{"id":"F2006B02846","name":"AD/B737/144 - Taxi Light Assembly","slug":"ad-b737-144-taxi-light-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42188,"registerId":"commonwealth-F2006B02846-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/B737/144 Taxi Light Assembly 7/2000 D","sectionType":"part","heading":"AD/B737/144 Taxi Light Assembly 7/2000 DM","content":"# AD/B737/144 Taxi Light Assembly 7/2000 DM\n\nApplicability: Model 737-100, -200, -300, -400 and -500 series aeroplanes that are not equipped with a Grimes Aerospace taxi light assembly having Part Number (P/N) 50-0199-9, 50-0199-11, 50-0128-1A, 50-0128-1MA, 50-0128-3A or 50-0128-3MA.\n\nRequirement: 1. Perform a detailed visual inspection to detect damage (including cracking, corrosion, deformation, or evidence of impact) of the taxi light assembly mounted on the nose landing gear of the aeroplane.\n\nNote 1: For the purposes of this Directive, a detailed visual inspection is defined as an intensive visual inspection of a specific structural area, system, installation or assembly to detect damage, failure or irregularity. Available lighting is normally supplemented with a direct source of lighting at an intensity deemed appropriate by the inspector (i.e., the person performing the inspection).\n\nInspection aids such as mirrors, magnifying glasses, etc., may be used. Surface cleaning and elaborate access procedures may be necessary.\n\n    2. If any damage of the taxi light assembly is detected during the inspection performed in accordance with Requirement 1 of this Directive, replace the existing taxi light assembly with a new or serviceable taxi light assembly in accordance with the applicable maintenance manual. If the existing taxi light assembly is replaced with a Grimes Aerospace taxi light assembly having P/N 50-0199-9, 50- 0199-11, 50-0128-1A, 50-0128-1MA, 50-0128-3A or 50-0128-3MA; no further action is required by this Directive.\n\n    3. Replace the existing taxi light assembly with a Grimes Aerospace taxi light assembly having P/N 50-0199-9, 50-0199-11, 50-0128-1A, 50-0128-1MA, 50- 0128-3A or 50-0128-3MA; in accordance with the applicable maintenance manual. Such replacement constitutes terminating action for the Requirement 1 repetitive inspections.\n\nNote 2: FAA AD 2000-08-17 Amdt 39-11703 refers.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted airworthiness directive addressing a specific safety issue with a particular aircraft component. The scope remains tightly focused on the taxi light assembly issue as originally intended."},"complexity_factors":["Single, clearly defined applicability (specific Boeing 737 models with explicit exclusion for certain part numbers)","Straightforward three-step requirement structure (inspect → repair if damaged → optional permanent replacement)","Only one defined term ('detailed visual inspection') with clear explanation in Note 1","Minimal cross-referencing (single reference to FAA AD 2000-08-17 in Note 2, for information only)","No nested exceptions or conditional logic beyond the initial applicability filter","Short document (approximately 300 words of substantive content)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Boeing 737-100/200/300/400/500 series to perform detailed inspections of the nose-gear taxi light assembly for cracks, corrosion, bending or impact, unless already fitted with specified Grimes Aerospace part numbers. Damaged assemblies must be replaced; installing one of the listed Grimes models is terminating action that stops repetitive inspections. It addresses an identified unsafe condition with those assemblies."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD stays within the narrow safety-corrective scope typical of airworthiness directives: it targets taxi-light assemblies on specified 737 models, requires inspection and replacement if damaged, and offers a specific terminating modification. It does not broaden its regulatory reach beyond fixing the identified component (no expansion into unrelated systems, no new operational restrictions, and no new certification requirements)."