{"id":"F2009L02785","name":"AD/B747/212 Amdt 1 - Modular Avionics Warning Electronic Assembly","slug":"ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":79971,"registerId":"commonwealth-F2009L02785-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/B747/212 Amdt 1 | Modular Avionics Warning Electronic Assembly | 8/2009 |\n| ------------------ | -------------------------------------------- | ------ |\n\n| Applicability: | Model 747-400 and 747-400F series aeroplanes equipped with a modular avionics warning electronic assembly (MAWEA) power supply Part Number (P/N)285T0035-201. |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Check the status page of the engine indication and crew alerting system (EICAS) for any MAWEA failure. |\n| | 2. If any failure of the MAWEA or the loss of any visual, aural, or tactile alert is detected during any Requirement 1 check replace the power supplies of the MAWEA with new or modified power supplies having P/N 285T0035-202Mod A, in accordance with either Boeing Service Bulletin (SB) 747-31-2288, dated 17 December 1998, or Revision 1, dated 28 January 1999; or with new, modified, or serviceable power supplies having P/N 285T0035-202 Mod A,P/N 285T0035-10, or P/N 285T0035-11, in accordance with Boeing SB747-31-2288, Revision 2, dated 18 November 1999. |\n| | Note 1: Page 59 of Boeing Service Bulletin 747-31-2288, Revision 1, incorrectly references the Boeing 767 AMM as the appropriate source of service information for accomplishment of the removal and installation of the power supply. However, the correct reference is the Boeing 747 AMM. |\n| | Note 2: Boeing Component Service Bulletin 285T0035-31-07, dated December 17, 1998, describes procedures for modifying MAWEA power supplies having P/N 28T0035-201 to 285T0035-202 Mod A. |\n| | 3. If not already accomplished, replace MAWEA power supplies having P/N 285T0035-201, with new or modified power supplies having P/N 285T0035-202 Mod A; or new, modified, or serviceable power supplies having P/N285T0035-9, P/N 285T0035-10, or P/N 285T0035-11, in accordance with SB 747-31-2288, or Revision 1, or Revision 2. |\n| | After the effective date of this Directive only SB 747-31-2288 Revision 2 may be used to accomplish MAEWA power supply replacement unless later revisions of the SB have been approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to the equivalent Requirements of FAA AD 2001-11-08. |\n\n| | 4. MAWEA power supply P/N 285T0035-201 may not be installed on any aeroplane as a replacement part. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 3: FAA AD 2001-11-08 Amdt 39-12250 refers. |\n| Compliance: | For Requirement 1 - Before every flight until the MAWEA power supply is replaced in accordance with Requirement 2 or Requirement 3. |\n| | For Requirement 2 - Before further flight. |\n| | For Requirement 3 - Within six months after the effective date of this Directive. |\n| | For Requirement 4 - As of the effective date of this Directive. |\n| | This Amendment becomes effective on 30 July 2009. |\n| Background: | The FAA received a report advising that during a production test flight of a Model 747-400 series aeroplane the flight test crew noticed a power supply failure on the status page of the EICAS. Investigation revealed the automatic bench test procedure for the MAWEA overstressed the 5.7 volt over-voltage clamp circuit which resulted in the failure of the circuit to protect the warning cards in the MAWEA. |\n| | A slow failure of the MAWEA power supply could result in the gradual degradation of available visual, aural and tactile alerts which could result in flight crew not being aware of and not taking immediate or appropriate action in the event of an unsafe condition occurring. |\n| | The original issue of this Directive required repetitive checks to detect failures of the MAWEA power supply and if necessary, corrective action. The Directive also provided for an optional terminating action. |\n| | This Amendment increased the applicability to include all 747-400 and 747-400F series aeroplanes with a P/N 285T0035-201 MAWEA power supply and made the terminating action mandatory. |\n| | The original issue of this Directive became effective on 22 September 1999. