{"id":"F2006B02511","name":"AD/AS 355/59 Amdt 3 - Main Rotor Starflex Star","slug":"ad-as-355-59-amdt-3-main-rotor-starflex-star","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41767,"registerId":"commonwealth-F2006B02511-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AS 355/59 Amdt 3 - Main Rotor Starflex Star","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AS 355/59 Amdt 2 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\n![](image.001.png)\n\nEurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\nAD/AS 355/59\n\nAmdt 3\n\n  \nMain Rotor Starflex Star 7/2002\n\nApplicability: Model AS 355 helicopters, versions E, F, F1, F2, and N; equipped with Starflex Stars part number 350A31.1916.00 mounted on main rotor hubs without MOD 076221 incorporated.\n\nRequirement: 1. Inspect in accordance with Eurocopter Alert Telex 05.00.37 R2; and,\n\n2. Modify in accordance with Eurocopter Alert Service Bulletin 62.00.26 (MOD 076221).\n\nNote 1: Requirement 2 is now terminating action for Requirement 1\\. Note 2: DGAC AD 2001-558-064(A) R3 refers.\n\nCompliance: 1. Unless the initial inspection is already accomplished, before further flight after 11 July 2002. Thereafter on completion of each flight following rotor stoppage.\n\n2. Before 31 May 2002, unless already accomplished.\n\nThe compliance time for Requirement 2 remains unchanged by this issue.\n\nThis Directive shall be entered on the Maintenance Release as maintenance required. The required visual inspection may be performed and certified by a Pilot in Command who has been trained to do the inspection by an appropriately qualified person. In this case, a copy of the Requirement document and this Directive is to be carried in the aircraft.\n\nThis amendment becomes effective on 11 July 2002.\n\nBackground: Reports were received of several occurrences of rapid bonding failure of the metal bush that is installed on the Starflex star arm ends. In some cases, these incidents caused the pilots to land quickly due to strong vibrations in the cabin.\n\nAmendment 1 corrected the Requirement document number.\n\nEurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\nAD/AS 355/59 Amdt 3 (continued)\n\nAmendment 2 required the incorporation of MOD 076221, in addition to the currently required inspection.\n\nAmendment 3 is issued in response to a revision of the related DGAC AD which excludes Starflex stars mounted on main rotor hubs post MOD 076221 from the scope of this Directive.\n\nAmendment 2 of this Airworthiness Directive became effective on 13 March 2002.\n\nAmendment 1 of this Airworthiness Directive became effective on 21 February 2002.\n\nThe original issue of this Airworthiness Directive became effective on 23 November 2001.\n\n![](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 31 May 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 19 June 2002.","sortOrder":0}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD evolved beyond its original, narrow inspection-only focus. The original AD required inspections; Amendment 2 added a mandatory modification (MOD 076221) as an ultimate corrective action. Amendment 3 then narrowed the scope by explicitly excluding Starflex stars already mounted on hubs post-MOD 076221 from the AD’s applicability. In short, the instrument moved from inspection-only to a two-step regime (inspect until the hub modification is installed), and then clarified that aircraft already modified are outside the directive’s scope."},"complexity_factors":["Short text (single AD) with straightforward structure: Applicability, Requirement, Compliance, Background","3 external cross-references to manufacturer documents/DGAC AD (Eurocopter Alert Telex 05.00.37 R2; Alert Service Bulletin 62.00.26; DGAC AD 2001-558-064(A) R3)","Two-tier requirements where Requirement 2 is terminating action for Requirement 1 (a simple conditional, not deeply nested)","Several effective dates and compliance deadlines including one earlier compliance date (31 May 2002) that is inconsistent with the AD effective date (11 July 2002), adding administrative confusion","Allowance for pilot-performed inspection if trained (an exception to usual maintenance certification rules)","Multiple amendments (original AD + Amendments 1–3) incorporated into the single document, requiring readers to track changes"],"plain_english_summary":"**What this instrument does (mechanics)\n\n- This is an airworthiness directive (AD) that applies to Eurocopter AS 355 helicopter models E, F, F1, F2 and N that are fitted with a specific component: the Starflex Star part number 350A31.1916.00 mounted on main rotor hubs that have not had MOD 076221 fitted (Applicability).\n\n- It requires two actions: (1) a recurring visual inspection of the Starflex star arms in accordance with Eurocopter Alert Telex 05.00.37 R2 (Requirement 1), and (2) modification of the main rotor hub in accordance with Eurocopter Alert Service Bulletin 62.00.26 (MOD 076221) (Requirement 2). The modification, when done, ends the need for the recurring inspection (Note 1).\n\n- Timing (Compliance): the initial inspection must be done before the next flight after 11 July 2002 if it has not already been performed, and thereafter after each flight following rotor stoppage. The modification (MOD 076221) was required to have been done before 31 May 2002 unless already accomplished; the AD states the compliance time for Requirement 2 remains unchanged (Compliance).\n\n- The visual inspection may be done and signed off by a Pilot in Command provided the pilot has been trained by an appropriately qualified person; when a pilot performs it, a copy of the requirement and the AD must be carried on board (Maintenance release / certification note).\n\nWhy the AD was issued (safety rationale)\n\n- The background states there were several occurrences of rapid bonding failure of the metal bush that fits on the Starflex star arm ends. Some failures produced strong cabin vibration and prompted pilots to make precautionary landings. The AD is intended to detect such failures by inspection and to eliminate the unsafe condition by installing MOD 076221 (Background).\n\nWho pays, who decides, and what changes in behaviour\n\n- Who decides: the Civil Aviation Safety Authority (CASA) delegate issued the AD under the relevant CAR subregulation.