AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AS 355/73 and issues the following AD under subregulation 39.1 (1) of CASR 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.
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/73
Amdt 1
Flight Control Stop Screws 9/2004
Applicability: Models AS 355 E, F, F1, F2, and N helicopters; without MOD 073206 or MOD 073102 incorporated.
Components affected: roll, pitch, and collective flight control stops.
Requirement: 1. Action in accordance with paragraph 2.B.1. of Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1.
2. Action in accordance with paragraph 2.B.2. of Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1.
Note: DGAC AD F-2003-322 R1 refers.
Compliance: 1. Within 100 flight hours after 30 October 2003, unless already accomplished.
2. Within 500 flight hours or 1 year after 30 October 2003, whichever occurs first. The compliance time remains unchanged by this issue.
This Amendment becomes effective on 2 September 2004.
Background: A report was received of an incident during a ground run-up with a Model EC 120 helicopter, where it was possible to push the collective lever downward beyond it’s normal position. Investigation revealed that the locknut of the low pitch stop had come loose and that the stop was out of adjustment. The worst case scenario is that of collective low pitch stop maladjustment, which can result in rotor under-speed in an auto-rotation situation.
Amendment 1 is issued in response to a revision of the related DGAC AD, which introduces additional applicability information and revised Requirement document, with no change to the technical content.
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/73 Amdt 1 (continued)
The original issue of this Airworthiness Directive became effective on 30 October 2003.
David Villiers
Delegate of the Civil Aviation Safety Authority 13 July 2004
The above AD is notified in the Commonwealth of Australia Gazette on 11 August 2004.
Overview
The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive (AD) AD/AS 355/73 Amendment 1 in 2004 to address an identified unsafe condition with the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters, specifically those models AS 355 E, F, F1, F2, and N that do not have the Modification 073206 or Modification 073102 incorporated. This directive was enacted following an incident where it was possible to push the collective lever of an EC 120 helicopter beyond its normal position during a ground run-up, due to a loose locknut of the low pitch stop and subsequent maladjustment of the stop. The potential consequence of such an issue is rotor under-speed in an auto-rotation scenario, which poses a significant safety risk. The AD was introduced to ensure compliance with specific actions as outlined in Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1, aiming to rectify the identified unsafe condition and maintain the airworthiness of the affected aircraft.
Scope and Application
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Safety Regulations 1998 applies specifically to Eurocopter AS 355 (Twin Ecureuil) Series Helicopters, including models AS 355 E, F, F1, F2, and N, that do not have modifications MOD 073206 or MOD 073102 incorporated. This directive is concerned with the components of the aircraft's flight control system, namely the roll, pitch, and collective flight control stops. The directive mandates specific actions in response to identified safety concerns, as outlined in Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1, to correct unsafe conditions that may affect the airworthiness of the helicopters. The directive is effective from the specified date and must be complied with within certain timeframes, either within 100 flight hours after 30 October 2003 or within 500 flight hours or 1 year from the same date, whichever comes first. The AD, effective as of 2 September 2004, was issued in response to an incident highlighting the risk of maladjustment in flight control stops, which could lead to critical safety issues such as rotor under-speed during an auto-rotation scenario.
Key Provisions
The Airworthiness Directive (AD) AD/AS 355/73 Amdt 1 (2004) pertains to specific models of the Eurocopter AS 355 Twin Ecureuil series helicopters that lack modifications MOD 073206 or MOD 073102. The AD applies to the AS 355 E, F, F1, F2, and N models. The components affected by this directive are the roll, pitch, and collective flight control stops. The directive requires compliance with specific actions detailed in the Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1, particularly as outlined in paragraphs 2.B.1. and 2.B.2. These actions must be taken within specific timeframes: within 100 flight hours following 30 October 2003 if not already completed, and within 500 flight hours or 1 year following 30 October 2003, whichever occurs first.
Operators and owners of the specified models of the Eurocopter AS 355 series helicopters must adhere to the requirements set forth in the AD. They are obligated to ensure that the actions specified in the Eurocopter Alert Service Bulletin are carried out. Specifically, this includes checking and, if necessary, adjusting the flight control stop screws to prevent the collective lever from being pushed beyond its normal position. This requirement is critical to maintain the airworthiness of the aircraft and to avoid potential hazards such as rotor under-speed in an auto-rotation scenario.
Failure to comply with this AD can result in significant consequences. While the legislation does not explicitly state civil or criminal penalties, non-compliance could lead to the aircraft being deemed unairworthy, which could result in grounding and potential financial penalties. Additionally, there may be implications for the airworthiness certificate of the aircraft, and operators could face scrutiny or enforcement actions from the Civil Aviation Safety Authority (CASA). The directive underscores the importance of adhering to these safety measures to ensure the continued safe operation of the affected helicopters.