{"id":"F2009L03128","name":"AD/B737/359 - Outboard Landing Light Wire Bundles","slug":"ad-b737-359-outboard-landing-light-wire-bundles","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":80859,"registerId":"commonwealth-F2009L03128-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/359 | Outboard Landing Light Wire Bundles | 9/2009 |\n| ----------- | ----------------------------------- | ------ |\n\n| Applicability: | Model 737-100, -200, -200C, -300, -400 and -500 series aeroplanes, as identified in Boeing Service Bulletin (SB) 737-28-1241, Revision 1, dated 31 August 2007. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. For Model 737-300, -400 and -500 series aeroplanes identified in Boeing Alert Service Bulletin (ASB) 737-33A1140, dated 22 May 2006 - Accomplish either of the following actions: |\n| | a. Deactivate the outboard landing lights by accomplishing all of theactions specified in Part 1 of the Accomplishment Instructions of ASB737-33A1140, or |\n| | b. Modify the wiring to the outboard landing lights by accomplishing all of the actions specified in Part 2 of the Accomplishment Instructions of ASB737-33A1140. |\n| | Note 1: The Master Minimum Equipment List (MMEL) prohibits dispatching an aeroplane for night operations with deactivated outboard landing lights in the event that either of the inboard landing lights fail. Operators should note that, if the outboard landing lights are deactivated in accordance with Part 1 of ASB737-33A1140 there is no MMEL relief allowing for this configuration for night operations should any inboard landing light fail. |\n| | 2. For all aeroplanes - Accomplish following actions in accordance with737-28-1241, Revision 1: |\n| | a. Replace the wire bundles for the landing lights and fuel shutoff valves with new, redesigned wire bundles and carry out the related investigative, other specified, together with corrective actions, as applicable. The related investigative, other specified and corrective actions must be done before further flight after the replacement. |\n| | b. Carry out detailed inspection for any broken, damaged, or missing fairleads, any damaged or missing grommets and any chafed or damaged wires or wire bundles in the four electrical junction boxes of the main wheel well, and do the applicable corrective actions. The corrective actions must be done before further flight after the inspection. |\n\n| | c. Replace the electrical connectors and backshell clamps with new, improved electrical connectors and backshell clamps, as applicable. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | For Model 737-300, -400 and -500 series aeroplanes identified in ASB 737-33A1140, accomplishing the applicable Requirement 2 actions terminates the Requirement 1 actions. |\n| | For aeroplanes identified as Groups 1 and 2 in SB 737-28-1241, Revision 1 - Actions accomplished before the effective date of this Directive in accordance with SB737-28-1241, dated 7 April 2006, are acceptable for compliance with Requirement 2. |\n| | For all aeroplanes - Actions accomplished before the effective date of this Directive in accordance with Part 2 of the Accomplishment Instructions of SB 737-28-1241 are acceptable for compliance with Requirement 2.b. |\n| | Later revisions of the above SBs, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2009-14-04 are considered acceptable for compliance with the equivalent Requirements of this Directive. |\n| | Note 2: FAA AD 2009-14-04 Amdt 39-15954 refers. |\n| Compliance: | For Requirement 1 - Within 180 days after the effective date of this Directive. |\n| | For Requirement 2 - Within 60 months after the effective date of this Directive. |\n| | This Airworthiness Directive becomes effective on 27 August 2009. |\n| Background: | This Directive results from reports of uncommanded engine shutdowns and burned and damaged wire bundles associated with the outboard landing lights and engine fuel shutoff valves.The Directive is issued to prevent a hot short between the outboard landing light and fuel shutoff valve circuits, which could result in an uncommanded engine shutdown. