{"id":"F2008L03647","name":"AD/B747/383 - APU Power Feeder Wire Bundle","slug":"ad-b747-383-apu-power-feeder-wire-bundle","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":75309,"registerId":"commonwealth-F2008L03647-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 747 Series Aeroplanes","sectionType":"division","heading":"Boeing 747 Series Aeroplanes","content":"### Boeing 747 Series Aeroplanes\n\n| AD/B747/383 | APU Power Feeder Wire Bundle | 11/2008 |\n| ----------- | ---------------------------- | ------- |\n\n| Applicability: | Model 747-400 and 747-400D series aeroplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin (SASB) 747-24-2257, Revision 1, dated 2 August 2007.                                                                                                                                 |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out a general visual inspection of the power feeder wire bundle of the auxiliary power unit (APU) where it crosses the hydraulic system number 4 return tube to determine if parts are installed to provide separation between the wire bundle and hydraulic tube, in accordance with SASB 747-24-2257,Revision 1. |\n|                | 2. Carry out all the related investigative and corrective actions as specified in the Accomplishment Instructions of SASB 747-24-2257, Revision 1.                                                                                                                                                                          |\n|                | Note 1: Actions accomplished before the effective date of this Directive in accordance with SASB 747-24-2257 dated 18 May 2006, are acceptable for compliance with the corresponding requirements of this Directive.                                                                                                        |\n|                | Later revisions of the SASB 747-24-2257, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-14-14, are considered acceptable for compliance with the equivalent Requirements of this Directive.                                                 |\n|                | Note 2: FAA AD 2008-14-14 Amdt 39-15609 refers.                                                                                                                                                                                                                                                                             |\n| Compliance:    | For Requirement 1 - Before 21 August 2010.                                                                                                                                                                                                                                                                                  |\n|                | For Requirement 2 - Before further flight after the Requirement 1 inspection.                                                                                                                                                                                                                                               |\n|                | This Airworthiness Directive becomes effective on 23 October 2008.                                                                                                                                                                                                                                                          |\n\n| Background: | The FAA has advised of receiving a report that the power feeder wire bundle of the APU was found touching the hydraulic system return tube during inspection of an aeroplane. This directive is issued to prevent insufficient clearance between the wire bundle and hydraulic tube that could lead to chafing of the wire bundle. This chafing could cause arcing and a consequent hydraulic fluid fire in an area outside of the smoke detection and fire extinguishing zone; this condition could result in an uncontrolled fire on the aeroplane. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n9 September 2008","sortOrder":0},{"sectionNumber":"AD/B747/383","sectionType":"part","heading":"AD/B747/383","content":"## AD/B747/383","sortOrder":1},{"sectionNumber":"APU Power Feeder Wire Bundle","sectionType":"part","heading":"APU Power Feeder Wire Bundle","content":"## APU Power Feeder Wire Bundle","sortOrder":2},{"sectionNumber":"11/2008","sectionType":"part","heading":"11/2008","content":"## 11/2008","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety defect identified by the manufacturer and foreign regulator. It has not expanded beyond its original purpose of mandating inspection and correction of the APU wire bundle chafing hazard."},"complexity_factors":["Single, specific technical requirement (visual inspection of one wire bundle location)","Only 2 substantive compliance requirements with clear sequential logic","Minimal defined terms (only standard aviation acronyms: APU, SASB, AMOC, FAA)","No nested exceptions or conditional logic — only a simple grandfathering note for prior compliance","Short document (approximately 300 words of substantive content)","Single external reference document (Boeing Service Bulletin) with clear revision tracking","Straightforward compliance timeline with absolute dates"],"plain_english_summary":"CASA requires operators of Boeing 747‑400 and 747‑400D aircraft in Australia to inspect APU wiring where it crosses a hydraulic return tube and, if wires contact or are too close, install protective separation parts and carry out corrective actions.\n\nThe AD responds to reported chafing/arcing that could ignite hydraulic fluid outside smoke detection and fire‑suppression zones, posing an unseen fire risk. Inspection due before 21 August 2010; AD effective 23 October 2008."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains the original safety focus—to prevent APU feeder wire chafing against hydraulic tubing—and restricts measures to inspection and corrective action per the Boeing service bulletin. Acceptance of prior compliance and FAA‑approved AMOCs adjusts permissible methods but does not expand or narrow the population of affected aircraft or the safety objective."},"complexity_factors":["Narrow applicability: only Model 747-400 and 747-400D (limits affected population).","Relies on an external Boeing Service Bulletin (SASB 747-24-2257 Rev 1) for technical instructions (operators must obtain and follow the SASB).","Cross‑jurisdictional interaction: acceptance of FAA AD 2008-14-14 and FAA‑approved AMOCs creates dependency on FAA approvals.","Two-step compliance schedule: a one‑time visual inspection by a fixed date and corrective actions before further flight if defects are found (requires scheduling and possible AOG/repair downtime).","Low technical complexity of required task (general visual inspection), but corrective actions may vary in scope and require qualified maintenance personnel and parts.","Recordkeeping and proof of compliance required for regulators and may accept prior work if done in accordance with earlier SASB dated 18 May 2006.","Limited regulatory discretion: CASA sets the directive and accepts certain alternate methods but relies on FAA/Boeing documentation for substantive methods."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 747-400 and 747-400D aeroplanes to visually inspect the APU power‑feeder wire bundle where it crosses the hydraulic system No.4 return tube and to carry out any investigative or corrective work specified in Boeing Special Attention Service Bulletin 747-24-2257 Revision 1. Aircraft operators pay for and arrange the inspections and repairs; the Civil Aviation Safety Authority enforces the directive and accepts certain earlier work and FAA‑approved alternate methods. The measure addresses chafing that could cause arcing and a hydraulic‑fluid fire."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle","history":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle/history","analysis":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle/analysis","conflicts":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle/conflicts","importantCases":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle/important-cases","documents":"/api/acts/ad-b747-383-apu-power-feeder-wire-bundle/documents"}}