\n- Who pays: aircraft operators (owners/operators) bear the direct costs — performing the recurring inspections, possible pilot training for inspection certification, and performing the MOD 076221 modification (parts, labour, aircraft downtime). Maintenance organisations or Eurocopter-authorised agents may capture the modification work and ancillary services.\n- Behavioural change: operators must add a pre-flight/post-rotor-stop visual check to normal procedures and either perform a one-off modification to remove the inspection requirement or continue doing the recurring inspections until the modification is installed. Pilots authorised by an appropriately qualified person may perform the visual check instead of an aircraft maintenance engineer for the inspection task.\n\nImplementation, costs, incentives and trade-offs (analyst's assessment)\n\n- Direct costs and opportunity cost: inspections are time-consuming after each flight that follows a rotor stoppage; repeated inspections increase crew/ground time and reduce available flight hours. The mandated modification is a one-off cost (parts and labour) plus downtime; completing it ends the recurring inspection burden. Operators therefore face a trade-off: pay once for the mod or incur ongoing inspection labour costs and possible operational disruption.\n\n- Compliance burden and flexibility: the AD is prescriptive — operators cannot opt out. However, allowing trained pilots to carry out the visual inspection reduces cost and dependence on licensed maintenance staff for that particular check, which eases operational burden for some operators.\n\n- Market effects: the AD creates demand for parts and for organisations capable of carrying out MOD 076221 and the inspections. Independent maintenance providers are able to offer this work, so the intervention increases business for the maintenance sector; eurocopter-authorised workshops may also capture demand depending on contractual and warranty relationships.\n\n- Implementation risk and clarity: the AD cross-references Eurocopter service documents and a DGAC AD. Those cross-references mean operators must obtain and follow the specified manufacturer instructions. Timing in the AD is potentially confusing: the modification compliance date listed (before 31 May 2002) precedes the AD effective date (11 July 2002) — the text states that the compliance time for Requirement 2 remains unchanged, which means operators who had not already completed the mod by that earlier date were out of compliance unless they had complied earlier. That sequencing increases administrative complexity and requires operators to check their own maintenance history carefully.\n\n- Concentrated benefits and diffuse costs: the safety benefit (reduced risk of rotor vibration/failure) accrues mainly to each affected operator and their passengers/crew (concentrated benefit). Costs (inspection time, modification expense) are distributed across operators of the affected fleet (diffuse cost). The AD does not on its face create a direct financial subsidy or differential treatment between operators.\n\n- Bureaucratic discretion and legal effect: the AD is mandatory under the CAR subregulation cited. The CASA delegate revoked and replaced the previous ADs, showing administrative discretion in updating requirements as the manufacturer or foreign authority (DGAC) revised its guidance.\n\nNotes and cross-references to read alongside this AD\n\n- Operators must follow the Eurocopter Alert Telex 05.00.37 R2 for the inspection method and Alert Service Bulletin 62.00.26 for the modification (Requirement). The AD refers to DGAC AD 2001-558-064(A) R3 for related guidance (Note 2).\n\nBottom line\n\n- If you operate an affected AS 355 with the specified Starflex part and without MOD 076221, you must inspect the part as specified after 11 July 2002 and either complete the mandatory MOD 076221 (if not already done) or continue inspecting after each flight following rotor stoppage. The AD shifts short-term costs to operators (inspection time and/or modification expense) to reduce the risk of rotor-component bonding failure and resultant in-flight vibration."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 3 of an existing Airworthiness Directive. The amendments have remained tightly focused on the original safety issue (Starflex Star bonding failures). Amendment 1 corrected a document number, Amendment 2 added the modification requirement, and Amendment 3 simply refined the applicability to exclude already-modified helicopters. The scope has not expanded beyond the original safety purpose."},"complexity_factors":["Short, single-purpose document (2 pages) focused on one specific mechanical issue","Only 2 main requirements with clear compliance dates","Minimal defined terms — uses standard aviation terminology (AD, MOD, DGAC) without extensive definitions","Simple conditional logic: 'unless already accomplished' appears twice but is straightforward","Cross-references to external Eurocopter documents (Alert Telex and Service Bulletin) but these are standard industry references rather than legislative cross-references","Clear terminating action (modification ends inspection requirement) — simple causal relationship","Background section provides plain English explanation of the safety risk"],"plain_english_summary":"This AD affects Eurocopter AS355 (Twin Ecureuil E/F/F1/F2/N) helicopters and targets a Starflex Star main-rotor bushing bonding failure that can cause severe vibrations and emergency landings. It mandates visual inspections per Eurocopter Alert Telex 05.00.37 R2 before flying after 11 July 2002 and after every flight once rotors stop, unless MOD 076221 (per ASB 62.00.26) is installed by 31 May 2002, which terminates inspections.\n\nPilots may perform and certify the inspection if trained; the AD and service documents must be carried on board."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star","history":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star/history","analysis":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star/analysis","conflicts":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star/conflicts","importantCases":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star/important-cases","documents":"/api/acts/ad-as-355-59-amdt-3-main-rotor-starflex-star/documents"}}