{"id":"F2006L03808","name":"AD/A330/68 - Fight Controls - Back-Up Control Module","slug":"ad-a330-68-fight-controls-back-up-control-module","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":137664,"registerId":"commonwealth-F2006L03808-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A330 Series Aeroplanes","sectionType":"division","heading":"Airbus Industrie A330 Series Aeroplanes","content":"### Airbus Industrie A330 Series Aeroplanes\n\n| AD/A330/68 | Fight Controls - Back-Up Control Module | 13/2006 |\n| ---------- | --------------------------------------- | ------- |\n\n| Applicability: | A330 aircraft, all certified models, all serial numbers, on which Airbus Modification 49144 (install rudder fly by wire) has been embodied during production, except those on which Airbus Modification 55185 has been embodied during production or Airbus Service Bulletin (SB) A330-27-3142 dated 17 August 2006 has been embodied whilst in service. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Perform an operational test of the back-up control module (BCM) and back-up power supply (BPS) by BITE (Built In Test Equipment) in accordance with Airbus SB A330-27-3147 dated 4 August 2006. |\n| | 2. If, as a result of the Requirement 1 operation test, any discrepancies are detected, apply the corrective actions in accordance with SB A330-27-3147. |\n| | 3. Install a modified BCM in accordance with instructions SB A330-27-3142. |\n| | Later approved revisions of the above service bulletins may be utilised to achieve compliance with the relevant Requirements of this Directive. |\n| | Note: EASA AD 2006-0313 refers. |\n| Compliance: | For Requirement 1 - Within 900 hours time in service (TIS) after the effective date of this Directive and, thereafter, at intervals not exceeding 900 hours TIS until the BCM is replaced in accordance with SB A330-27-3142. |\n| | For Requirement 2 - Before further flight after the Requirement 1 operational test. |\n| | For Requirement 3 - No later than 31 December 2008. |\n| | This Airworthiness Directive becomes effective on 21 December 2006. |\n| Background: | The European Aviation Safety Agency (EASA) has advised that during a BCM retrofit campaign, one resistor manufactured by SRT was found with an abnormal resistance drift. This resistor was subject to humidity absorption and then to oxidation, which lead to increase the resistor value. This oxidation has been determined coming from a production quality issue.When the aircraft is in control back up configuration (considered to be an extremely remote case), an incorrect value on these resistors may cause degradation of the BCM piloting laws, potentially leading to erratic motion of the rudder and to possible impact on the Dutch Roll. |\n| | In order to detect a degradation of the BCM piloting laws due to resistor oxidation, this Directive mandates a repetitive ground operational test of the BCM fitted with resistor manufactured by SRT until accomplishment of terminating action (installation of BCM fitted with resistors manufactured by VISHAY). |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n9 November 2006","sortOrder":0},{"sectionNumber":"AD/A330/68","sectionType":"part","heading":"AD/A330/68","content":"## AD/A330/68","sortOrder":1},{"sectionNumber":"Fight Controls - Back-Up Control Module","sectionType":"part","heading":"Fight Controls - Back-Up Control Module","content":"## Fight Controls - Back-Up Control Module","sortOrder":2},{"sectionNumber":"13/2006","sectionType":"part","heading":"13/2006","content":"## 13/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in a specific component (SRT resistors in BCM units) on a specific aircraft type (A330 with Mod 49144). The requirements remain tightly focused on detection and replacement of the defective part without expanding into broader flight control system modifications or other aircraft types."},"complexity_factors":["Single, specific technical subject matter (one aircraft system on one aircraft type)","Only 3 main requirements with clear sequential logic (test → fix if broken → replace)","Straightforward applicability criteria using standard aviation terminology (modification numbers, serial numbers)","Simple compliance timeline structure (repetitive interval + hard deadline)","Minimal cross-referencing (only references to specific Airbus Service Bulletins and one EASA AD)","No nested exceptions or conditional sub-clauses beyond the initial applicability exclusion","Total length is very short (approximately 300 words of substantive content)"],"plain_english_summary":"This AD mandates testing and replacement of the Back‑Up Control Module (BCM) on certain Airbus A330s because some BCMs contain SRT resistors that can absorb moisture, oxidise and fail. If the main system fails, a faulty BCM could cause erratic rudder inputs and Dutch roll. It affects A330s with Mod 49144 (unless later Mod 55185/SB fixed) — requires 900‑hour BITE tests, immediate repair of faults, and BCM replacement by 31 Dec 2008."},"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":4,"scope_assessment":{"changed":false,"description":"Scope remains as originally framed: it applies only to A330s with Airbus Mod 49144 embodied during production, excluding those already embodying Mod 55185 or SB A330-27-3142 (Applicability). The Directive mandates repeated BITE tests every 900 hours TIS until the BCM is replaced (Requirements & Compliance) and sets a terminating-installation deadline (Compliance: no later than 31 December 2008). No text indicates an expansion or contraction of scope beyond these stated limits."},"complexity_factors":["Targeted applicability with exclusions (Applicability: Mod 49144 embodied during production; excludes aircraft with Mod 55185 or SB A330-27-3142 embodied) — narrows who must comply.","Layered compliance steps (Requirement 1: BITE operational test; Requirement 2: corrective actions if discrepancies; Requirement 3: install modified BCM per SB A330-27-3142) — multiple sequential actions.","Recurring inspection burden (Compliance: tests every 900 hours TIS until BCM replacement) — ongoing operational cost and scheduling impact.","Hard deadline for terminating action (Compliance: install modified BCM no later than 31 December 2008) — capital/maintenance timing pressure.","Immediate flight safety constraint (Requirement 2: corrective action before further flight) — operational disruption risk for faults found).","Dependence on manufacturer service bulletins and approved revisions (‘‘Later approved revisions of the above service bulletins may be utilised'') — regulatory acceptance/approval path creates discretionary interaction.","Reference to external regulator AD (Note: EASA AD 2006-0313 refers) — cross-jurisdictional coordination.","Technical cause tied to specific supplier parts (Background: resistor manufactured by SRT vs terminating action replacing with resistors from VISHAY) — supply-chain/parts-tracking complexity."],"plain_english_summary":"This directive requires operators of certain Airbus A330 aircraft (those produced with Airbus Modification 49144 but not those with Mod 55185 or SB A330-27-3142 embodied) to perform a repetitive ground-built-in-test-equipment (BITE) check of the back-up control module (BCM) and back-up power supply, fix any faults found, and install a modified BCM by a set deadline. The measure responds to a production-quality resistor defect (oxidation risk) that could degrade BCM piloting laws and, in an extremely remote configuration, cause erratic rudder motion and affect Dutch Roll behaviour."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a330-68-fight-controls-back-up-control-module","history":"/api/acts/ad-a330-68-fight-controls-back-up-control-module/history","analysis":"/api/acts/ad-a330-68-fight-controls-back-up-control-module/analysis","conflicts":"/api/acts/ad-a330-68-fight-controls-back-up-control-module/conflicts","importantCases":"/api/acts/ad-a330-68-fight-controls-back-up-control-module/important-cases","documents":"/api/acts/ad-a330-68-fight-controls-back-up-control-module/documents"}}