:**\nFollow the manufacturer's official repair instructions (Service Bulletin 340-32-116 Revision 1). This likely means inspecting, replacing, or re-treating the affected nose wheel hubs.\n\n**When:**\nThe fix must be completed before 5 February 1999, unless it has already been done.\n\n**Why it matters:**\nThis is a **preventive safety measure**. The Civil Aviation Safety Authority is mandating this action to prevent potential wheel failures during landing or taxiing, which could cause accidents."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD, as presented, targets a specific subset of SAAB SF340 serial numbers and mandates the actions in SAAB Service Bulletin 340-32-116 Revision 1 with a specified compliance date. The text contains no indication that the scope has been expanded or narrowed from an earlier intent; it sets a narrow, product-specific scope and prescribes the remedy and deadline."},"complexity_factors":["Narrow applicability to a defined set of serial numbers reduces scope complexity (Applicability).","Technical action delegated to a specific manufacturer service bulletin simplifies procedural detail but requires reference to an external document (Requirement).","Firm compliance deadline and effective date impose a clear timeline (Compliance; Effective date).","Cross-reference to another authority document (LFV AD 1-134) introduces a small additional lookup requirement (Note).","Technical nature of the remedy (heat-treatment/part removal) creates operational complexity for maintenance providers, not regulatory complexity (Background; Requirement)."],"plain_english_summary":"The AD mandates that operators of SAAB SF340A (S/N SF340A-004 to -159) and SF340B (S/N 340B-160 to -451) carry out the maintenance in SAAB Service Bulletin 340-32-116 Rev 1 to remove/rectify nose wheel hubs that were inadequately heat treated and may have reduced strength and fatigue life. Compliance was required before 5 Feb 1999 (effective 28 Jan 1999); owners/operators pay for the work and maintenance organisations perform it."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment","history":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment/history","analysis":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment/analysis","conflicts":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment/conflicts","importantCases":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment/important-cases","documents":"/api/acts/ad-sf340-67-nose-wheel-hub-heat-treatment/documents"}}