{"id":"F2006B03462","name":"AD/BAe 146/11 - Main Landing Gear - Main Fitting","slug":"ad-bae-146-11-main-landing-gear-main-fitting","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43016,"registerId":"commonwealth-F2006B03462-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/11 - Main Landing Gear - Main Fitting","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 BAe 146 Series Aeroplanes\n\n \n\nAD/BAe 146/11 Main Landing Gear - Main Fitting 2/89\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with British Aerospace BAe 146 Service Bulletin 32-73.\n\n \n\nCompliance: Prior to the main landing gear accumulating 12000 landings or within 1000 landings after 1 March 1989, whichever occurs later.\n\n \n\nBackground:  Fatigue and material defects may be present on the main fitting and on the barrel section of the main fitting. Fatigue and static strength testing has shown that this condition, if not corrected, could lead to collapse of the main landing gear.\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\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection/repair of BAe 146 main landing gear main fittings."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined applicability criterion ('All models')","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional compliance formula with only two variables (landing count vs. date-based deadline)","Single technical reference to external document (Service Bulletin 32-73) without incorporation by reference complexity","No nested exceptions or conditional logic","Straightforward factual background with clear causal chain (defect → potential failure)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders owners and operators of **British Aerospace BAe 146 series aircraft** to inspect and fix a specific safety problem with the **main landing gear** (the wheels that support the plane when it lands).\n\n**The problem:**\nThe \"main fitting\" — a critical structural component of the landing gear — may have **fatigue cracks** (tiny cracks from repeated stress) and **material defects**. Testing showed that if left unchecked, this could cause the landing gear to **collapse**.\n\n**What must be done:**\nOperators must follow the repair instructions in **British Aerospace Service Bulletin 32-73** (a technical manual from the manufacturer).\n\n**When it must be done:**\nBefore the landing gear reaches **12,000 landings**, OR within **1,000 landings after 1 March 1989** — whichever happens later.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains BAe 146 aircraft in Australia.\n\n**Why it matters:**\nThis is a **life-safety issue**. Landing gear collapse during takeoff or landing could cause a catastrophic accident. The directive ensures potentially defective parts are identified and replaced before they fail."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope is clear in the text: it applies to all BAe 146 models and requires compliance with Service Bulletin 32-73 by the stated landing-count/calendar deadlines (Applicability; Requirement; Compliance). The instrument does not indicate any expansion or contraction of scope beyond those terms, and the AD does not amend or exempt categories of aircraft within the stated applicability."},"complexity_factors":["Reference to an external technical document (British Aerospace Service Bulletin 32-73) for the substance of the required work rather than including technical detail in the AD (Requirement).","Compliance metric uses aircraft-specific counters (number of landings) combined with a calendar-based backstop, requiring operators to track usage precisely (Compliance).","Applicability is broad (all models), which increases administrative scope though the AD text itself is short (Applicability).","The AD does not specify costs, cost-allocation, enforcement mechanisms or alternative compliance paths, leaving those operational details to implementers or other regulatory processes (Requirement; Compliance).","Technical subject matter (landing-gear fatigue and static strength) is specialized, so executing the AD requires access to technical expertise and parts, though those specifics are in the service bulletin (Background; Requirement)."],"plain_english_summary":"This Airworthiness Directive (Australia, Civil Aviation Regulations) requires all BAe 146 aircraft to have the main landing-gear main fitting serviced per British Aerospace Service Bulletin 32-73. It must be done before each gear reaches 12,000 landings or within 1,000 landings after 1 March 1989, whichever is later.\n\nThe AD was issued because testing indicated fatigue/material defects in the main fitting that could lead to gear collapse. It mandates the service bulletin’s actions (technical detail delegated there) but does not specify costs or who pays."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting","history":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting/history","analysis":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting/analysis","conflicts":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting/conflicts","importantCases":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting/important-cases","documents":"/api/acts/ad-bae-146-11-main-landing-gear-main-fitting/documents"}}