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n15 July 2009","sortOrder":0},{"sectionNumber":"AD/B737/359","sectionType":"part","heading":"AD/B737/359","content":"## AD/B737/359","sortOrder":1},{"sectionNumber":"Outboard Landing Light Wire Bundles","sectionType":"part","heading":"Outboard Landing Light Wire Bundles","content":"## Outboard Landing Light Wire Bundles","sortOrder":2},{"sectionNumber":"9/2009","sectionType":"part","heading":"9/2009","content":"## 9/2009","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive stays within the original safety-focused purpose: to eliminate a wiring-induced hot-short risk that could cause uncommanded engine shutdowns. The measures (deactivate or rewire for certain subgroups; replace wire bundles, connectors and clamps; inspect junction boxes) directly address that hazard. There is no substantive expansion of scope beyond corrective and preventive electrical/maintenance work tied to the identified circuits and components; the directive permits prior compliant work and FAA-approved AMOCs, but those are procedural flexibilities rather than scope expansions."},"complexity_factors":["Two-tiered requirements (Requirement 1 applies only to 737-300/-400/-500 identified in a specific ASB; Requirement 2 applies to all listed models)","Conditional compliance paths for Requirement 1 (deactivate lights OR modify wiring)","Multiple compliance timeframes (180 days for Req 1; 60 months for Req 2)","Cross-references to multiple Boeing service documents (ASB 737-33A1140, SB 737-28-1241 Rev 1 and earlier versions)","Acceptance of prior work and later SB revisions if approved as FAA AMOC (administrative dependency on FAA decisions)","Operational constraint note referencing MMEL (interaction between maintenance option and operational rules)","Requirement-specific “before further flight” timing for investigative/corrective actions (tight sequencing and immediate grounding risk)","Parts replacement obligations spanning bundles, connectors and backshell clamps (multiple hardware changes)"],"plain_english_summary":"**What this instrument does (mechanics)**\n\n- Applies to Boeing 737 series aeroplanes of specific older models (737-100, -200, -200C, -300, -400 and -500) as identified in Boeing Service Bulletin (SB) 737-28-1241 Revision 1.\n\n- Establishes two sets of mandatory actions to address a wiring hazard between the outboard landing lights and the engine fuel shutoff valve circuits that has been associated with burned wiring and uncommanded engine shutdowns.\n\n - Requirement 1 (for 737-300, -400 and -500 identified in Boeing Alert Service Bulletin (ASB) 737-33A1140 dated 22 May 2006): operators must either\n - (a) deactivate the outboard landing lights using the steps in Part 1 of that ASB; or\n - (b) modify the wiring to the outboard landing lights using the steps in Part 2 of that ASB.\n - Compliance time for Requirement 1: within 180 days of the directive taking effect.\n - Practical note: deactivating the outboard lights is operationally constrained by the Master Minimum Equipment List (MMEL) — if an inboard landing light then fails, the aeroplane may not be dispatched for night operations.\n\n - Requirement 2 (for all affected aeroplanes): operators must\n - (a) replace the wire bundles for the landing lights and the fuel shutoff valves with redesigned bundles and carry out the required investigative and corrective tasks (these corrective actions must be completed before further flight after replacement);\n - (b) perform a detailed inspection of the four electrical junction boxes in the main wheel well for missing/damaged fairleads or grommets and for chafed or damaged wires/wire bundles and complete corrective work before further flight after inspection;\n - (c) replace electrical connectors and backshell clamps with improved parts where applicable.\n - Compliance time for Requirement 2: within 60 months of the directive taking effect.\n\n- Completing Requirement 2 for the 737-300/-400/-500 aircraft listed in the ASB will terminate the Requirement 1 obligations for those aeroplanes.\n\n- The directive accepts certain prior compliance actions (work done to earlier versions of the listed SBs and Part 2 work done before the directive’s effective date) and allows later revisions of the SBs if those revisions are approved by the U.S. FAA as an Alternate Method of Compliance (AMOC).\n\n- Effective date recorded in the instrument: 27 August 2009.\n\n**Who this affects**\n\n- Aircraft owners/operators of the specific Boeing 737 models identified in the referenced service bulletins.\n- Maintenance organisations and MROs that perform the wiring replacements, inspections and connector/backshell changes.\n- Parts suppliers who provide the redesigned wire bundles, improved connectors and clamps.\n\n**Why it matters (stated purpose, then practical effects and trade-offs)**\n\n- Stated purpose: to prevent a hot short (an electrical short producing heat) between the outboard landing light and fuel shutoff valve circuits that could cause an uncommanded engine shutdown. The background cites reports of burned/damaged wire bundles and engine shutdowns.