},"complexity_factors":["Short document: three operative requirements plus two notes","Single defined inspection term: \"detailed visual inspection\" (Note 1) with practical guidance","One conditional branch: if damage is found then replace; replacement with listed P/Ns terminates inspections","Small, explicit list of affected aircraft models and six specific P/Ns","One external cross-reference to FAA AD 2000-08-17"],"plain_english_summary":"**What this directive does (mechanical effect)**\n\n- It applies to Boeing 737-100, -200, -300, -400 and -500 series aircraft that do NOT already have a Grimes Aerospace taxi light assembly with one of these part numbers (P/N): 50-0199-9, 50-0199-11, 50-0128-1A, 50-0128-1MA, 50-0128-3A or 50-0128-3MA. (Applicability)\n\n- It requires a detailed visual inspection of the taxi light assembly mounted on the nose landing gear to look for damage (cracks, corrosion, deformation, impact evidence). (Requirement 1)\n  - The AD defines a \"detailed visual inspection\" as an intensive inspection using good lighting, mirrors, magnifiers, surface cleaning and access procedures where necessary. (Note 1)\n\n- If damage is found, the taxi light assembly must be replaced with a new or serviceable unit in accordance with the maintenance manual. If the replacement is one of the listed Grimes P/N assemblies, no further action under this AD is required. (Requirement 2)\n\n- Voluntary (or mandatory, if chosen by the operator) replacement of the existing taxi light assembly with one of the listed Grimes P/N assemblies is an approved terminating action: once that Grimes part is installed in accordance with the maintenance manual, the repetitive inspections required by Requirement 1 are no longer required. (Requirement 3)\n\n- The AD cross-references FAA AD 2000-08-17. (Note 2)\n\n**Who this affects**\n\n- Aircraft owners and operators of the listed Boeing 737 models that are not already fitted with the specified Grimes taxi-light assemblies.\n- Maintenance organisations and licensed engineers who perform the inspections and replacements.\n\n**Why it matters (stated purpose and practical implications)**\n\n- The issuing authority states the measure is taken to correct an identified unsafe condition with the taxi light assembly. The practical effect is to force inspection and, if necessary, replacement to eliminate a potentially unsafe part on the nose gear.\n\n**Costs, incentives and implementation points (practical testing of the stated purpose)**\n\n- Who pays: the aircraft owner/operator pays for the inspection work, any cleaning/access work, and for replacement parts and labour if replacement is required (Requirements 1–3).\n\n- Who decides: a maintenance inspector/engineer performs the defined \"detailed visual inspection\" and decides whether the assembly is damaged and must be replaced (Requirement 1 and Note 1). Installation must follow the applicable maintenance manual.\n\n- Behaviour changes required: operators must schedule and perform the inspection; if damage is found they must replace the assembly; operators may choose to replace the assembly with one of the listed Grimes P/Ns to avoid the need for repetitive inspections. Replacing with a listed Grimes assembly is the explicit path to stop repeat inspections (Requirement 2–3).\n\n- Incentives and market effect: the AD creates a clear financial incentive for affected operators to purchase and install the listed Grimes assemblies (they terminate the inspection requirement). That is a factual effect of the terminating-action rule (Requirement 3).\n\n- Compliance burden and operational costs: the AD imposes inspection labour and possible aircraft downtime. If replacement is required, there is the additional parts cost, labour cost and any scheduling impacts from removing the aircraft from service.\n\n- Implementation risk and practicalities: the AD specifies a \"detailed visual inspection\" that may require lighting, mirrors, magnification, surface cleaning and access procedures; these practical requirements may extend inspection time and complexity depending on aircraft configuration and accessibility (Note 1).\n\n- Trade-offs and opportunity costs: owners must weigh inspection and possible replacement costs now against the ongoing burden of periodic inspections if they retain the existing assembly. Installing a terminating part shifts costs to an up‑front capital purchase but removes ongoing inspection costs.\n\n**Summary sentence**\n\nThe AD mandates an immediate, defined visual check of the nose-gear taxi light assembly for certain 737 variants, requires replacement if damage is found, and offers a specified replacement parts list from Grimes Aerospace that, if installed, ends the need for repeated inspections (Requirements 1–3)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-144-taxi-light-assembly","history":"/api/acts/ad-b737-144-taxi-light-assembly/history","analysis":"/api/acts/ad-b737-144-taxi-light-assembly/analysis","conflicts":"/api/acts/ad-b737-144-taxi-light-assembly/conflicts","importantCases":"/api/acts/ad-b737-144-taxi-light-assembly/important-cases","documents":"/api/acts/ad-b737-144-taxi-light-assembly/documents"}}