{"id":"F2006B10241","name":"AD/GAZELLE/22 Amdt 3 - Torsion Tie Bar","slug":"ad-gazelle-22-amdt-3-torsion-tie-bar","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55899,"registerId":"commonwealth-F2006B10241-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAZELLE/22 Amdt 3 - Torsion Tie Bar","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/GAZZELE/22 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 SA 341 and SA 342 (Gazelle) Series Helicopters\n\nAD/GAZELLE/22\n\nAmdt 3\n\n  \n\nTorsion Tie Bar 3/2003 DM\n\nApplicability: Model SA 341 G and SA 342 J helicopters equipped with torsion tie bars part number:\n\n341A31-4904-00, \\-01, \\-02, \\-03;\n\n341A31-4933-00, \\-01;\n\n704A33-633-270.\n\nRequirement: Action in accordance with the requirements of Eurocopter SA 341/342 Alert Service Bulletin No. 01.29.\n\nNote: DGAC AD 2001-587-041 (A) R2 refers.\n\nCompliance: As specified in the Requirement document.\n\nThis amendment becomes effective on 22 January 2003.\n\nBackground: The DGAC issued an airworthiness directive following the results of a SA 341 G helicopter accident investigation. As a consequence, this Directive requires the removal from service of certain part number main rotor head torsion tie bars.\n\nAmendment 1 introduced further actions as defined in Alert Telex No. 01.28.\n\nAmendment 2 introduced Revision 1 of the referenced Alert Telex that required new flight restrictions and new instructions.\n\nAmendment 3 is issued in response to a revision of the related DGAC AD, which introduces a new Requirement document that incorporates the instructions of Alert Telex No.01.28 and supersedes Alert Telex No. 01.29 R1. This Directive cancels the requirement to return torsion tie bars that are more than 7 years old to the works for checking; and consequently, reduces the calendar limit since installation from 15 years to 7 years, reduces the service life limit from 5,000 flight hours to 600 flight hours, cancels the mandatory daily check of the torsion tie bar tell tale screw, and incorporates a new torsion tie bar part number and operating time limit.\n\nAmendment 1 of this Airworthiness Directive became effective on 5 December 2001.\n\nEurocopter SA 341 and SA 342 (Gazelle) Series Helicopters\n\nAD/GAZELLE/22 Amdt 3 (continued)\n\nAmendment 2 of this Airworthiness Directive became effective on 29 January 2002.\n\nThe original issue of this Airworthiness Directive became effective on 30 September 2001.\n\n![Signature of David Alan Villiers](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 16 January 2003\n\n![](image.001.png)  \nThe above AD is notified in the Commonwealth of Australia Gazette on 22 January 2003.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive has evolved significantly from its original 2001 issue. Originally focused on removal of certain torsion tie bars following an accident, it has expanded through three amendments to incorporate: additional actions from Alert Telexes, new flight restrictions, revised inspection requirements, and finally (in this Amendment 3) a complete overhaul of service life limits and cancellation of previous inspection protocols. The scope has shifted from simple removal requirements to a complex life-limitation and replacement regime."},"complexity_factors":["Multiple amendment history requiring cross-referencing (original + 3 amendments)","References to external documents: Eurocopter Alert Service Bulletin No. 01.29, DGAC AD 2001-587-041 (A) R2, and superseded Alert Telexes 01.28 and 01.29 R1","Specific part number enumeration (6 variants across two part number series)","Nested effective dates (original 2001, Amendments 1-3 across 2001-2003)"],"plain_english_summary":"This AD orders owners/operators of Eurocopter SA 341 G and SA 342 J Gazelle helicopters with certain torsion tie bars to follow Eurocopter Alert Service Bulletin No. 01.29 and replaces the earlier directive. It sharply shortens life limits for affected tie bars (15→7 years; 5,000→600 hours), cancels the old return-for-inspection and daily tell‑tale check requirements, and adds a new approved part number with limits. The changes follow a French accident investigation; non‑compliance grounds the aircraft."},"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":3,"scope_assessment":{"changed":false,"description":"The amendment stays within the original safety-focused purpose of the AD (correcting an unsafe condition on torsion tie bars). It tightens technical limits (shorter calendar and flight-hour limits), changes inspection/return requirements, and adds a part number — but these are refinements of the safety remedy rather than an expansion of the AD's original scope into unrelated areas."},"complexity_factors":["Short, focused AD but relies on an external manufacturer document (Eurocopter Alert Service Bulletin No. 01.29) for the technical steps","Multiple amendments (original AD plus Amendment 1, Amendment 2, and this Amendment 3) that change requirements over time","Several part numbers listed in the applicability (7 distinct part-number families/variants)","Changes to multiple limit types (calendar limit, service-hour limit) and removal of prior inspection/return requirements (conditional changes)","Cross-reference to a foreign regulator's AD (DGAC), adding another normative source to consider","Compliance is defined by reference to the Requirement document rather than spelled out in full in the AD (delegated technical detail)"],"plain_english_summary":"**What this instrument does (mechanically):**\n\n- The Airworthiness Directive (AD) requires operators of certain Eurocopter Gazelle helicopters to take specific actions on the main rotor head torsion tie bars. (See: \"Applicability\", \"Requirement\", \"Compliance\" sections.)