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n16 June 2009","sortOrder":0},{"sectionNumber":"AD/B747/212 Amdt 1","sectionType":"part","heading":"AD/B747/212 Amdt 1","content":"## AD/B747/212 Amdt 1","sortOrder":1},{"sectionNumber":"Modular Avionics Warning Electronic Asse","sectionType":"part","heading":"Modular Avionics Warning Electronic Assembly","content":"## Modular Avionics Warning Electronic Assembly","sortOrder":2},{"sectionNumber":"8/2009","sectionType":"part","heading":"8/2009","content":"## 8/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original directive (effective September 1999) required repetitive checks and made permanent replacement optional. This Amendment (effective July 2009) significantly expanded the scope: it increased applicability to cover all 747-400 and 747-400F series aircraft with the affected part (not just some), and converted the optional 'terminating action' into a mandatory requirement with a 6-month deadline. It also imposed an absolute prohibition on installing the faulty part, going beyond mere detection and repair."},"complexity_factors":["Multiple specific part numbers (P/N 285T0035-201, -202 Mod A, -9, -10, -11) with subtle distinctions between acceptable replacements","Cross-references to external Boeing Service Bulletins (SB 747-31-2288) with three different revision dates and specific applicability rules","Conditional logic: different compliance timelines depending on whether failure is detected (immediate) versus preventive replacement (6 months)","Nested exceptions and clarifications: Note 1 corrects an error in the referenced Boeing documentation; Note 2 provides modification procedures; Note 3 references equivalent FAA directive","Reference to foreign regulatory approval (FAA AMOC — Alternate Method of Compliance) for future revisions","Amendment structure requires understanding of 'original issue' versus 'this Amendment' to grasp what changed"],"plain_english_summary":"This AD mandates removal of a faulty MAWEA power supply (P/N 285T0035-201) on certain Boeing 747-400/400F aircraft because it can fail gradually and silence critical visual, aural, and vibration warnings. Operators must check EICAS before flight until replacement, replace any failed units before the next flight, retrofit all affected units within six months, and may not install the old part after 30 July 2009. The rule makes the permanent safety fix compulsory."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment expanded the directive's applicability to include all 747-400 and 747-400F aeroplanes fitted with MAWEA power supply P/N 285T0035-201 and converted the previously optional terminating action into a mandatory replacement requirement, thereby increasing the number of affected aircraft and making replacement compulsory rather than optional."},"complexity_factors":["Technical specificity: multiple exact part numbers (285T0035-201; acceptable replacements 285T0035-202 Mod A, 285T0035-10/11/9) increases procedural precision.","Multiple compliance actions: repetitive pre-flight checks until replacement (Requirement 1), immediate replacement if failure detected (Requirement 2), mandatory replacement within six months (Requirement 3), and a ban on reinstalling the old part (Requirement 4).","Interaction with manufacturer documents: mandatory use of Boeing Service Bulletin 747-31-2288 and its revisions, plus a Component Service Bulletin for modification procedures.","Revision and approval constraint: only Revision 2 may be used after the effective date unless later FAA-approved AMOCs are accepted, creating regulatory interdependence.","Expanded applicability: Amendment broadened applicability to all 747-400/400F aircraft with the affected P/N and converted the optional terminating action to mandatory, changing compliance footprint."],"plain_english_summary":"This directive requires operators of Boeing 747-400 and 747-400F aeroplanes fitted with MAWEA power supply P/N 285T0035-201 to perform pre-flight status checks and to replace that unit with specified new or modified power supplies, and forbids reinstalling the old P/N. The stated reason is that the older supply can fail slowly and degrade visual, aural or tactile alerts; operators and maintenance providers therefore bear the inspection and replacement costs and must follow specified Boeing service bulletins."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly","history":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly/history","analysis":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly/analysis","conflicts":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly/conflicts","importantCases":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly/important-cases","documents":"/api/acts/ad-b747-212-amdt-1-modular-avionics-warning-electronic-assembly/documents"}}