{"id":"F2006B10550","name":"AD/HS 748/16 - Main and Nose Landing Gear Life Limits","slug":"ad-hs-748-16-main-and-nose-landing-gear-life-limits","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116363,"registerId":"commonwealth-F2006B10550-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 748/16 - Main and Nose Landing Gear Life Limits","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)  British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes\n\n \n\nAD/HS 748/16 Main and Nose Landing Gear Life Limits 5/95\n\nApplicability: All HS 748 aircraft.\n\n \n\nRequirement: Retire from service nose and main landing gear components and associated equipment listed in Dowty Aerospace Landing Gear Service Bulletin (SB) 32-104E.\n\n \n\nCompliance: Retire at the times specified in Dowty Aerospace Landing Gear SB 32-104E Tables 1 to 7 inclusive.\n\n \n\nBackground: The results of extensive fatigue testing indicate that a number of Structurally Significant Items on the main and nose landing gears are life limited and consequently a retirement life is specified.\n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD’s scope is consistent with its stated purpose: it applies to all HS 748 aircraft and mandates retirement of specified main and nose landing gear items at lives listed in Dowty Aerospace SB 32-104E (Applicability; Requirement; Compliance; Background). The instrument does not expand obligations beyond retiring the listed components at the specified times, nor does it add additional inspection or modification mandates in the text supplied."},"complexity_factors":["Clear, single requirement: retire specific landing gear parts listed in an external Service Bulletin (Requirement).","Applicability limited to a single aircraft type (HS 748), reducing regulatory scope (Applicability).","Compliance depends on external document (Dowty SB 32-104E) and its Tables 1–7, so users must consult and interpret that SB (Compliance).","Operational complexity from tracking individual part life histories across airframes and scheduling replacements (Compliance).","Potential logistical complexity if replacement parts are scarce, creating supply‑chain or downtime issues (Requirement, Compliance)."],"plain_english_summary":"### What this directive does\n- This Airworthiness Directive (AD) applies to all British Aerospace (Hawker Siddeley) HS 748 aeroplanes. (Applicability)\n- It requires operators to remove from service (retire) certain main and nose landing gear parts and associated equipment identified in Dowty Aerospace Landing Gear Service Bulletin SB 32-104E. (Requirement)\n- The retirement must occur at the times set out in Tables 1–7 of that Service Bulletin. (Compliance)\n\n### Why it was issued (stated reason)\n- The AD states that extensive fatigue testing showed a number of Structurally Significant Items on the main and nose landing gear are life‑limited; the Service Bulletin therefore specifies retirement lives for those items. (Background)\n\n### Who decides and who pays\n- The regulator (Civil Aviation Safety Authority via this AD) decides the mandatory action by referencing the Dowty SB. (Requirement)\n- Aircraft owners/operators must carry out the retirements and obtain replacement parts; they therefore bear the direct costs of parts, labour and aircraft downtime. (Requirement, Compliance)\n\n### What operators must do and how it changes behaviour\n- Operators must track the life accumulation for the listed parts and remove them from service when they reach the retirement life given in SB 32-104E Tables 1–7. (Compliance)\n- Operators will schedule maintenance and procure replacement components in line with those retirement times, potentially increasing maintenance frequency for affected airframes. (Requirement, Compliance)\n\n### Implementation, compliance burden and risks to watch for\n- Compliance requires accurate life tracking for each listed component and access to SB 32-104E and its Tables 1–7. (Compliance)\n- Costs include replacement parts, technician time, and aircraft downtime; smaller operators with fewer spare aircraft may face proportionally higher operational disruption. (Requirement, Compliance)\n- Possible implementation risks include availability of approved replacement parts and supply delays, which could increase grounding time or interim operational costs. (Requirement, Compliance)\n\n### Effects on markets and incentives (mechanical, not normative)\n- Maintenance and parts suppliers for HS 748 landing gear may see increased demand for replacement components. (Requirement)\n- Operators gain reduced risk of in‑service fatigue failures for the listed parts at the price of recurring replacement costs and scheduling constraints. (Background, Requirement)\n- The rule constrains operator discretion over continued use of specified parts beyond their tested life; operators retain freedom to choose suppliers and timing within the requirement to retire at the specified lives. (Requirement, Compliance)\n\n### Trade‑offs and opportunity costs\n- The AD substitutes predictable replacement costs and scheduled maintenance for the alternative risk of continued service beyond tested lives. (Background)\n- Funds and workshop time spent implementing the retirements cannot be used for other investments or maintenance tasks during the same period. (Requirement, Compliance)\n\nSource sections cited: Applicability; Requirement; Compliance; Background."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive focused specifically on landing gear life limits for one aircraft type. It has not expanded beyond its original purpose."},"complexity_factors":["Very short document (under 200 words)","Only 4 operative paragraphs (Applicability, Requirement, Compliance, Background)","No defined terms section","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Single, clear obligation: retire parts at specified times","Technical details outsourced to external service bulletin (SB 32-104E), keeping the directive itself simple"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for a specific aircraft type: the British Aerospace HS 748 series.\n\n**What it does:**\n- Requires operators to permanently remove from service certain landing gear parts (nose gear, main gear, and related components) once they reach a specific number of flight hours or cycles.\n- The exact retirement times are found in a technical document called **Dowty Aerospace Service Bulletin 32-104E** (Tables 1-7).\n\n**Who it affects:**\n- Anyone who owns or operates an HS 748 aircraft in Australia.\n\n**Why it matters:**\n- Fatigue testing revealed that some landing gear components have a limited safe lifespan. Without this directive, these parts could fail structurally during landing, potentially causing accidents. This rule prevents catastrophic landing gear failures by forcing replacement before metal fatigue becomes dangerous."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits","history":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits/history","analysis":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits/analysis","conflicts":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits/conflicts","importantCases":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits/important-cases","documents":"/api/acts/ad-hs-748-16-main-and-nose-landing-gear-life-limits/documents"}}