{"id":"F2007L04021","name":"AD/DAUPHIN/92 - Tail Rotor Pitch Control Shaft","slug":"ad-dauphin-92-tail-rotor-pitch-control-shaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":160811,"registerId":"commonwealth-F2007L04021-current","compilationNumber":null,"startDate":"2026-04-04","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter SA 360 and SA 365 (Dauphin) S","sectionType":"division","heading":"Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters","content":"### Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters\n\n| AD/DAUPHIN/92 | Tail Rotor Pitch Control Shaft | 11/2007 |\n| ------------- | ------------------------------ | ------- |\n\n| Applicability: | Eurocopter SA 365 N1, AS 365 N2 and AS 365 N3 helicopters, all serial numbers, equipped with an aluminium Tail Rotor Blade Pitch Control Shaft with Part Number (P/N) 365A33.6161.20 or 365A33.6161.21.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Replace all P/N 365A33.6161.20 and 365A33.6161.21 aluminium Tail Rotor Blade Pitch Control Shafts with a steel P/N 365A33.6214.20 shaft in accordance with Eurocopter AS365 Alert Service Bulletin (ASB) 01.00.59.2. Do not install P/N 365A33.6161.20 and 365A33.6161.21 aluminium Tail Rotor Blade Pitch Control Shafts on any helicopter.Note: EASA AD 2007-0220 dated 13 August 2007 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| Compliance:    | 1. Before 31 December 2007.2. From 31 December 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n|                | This Airworthiness Directive becomes effective on 25 October 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| Background:    | During a recent incident, the pilot of a Model AS 365 N2 helicopter noticed loss of control of the Tail Rotor. A decision was made to continue the flight to the nearest airport and an uneventful run-on landing was made. Subsequent investigation showed that the Tail Rotor Blade Pitch Control Shaft P/N 365A33.6161.21 had broken. This failure occurred in the main section of shaft sliding area, which appeared to have been damaged by peening. For that reason the origin of the crack, which developed under fatigue loading, could not be determined. Most likely, accidental damage (e.g. shock impact) is thought to have caused the initiation of a crack in the hard tungsten-carbide deposit on the shaft. Damage of this kind cannot be detected through normal inspection methods. This condition, if not corrected, could lead to further cases of control shaft failure and consequent loss of tail rotor control. EUROCOPTER has developed a steel control shaft, P/N 365A33.6214.20, that is less sensitive to shock-induced damage. For this reason, this AD requires replacement of the affected aluminium control shafts. |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n7 September 2007","sortOrder":0},{"sectionNumber":"AD/DAUPHIN/92","sectionType":"part","heading":"AD/DAUPHIN/92","content":"## AD/DAUPHIN/92","sortOrder":1},{"sectionNumber":"Tail Rotor Pitch Control Shaft","sectionType":"part","heading":"Tail Rotor Pitch Control Shaft","content":"## Tail Rotor Pitch Control Shaft","sortOrder":2},{"sectionNumber":"11/2007","sectionType":"part","heading":"11/2007","content":"## 11/2007","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted airworthiness directive addressing a specific mechanical failure mode in specific helicopter models. The scope remains precisely limited to the identified safety defect and mandated replacement part."},"complexity_factors":["Single, unambiguous requirement (replace specific part with specific part)","Only two part numbers affected, clearly identified","Simple two-stage compliance deadline (before 31 Dec 2007, and from 31 Dec 2007)","No defined terms section, no cross-references to other legislation beyond a single reference to a Eurocopter service bulletin","Straightforward causal chain in background (failure mode → risk → solution)","Document is essentially a formatted safety notice rather than a legislative instrument with operative provisions"],"plain_english_summary":"CASA mandates that operators of certain Eurocopter Dauphin SA 365 N1/N2/N3 helicopters replace specified aluminium tail‑rotor pitch control shafts with steel versions by the end of 2007. \n\nThe compulsory safety action follows an in‑flight loss of tail‑rotor control from an aluminium shaft that can crack after unnoticed impact, posing a potentially catastrophic risk."},"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 directive's scope matches the stated safety objective in the text: replace aluminium tail‑rotor pitch control shafts P/N 365A33.6161.20/.21 on specified SA 365 variants with steel P/N 365A33.6214.20 and ban reinstallation of the aluminium parts (Applicability; Requirement). It does not broaden applicability beyond those models or parts."},"complexity_factors":["Narrow technical applicability to specific helicopter models and two aluminium part numbers (Applicability).","Mandatory, one‑time replacement with a specified steel part and explicit prohibition on reinstalling the aluminium parts, so action is prescriptive but simple to audit (Requirement).","Fixed compliance timeline with an effective date and a completion deadline, creating a short scheduling window for operators (Compliance: effective 25 October 2007; compliance before 31 December 2007).","Failure mechanism difficult to detect by normal inspection (peening/shock leading to fatigue cracks), which motivated a parts‑change remedy rather than inspection regimes (Background).","Operators must source and install the new P/N 365A33.6214.20 shaft, imposing direct procurement and maintenance costs on aircraft owners/operators (Requirement).","Cross-reference to an EASA airworthiness directive, indicating regulatory alignment across authorities (Requirement: refers to EASA AD 2007-0220).","Limited regulatory discretion: the AD specifies part numbers and method (Eurocopter AS365 ASB 01.00.59.2), leaving little room for alternative compliance without approval (Requirement)."],"plain_english_summary":"**What it does:** Requires replacing specified aluminium tail-rotor pitch-control shafts with a steel part (P/N 365A33.6214.20) and forbids reinstalling the aluminium shafts.  \n\n**Who it affects and why it matters:** Applies to Eurocopter SA 365 N1, AS 365 N2 and AS 365 N3 helicopters fitted with P/N 365A33.6161.20 or 365A33.6161.21; the change addresses fatigue and shock‑induced damage that can cause sudden tail‑rotor control loss."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft","history":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft/history","analysis":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft/analysis","conflicts":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft/conflicts","importantCases":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft/important-cases","documents":"/api/acts/ad-dauphin-92-tail-rotor-pitch-control-shaft/documents"}}