{"id":"F2006B02502","name":"AD/AS 355/48 Amdt 1 - Tail Boom-to-Aircraft Structure Junction Attachment Screws","slug":"ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41758,"registerId":"commonwealth-F2006B02502-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AS 355/48 Amdt 1 - Tail Boom-to-Aircraft Structure Junction Attachment Screws","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AS 355/48 and issues the following AD under subregulation 39.1 (1) of CAR 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\nEurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\nAD/AS 355/48\n\nAmdt 1\n\n  \n\nTail Boom-to-Aircraft Structure Junction Attachment Screws\n\n  \n3/2002\n\nApplicability: Model AS 355 helicopters, versions E, F, F1, F2, and N, equipped with tail boom-to- aircraft structure junction attachment screws part number 22201BC060008L (N5103337287). This directive does not apply to new or overhauled aircraft delivered after 15 May 1997, and aircraft on which no tail boom-to-aircraft structure junction attachment screw was replaced since 1 July 1994 (even if these screws are marked with the letter “M”).\n\nRequirement: Check the marking on the heads of the 23 attachment screws which are located above the cargo compartment floor, and scrap all screws which are marked with the letter “M” on the screw head above the designation “BC”, in accordance with the instructions given in paragraph 2.B.1 of Eurocopter AS350 Alert Service Bulletin No. 01.00.43.\n\nNote: DGAC AD 1997-146-054 (A) R1 refers.\n\nCompliance: Unless already accomplished, within 100 hours time in service after 9 October 1997, or before 31 October 1997; whichever occurs first.\n\nThe compliance time for this amendment remains unchanged. This amendment becomes effective on 21 March 2002.\n\nBackground: This Directive was originally issued in October 1997, as a batch of attachment screws has been found which do not meet the required metallurgical specification.\n\nAmendment 1 has been issued to cover the conversion of the Service Telex into Alert Service Bulletin No. 01.00.43, with no change to technical content.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 5 February 2002\n\n![](image.001.png)\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 27 February 2002.\n\n  \nPage 1 of 1","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 1 only converts the original Service Telex into Alert Service Bulletin No. 01.00.43 without changing technical content or compliance times; applicability and required actions remain the same as the original AD."},"complexity_factors":["Technical specificity: requires checking a precise part number and a two-character marking on screw heads","Narrow applicability with date-based exemptions (delivery/overhaul date and replacement history)","Fixed short compliance window tied to original AD dates (100 hours TIS or a calendar date)","Procedural detail delegated to an external document (Eurocopter AS350 Alert Service Bulletin paragraph 2.B.1)","Legal formality: revocation of the original AD and reissue under CAR 1998 subreg 39.1(1)","Low administrative discretion but nontrivial operational burden for affected operators (inspection/scrap/replace)"],"plain_english_summary":"This AD requires operators of Eurocopter AS 355 helicopters (models E, F, F1, F2, N) fitted with a specified tail-boom attachment screw to inspect the 23 screws above the cargo floor and scrap any showing an “M” above the “BC” marking, following Eurocopter AS350 Alert Service Bulletin instructions. CASA’s delegate mandates the inspection and removal; operators (owners) bear the cost of inspection and replacement. The amendment merely reissues the service instruction format; the technical requirement and compliance timing are unchanged."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment explicitly states it makes 'no change to technical content' from the original 1997 directive. The scope remains precisely targeted at the specific batch of defective screws in specific helicopter models. No expansion of applicability or requirements has occurred."},"complexity_factors":["Single, specific mechanical defect addressed with clear inspection and replacement instructions","Only 2 exemption categories to parse (new/overhauled post-May 1997; no screw replacement since July 1994)","One cross-reference to external technical document (Eurocopter AS350 Alert Service Bulletin No. 01.00.43)","Simple binary compliance trigger: check for 'M' marking → scrap if present","No nested conditional logic, no defined terms section, no sub-delegations","Total length: approximately 300 words across 1 page"],"plain_english_summary":"This AD orders owners of certain Eurocopter AS355 E/F/F1/F2/N helicopters to inspect 23 screws securing the tail boom and scrap any marked “M” (wrong metallurgical spec) above the “BC” marking. Screws with part number 22201BC060008L are affected because they can fail and risk tail‑boom detachment. The compliance deadlines have long passed; the March 2002 action only reissued the original 1997 requirements in Alert Service Bulletin format without technical change."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws","history":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws/history","analysis":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws/analysis","conflicts":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws/conflicts","importantCases":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws/important-cases","documents":"/api/acts/ad-as-355-48-amdt-1-tail-boom-to-aircraft-structure-junction-attachment-screws/documents"}}