{"id":"F2006B01882","name":"AD/A320/136 Amdt 3 - Digital Distance and Radio Magnetic Indicators","slug":"ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41078,"registerId":"commonwealth-F2006B01882-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/136 Amdt 3 - Digital Distance and Radio Magnetic Indicators","content":"![](image.001.png)\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png) \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/A320/136 Amdt 2 and issues the following AD under subregulation 39.1 (1) of CASR 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.\n\n![](image.001.png) \n\nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/136\n\nAmdt 3\n\n \nDigital Distance and Radio Magnetic Indicators 2/2004\n\nApplicability: Airbus A319 series aeroplanes, all serial numbers (MSM) after 0909, fitted with a Thales Avionics (formerly Sextant or Sextant Avionique) Digital Distance and Radio Magnetic Indicator (DDRMI) with a part number (P/N) listed below.\n\nAirbus A320 series aeroplanes, all MSN after 0843, fitted with a Thales Avionics DDRMI with a P/N listed below.\n\nAirbus A321 series aeroplanes, all MSN after 1011, fitted with a Thales Avionics DDRMI with a P/N listed below.\n\nAll other Airbus A319/A320/A321 series aeroplanes fitted with a Thales Avionics DDRMI with a P/N listed below and having a serial number (S/N) different from the S/N recorded in the Aircraft Inspection Report (AIR) delivered from the production line, or with a Thales Avionics DDRMI that has been repaired after May 1999.\n\n```html\n

