{"id":"F2006B02521","name":"AD/AS 355/71 Amdt 1 - Electrical Power System","slug":"ad-as-355-71-amdt-1-electrical-power-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41777,"registerId":"commonwealth-F2006B02521-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Do not use the landing light outside the","sectionType":"part","heading":"Do not use the landing light outside the landing and take-off phases","content":"# Do not use the landing light outside the landing and take-off phases\n\n    3. Replace the non temperature-compensated contactors with temperature- compensated circuit breakers, in compliance with the instructions described in either ASB No. 24.00.14 or ASB 24.00.14 Revision 1 (corresponds to MOD 073019).\n\nFollowing embodiment of this modification the Requirement 1 AFM revisions and the Requirement 2 placard may be removed.\n\nNote 2: DGAC AD 2000-339-060(A) R3 refers.\n\nCompliance: For Requirements 1 & 2 \\- As of the effective date of this Directive.\n\nFor Requirement 3 \\- Before 1 December 2003.\n\nThis Amendment becomes effective on 30 October 2003.\n\nBackground: AD/AS 355/55 was issued following several reports of complete loss of the electrical power generating systems, except for the direct battery power, on AS 355 helicopters. The failures occurred at a high outside air temperature (above 25°C) during long duration flights (more than one hour with landing light on).\n\nAD/AS 355/55 required an AFM revision, which limits the landing light operation to take-off and landing and introduces emergency procedures for loss of the electrical power generating systems. The Directive also required a placard to be fitted advising the pilot of the landing light operational limitation.\n\nThe original issue of this Directive superseded the earlier AD, limited applicability to helicopters equipped for IFR flights, extended applicability to cover electrical master boxes with all part numbers and introduced a terminating action.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The amendment shifts scope from imposing only an operational restriction and placard (as required by AD/AS 355/55) to mandating a hardware modification that serves as a terminating action. Specifically, it requires replacement of non temperature-compensated contactors with temperature-compensated circuit breakers per ASB No. 24.00.14 (Requirement 3) and states that once this modification is embodied the AFM revision and placard (Requirements 1 & 2) may be removed (text: 'Following embodiment of this modification the Requirement 1 AFM revisions and the Requirement 2 placard may be removed'). This changes who must act and how long the operational limits apply: operators must either accept immediate operational limits or bear the cost and logistics of the retrofit by 1 December 2003 (Compliance section)."},"complexity_factors":["Mix of operational limitation and a hardware retrofit as an alternative (operational rules vs terminating action).","Technical specificity of the required part change: 'non temperature-compensated contactors' to 'temperature-compensated circuit breakers' referencing ASB No. 24.00.14 or Revision 1.","Multiple compliance timelines: Requirements 1 & 2 effective immediately; Requirement 3 mandatory by 1 December 2003 (Compliance section).","Cross-references to external service documentation and a foreign authority (ASB No. 24.00.14 / Revision 1 and DGAC AD 2000-339-060(A) R3).","Operational-document changes that can be reversed after modification: AFM revision and placard removal contingent on embodiment (text: 'Following embodiment ... may be removed').","Background incidents constrain the safety rationale (high OAT >25°C, flights >1 hour with landing light on) which link operational behaviour to hardware risk."],"plain_english_summary":"This directive addresses repeated electrical-generator failures on AS 355 helicopters by limiting landing-light use to take-off and landing unless a hardware retrofit is installed. Operators must either follow the operational restriction and placard immediately or complete a specified modification—replacing non-temperature-compensated contactors with temperature-compensated circuit breakers per ASB No. 24.00.14 (or Revision 1)—by 1 December 2003. Once the retrofit is embodied the AFM revision and placard can be removed."},"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":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of addressing electrical power system failures in AS 355 helicopters. It narrows applicability to IFR-equipped helicopters (a refinement, not expansion) and adds a terminating action (the hardware modification), which is a natural progression toward resolving the safety issue rather than scope creep."},"complexity_factors":["Short, focused scope addressing a single technical issue on one aircraft type","Only 3 requirements with clear, sequential numbering","Minimal defined terms — relies on standard aviation terminology (AFM, IFR, ASB)","Single cross-reference to a French aviation authority document (DGAC AD 2000-339-060(A) R3)","Simple conditional logic: Requirement 3 terminates Requirements 1 and 2 once completed","Background section provides clear context without legal obfuscation"],"plain_english_summary":"This AD for AS 355 helicopters fixes a design fault where using the landing light in hot conditions could cause complete electrical power loss, leaving only battery power and risking instruments and radios. It requires AFM changes to limit landing-light use and add electrical-failure procedures, a cockpit placard warning, and replacement of contactors with temperature‑compensated circuit breakers as the permanent fix.\n\nIt affects AS 355 owners and operators—especially IFR-equipped aircraft—and prevents potentially catastrophic electrical failures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system","history":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system/history","analysis":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system/analysis","conflicts":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system/conflicts","importantCases":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system/important-cases","documents":"/api/acts/ad-as-355-71-amdt-1-electrical-power-system/documents"}}