\n- It directs compliance with the instructions in Eurocopter SA 341/342 Alert Service Bulletin No. 01.29 (the manufacturer document referenced in the AD). The AD takes effect on the stated effective date.\n\n**Which aircraft and parts are affected:**\n\n- Applies to Eurocopter model SA 341 G and SA 342 J helicopters that have torsion tie bars with the listed part numbers (341A31-4904-00/ -01/ -02/ -03; 341A31-4933-00/ -01; 704A33-633-270). (See: \"Applicability\".)\n\n**Key changes introduced by this amendment (Amendment 3):**\n\n- Replaces the previous ADs and requires action per the revised Eurocopter document that consolidates earlier telex instructions. (See: \"Requirement\"; \"Background\".)\n- Shortens permissible calendar and flight-time limits for affected torsion tie bars:\n  - Calendar limit since installation reduced from 15 years to 7 years.\n  - Service life limit reduced from 5,000 flight hours to 600 flight hours.\n- Cancels the earlier requirement to return torsion tie bars older than 7 years to the manufacturer for inspection.\n- Cancels the mandatory daily check of the torsion tie bar tell-tale screw that had been required under a prior amendment.\n- Adds a new torsion tie bar part number and an associated operating time limit. (See: \"Background\" and amendment summary.)\n\n**Why the AD exists (stated purpose):**\n\n- The AD follows an accident investigation of an SA 341 G helicopter and the related French DGAC directive. Its stated purpose is to correct an identified unsafe condition on the main rotor head torsion tie bars by removing certain parts from service and imposing stricter life limits. (See: \"Background\" and note referring to DGAC AD.)\n\n**Who pays and who decides:**\n\n- The aircraft operators (owners and operators) bear the direct costs: inspections, removal and replacement of torsion tie bars, maintenance labour, parts, and any aircraft downtime. (Implied by the compliance requirements and manufacturer work instructions cited in the AD.)\n- The Civil Aviation Safety Authority (CASA) delegate issued the AD and enforces compliance; the AD requires operators to follow the Eurocopter Alert Service Bulletin as the method of compliance. (See: signature and \"Requirement\".)\n\n**How behaviour must change (practical effects):**\n\n- Maintenance programmes and aircraft records must be updated to reflect the new calendar and flight-hour limits for the listed torsion tie bars.\n- Operators must remove from service any torsion tie bars that exceed the new limits or otherwise meet the removal criteria set out in the referenced Eurocopter document.\n- Operators no longer have to return older tie bars to the manufacturer for checking, and daily tell-tale screw checks are no longer mandated by the AD; however the AD still requires following the new manufacturer instructions.\n\n**Implementation, trade-offs and operational impacts to note:**\n\n- Compliance depends on following an external manufacturer document (Alert Service Bulletin No. 01.29). That creates a dependency: the AD sets the regulatory requirement but delegates the specific technical steps to the manufacturer document (\"Requirement\" and \"Compliance\").\n- Shortening life limits (calendar and hours) increases replacement frequency, raising direct costs and increasing downtime for operators. This also concentrates cost on operators flying the affected models and using the specified part numbers.\n- Cancelling the return-to-works requirement reduces logistical/administrative burden and potential manufacturer workload, but the AD keeps stricter life limits in place — the net operational effect is more frequent part replacement rather than inspection-in-place.\n- Cancelling the daily tell-tale screw check reduces a routine operational task, lowering daily inspection burden, but that change accompanies stricter life limits; operators must trade off fewer daily checks against earlier part replacement.\n- The AD references and aligns with the DGAC (French authority) directive; operators that fly internationally should ensure compliance with both CASA and foreign authority requirements where applicable.\n\n**Bottom line:** The AD updates earlier instructions to require removal from service and replacement of certain torsion tie bars sooner than before, replaces some inspection/return requirements with stricter calendar and flight-hour limits, and requires operators to comply with the Eurocopter Alert Service Bulletin for detailed actions. It shifts costs and operational impact onto helicopter operators (inspection, removal, replacement, downtime), while simplifying some inspection obligations."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar","history":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar/history","analysis":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar/analysis","conflicts":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar/conflicts","importantCases":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar/important-cases","documents":"/api/acts/ad-gazelle-22-amdt-3-torsion-tie-bar/documents"}}