\n\n- Practical effects and trade-offs:\n - Safety benefit: reducing the risk of wiring damage and unintended engine shutdowns by insulating/removing the faulty wiring arrangement and improving connectors.\n - Direct cost to operators: parts, labour and aircraft downtime to carry out replacements, inspections and any corrective actions; the aggregate cost will depend on fleet size, availability of parts and maintenance capacity.\n - Operational constraint if choosing deactivation (Requirement 1(a)): deactivating outboard lights is a cheaper/faster interim fix but restricts night operations under the MMEL if an inboard lamp then fails.\n - Timing trade-off: a short-term compliance option (180 days) is provided for the specific 737-300/-400/-500 group, while a longer window (60 months) is allowed for full fleet wiring and connector remediation—this staggers cost and maintenance scheduling but extends the period during which some aircraft remain at higher risk unless they chose the earlier option.\n - Implementation risk and compliance burden: inspections require correct identification of damaged components and immediate corrective action before further flight; improper installation of redesigned bundles or connectors could negate intended benefits, so certified maintenance actions are necessary.\n - Regulatory discretion and flexibility: the directive accepts previous work done to earlier SBs and allows FAA-approved AMOCs and later SB revisions, which lowers duplication of effort but requires either FAA or CASA administrative acceptance.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: aircraft operators/owners bear the costs (parts, labour, downtime); maintenance organisations incur the work but are paid by operators per contract or service arrangements.\n- Who decides: operators choose which compliance path applies (for the specified 737-300/-400/-500s they can elect deactivation or wiring modification), but maintenance work must follow the referenced Boeing service documents and regulatory acceptance; CASA enforces compliance and accepts FAA AMOCs as allowed.\n- Behaviour changes required: operators must schedule inspections and either deactivate or modify wiring as required, replace wire bundles/connectors/clamps where applicable, and document corrective work. Maintenance programmes and spare-part procurement must be adjusted to accommodate the mandated replacements within the given compliance windows."},"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":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope. It addresses a specific wiring defect in specific Boeing 737 models as originally intended. The directive does not expand beyond its original safety purpose of preventing hot shorts between landing light and fuel shutoff valve circuits."},"complexity_factors":["Multiple overlapping applicability groups (737-100/200/200C vs 737-300/400/500) with different requirements","Cross-references to three separate Boeing Service Bulletins (SB 737-28-1241, ASB 737-33A1140, and earlier SB 737-28-1241 dated 7 April 2006)","Conditional compliance paths: Requirement 1 offers two alternative actions (deactivation vs modification), with Requirement 2 superseding Requirement 1 for certain models","Nested exceptions and grandfathering clauses: work done before the effective date under specific earlier SB versions counts as compliance","Reference to foreign regulatory equivalence (FAA AD 2009-14-04 and AMOC approvals)","Operational restriction note (MMEL prohibition on night dispatch) that creates a practical compliance trap for operators choosing the deactivation option"],"plain_english_summary":"This AD orders mandatory fixes to certain Boeing 737-100/200/200C/300/400/500 airplanes after wiring for outboard landing lights was found close enough to engine fuel-shutoff wiring to risk “hot shorts” and unintended engine shutdowns. Affected operators (those listed in Boeing SB 737-28-1241) must either deactivate or rework the outboard-light wiring on -300/-400/-500 types within six months, and complete a full harness replacement and inspections across all affected models within five years. Noncompliance is not permitted."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles","history":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles/history","analysis":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles/analysis","conflicts":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles/conflicts","importantCases":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles/important-cases","documents":"/api/acts/ad-b737-359-outboard-landing-light-wire-bundles/documents"}}