DDRMI Part Numbers

63543-150-3

63543-250-1

63543-253-2

63543-150-2

63543-250-2

63540-041-2

63543-150-1

\n```\n\nThis Directive is not applicable to aeroplanes with Airbus modification 32414 or 32415 or 32416 or 32417 embodied during production or whilst in service in accordance with Airbus Industrie Service Bulletin (SB) A320-34-1264 Revision 1.\n\nRequirement: 1. Unless previously accomplished in accordance with the original issue of this Directive, deactivate the DDRMI in accordance with paragraph 4 of Airbus Industrie All Operator Telex (AOT) A320-34A1262 Revision 01 dated 21 August 2002.\n\n2. Dispatch with an inoperative standby compass (Master Minimum Equipment List \\[MMEL\\] reference 34-22-02 a) is limited to a ‘B’ rectification interval.\n\nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/136 Amdt 2 (continued)\n\nNote 1: This Airworthiness Directive supersedes the MMEL for the inoperative DDRMI despatch condition (reference 34-57-01). Therefore this Airworthiness Directive may supersede any Minimum Equipment List (MEL) limitation concerning the DDRMI in accordance with AOT A320-34A1262 Revision 01 paragraph 3.5.\n\nNote 2: DGAC Telegraphic AD 2002-458(B) R2 refers.\n\nCompliance: For Requirement 1 \\- Remains unchanged as ‘Before 2 October 2002’.\n\nFor Requirement 2 \\- As of the effective date of this Amendment. This Amendment becomes effective on 19 February 2004.\n\nBackground: Airbus received reports from two operators advising of DDRMI circuit breakers tripping, followed by loss of VOR and DME sources for navigation and displays. Investigations showed the DDRMI power transformer had short circuited, leading to leakage of 115 VAC to systems connected to the DDRMI ARINC 429 busses.\n\nThe original issue of this Directive required temporary deactivation of the DDRMI to prevent possible loss of essential equipment due to an in-flight failure of the DDRMI.\n\nAmendment 1 extended the range of affected aircraft to aircraft that may have DDRMI version B power transformers.\n\nAmendment 2 introduces a reference to SB A320-34-1264 Revision 1 as an alternate method of incorporating modification 32414 or 32415 or 32416 or 32417.\n\nThis Amendment corrects the issue date of AOT 34A1262 Revision 01.\n\nThe original issue of this Airworthiness Directive became effective on 29 March 2002.\n\nAmendment 1 of this Airworthiness Directive became effective on 25 September 2002.\n\nAmendment 2 of this Airworthiness Directive became effective on 22 January 2004.\n\n![](image.002.png) \n\nDavid Villiers\n\nDelegate of the Civil Aviation Safety Authority 8 January 2004\n\n![](image.001.png) \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 28 January 2004.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Yes. Since the original AD, the scope was broadened and compliance routes modified: Amendment 1 extended affected aircraft to include DDRMI version B power-transformer variants; Amendment 2 added a Service Bulletin (SB A320‑34‑1264 Rev 1) as an alternate means to embody modifications 32414–32417 (i.e. an alternate compliance pathway); Amendment 3 corrects the AOT issue date. The net effect is a wider set of affected units and an added alternate modification route."},"complexity_factors":["Applicability depends on aircraft model, MSN thresholds and specific DDRMI part numbers (table of P/Ns).","Additional applicability triggers: DDRMI repaired after May 1999 or S/N mismatching the production Aircraft Inspection Report.","Exemptions where Airbus modifications 32414–32417 have been embodied via SB A320‑34‑1264 Revision 1.","Cross-references to Airbus AOT A320‑34A1262 Revision 01 and an Airbus Service Bulletin as mandated compliance/information sources.","Interplay with MMEL/MEL provisions — AD may supersede MEL limitations for DDRMI (operational/dispatch consequences).","Operational constraint: dispatch with inoperative standby compass limited to a ‘B’ rectification interval (affects flight dispatch decisions).","Technical causal chain: electrical failure (power-transformer short) leading to leakage of 115 VAC into ARINC‑429 buses and potential cascade loss of navigation systems.","Multiple amendments and dated compliance deadlines (original AD, Amendment 1, Amendment 2, Amendment 3) requiring attention to effective dates and corrected AOT issue date."],"plain_english_summary":"Requires operators to deactivate certain Thales Digital Distance and Radio Magnetic Indicators (DDRMI) installed on Airbus A319/A320/A321 aeroplanes (part-numbered units, units repaired after May 1999, or with serial-number discrepancies) and limits dispatch with an inoperative standby compass to a ‘B’ rectification interval. The directive follows reports that a DDRMI power transformer can short and leak 115 VAC into ARINC‑429 buses, risking loss of VOR/DME navigation sources; deactivation or incorporation of specified modifications is mandated to address that risk."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This Amendment 3 is a minor technical correction only. It fixes the issue date of a referenced Airbus technical bulletin (AOT) from '21 August 2002' (which was apparently wrong in Amendment 2) to the correct date. The substantive safety requirements and applicability remain identical to the original 2002 directive and its 2004 predecessor. The scope has not expanded beyond addressing the specific DDRMI electrical fault."},"complexity_factors":["Multiple applicability criteria requiring cross-referencing of aircraft serial numbers, part numbers, and modification status","Nested exceptions: applies to certain aircraft EXCEPT those with specific modifications (32414-32417) installed via specific service bulletin","References to external technical documents (Airbus AOT A320-34A1262, Service Bulletin A320-34-1264, DGAC AD 2002-458(B) R2) that are not reproduced in the text","Compliance deadlines vary by requirement and reference historical amendment dates","Interaction with other regulatory instruments (MMEL/MEL limitations) requiring aviation operational knowledge","Technical aviation terminology (ARINC 429 busses, VOR, DME, rectification intervals) assumed to be understood by the target audience"],"plain_english_summary":"This Airworthiness Directive replaces the prior order for Airbus A319/A320/A321 aircraft fitted with certain Thales DDRMI units, requiring operators to deactivate the faulty instrument and follow tightened dispatch limits to address a transformer short that can disable VOR/DME displays. It applies to affected operators (except aircraft already modified), overrides normal MEL relief, and mainly corrects a paperwork error in the referenced Airbus technical bulletin date without changing the safety requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators","history":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators/history","analysis":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators/analysis","conflicts":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators/conflicts","importantCases":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators/important-cases","documents":"/api/acts/ad-a320-136-amdt-3-digital-distance-and-radio-magnetic-indicators/documents"}}