AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AS 355/52 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 355/52
Amdt 1
TR Head Pitch Change Plate Bearing Spacer 13/2004
Applicability: AS 355 helicopters, versions E, F, F1, F2 and N, fitted with the tail rotor pitch change rotating plates, all part numbers, on which Eurocopter modification (Mod) 07 6554 has not been embodied.
This Airworthiness Directive (AD) does not apply to post-mod 076550 pitch change plate assembly part number 350A33-2030-00.
Requirement: 1. Identify the position of the spacer and the tail rotor pitch change rotating plate as per provisions of paragraph 2.B.1 of Eurocopter AS355 Alert Service Bulletin (ASB) 05.00.33 R1 dated 15 March 2004 or later revision approved by DGAC / EASA.
2. a. Monitor position of the spacer and the tail rotor pitch change rotating plate for alignment as per provisions of paragraph 2.B.2 of ASB 05.00.33 R1 or later revision approved by DGAC / EASA.
The inspection detailed in requirement 2 may be performed by the pilot-in- command, in which case, a certification is to be made by entering AD/AS 355/52 Amdt 1 against the daily inspection certification on the maintenance release. A copy of this directive and of the requirement document must be carried in the helicopter.
2. b. If the paint index marks are aligned, embody Mod 076550 as per the provisions of paragraph 2.B.3 of ASB 05.00.33 R1 or later revision approved by DGAC / EASA.
2. c. If the paint index marks are mis-aligned, embody Mod 076550 as per the provisions of paragraph 2.B.4 of ASB 05.00.33 R1 or later revision approved by DGAC / EASA.
Note 1: DGAC Airworthiness Directive F-2000-223-059 R1 as approved by EASA reference number 2004-9370 dated 7 September 2004 refers.
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/52 Amdt 1 (continued)
Compliance: 1. Unless previously accomplished, at the latest within 10 flying hours after the effective date of this AD.
2.a. Daily, after the last flight of the day.
2.b. Not later than the next “T” basic inspection.
2.c. With-in 25 flying hours from detection of the misalignment.
Note 2: Compliance to the original issue of AD/AS 355/52 is an acceptable alternate to this amendment and no further action is required.
This Amendment becomes effective on 23 December 2004.
Background: This amendment of the Airworthiness Directive reflects changes in the document referred to, in the original issue of the AD, namely revision 1 of Eurocopter AS 355 ASB 05.00.33 and revision 1 of DGAC AD F-2000-223-059. The changes are in the effectivity list and there is no difference in the technical contents.
There have been reports of rotation of the bearing spacers in AS355 tail rotor. Such rotation indicates that the inner bearing race may be rotating on its shaft. Rotation may cause excessive wear and cut the rotating plate, which will cause deterioration and loss of pitch control of the tail rotor.
The original issue of the directive addressed unsafe condition caused by the loss of pitch control of the tail rotor.
The original issue of this airworthiness directive became effective on 14 June 2000.
James Coyne
Delegate of the Civil Aviation Safety Authority 8 November 2004
The above AD is notified in the Commonwealth of Australia Gazette on 1 December 2004.
Overview
The Airworthiness Directive AD/AS 355/52 Amendment 1, issued in 2004, pertains specifically to Eurocopter AS 355 (Twin Ecureuil) Series Helicopters equipped with tail rotor pitch change rotating plates, excluding those that have already incorporated Eurocopter modification 07 6554. This legislative instrument was enacted by the Civil Aviation Safety Authority (CASA) to address an identified unsafe condition related to the rotation of bearing spacers in the tail rotor, which could lead to excessive wear, cutting of the rotating plate, and ultimately, a deterioration in the pitch control of the tail rotor. The primary objective of this directive is to ensure the safe operation of these helicopters by requiring specific actions to be taken to rectify any detected issues with the tail rotor pitch change plate and bearing spacer alignment. Compliance with this directive is mandatory to mitigate the risk of loss of pitch control, which could compromise the safety of flight operations.
Scope and Application
The Airworthiness Directive (AD) AD/AS 355/52 Amendment 1 pertains specifically to Eurocopter AS 355 Twin Ecureuil Series Helicopters, versions E, F, F1, F2, and N, which are equipped with tail rotor pitch change rotating plates. This directive applies to these aircraft models unless they have already incorporated Eurocopter modification (Mod) 07 6554, as it targets a particular unsafe condition related to the rotation of bearing spacers within the tail rotor mechanism. This directive does not apply to aircraft that have been fitted with post-modification 076550 pitch change plate assembly part number 350A33-2030-00. The AD applies nationally across Australia, reflecting its issuance by the Civil Aviation Safety Authority (CASA) as a delegate of the Commonwealth of Australia. Compliance with this AD is mandatory for the specified aircraft models and is enforced through routine inspections and maintenance checks, as outlined in the directive, ensuring the continued airworthiness of these helicopters by mitigating the risk of tail rotor pitch control failure.
Key Provisions
This Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under section 39.1(1) of the Civil Aviation Safety Regulations (CASR) 1998, mandates specific actions to be taken on Eurocopter AS 355 (Twin Ecureuil) Series Helicopters to correct an unsafe condition. The AD applies to AS 355 helicopters, versions E, F, F1, F2, and N, fitted with the tail rotor pitch change rotating plates, excluding those that have already undergone Eurocopter modification (Mod) 07 6554, and specifically excludes post-mod 076550 pitch change plate assembly part number 350A33-2030-00. The requirements outlined in the directive involve identifying the positions of the spacer and the tail rotor pitch change rotating plate as per Eurocopter AS355 Alert Service Bulletin (ASB) 05.00.33 R1 or later revisions approved by DGAC/EASA, monitoring the alignment of these components, and implementing Mod 076550 if the paint index marks are misaligned. If performed by the pilot-in-command, a certification must be made and a copy of the directive carried in the helicopter.
Operators of the affected aircraft must adhere to the directive's requirements by identifying and monitoring the specified components, and implementing the necessary modifications within specified timeframes. The initial compliance must occur within 10 flying hours of the AD's effective date, with daily inspections following the last flight of the day. If the alignment is found to be misaligned, the modification must be completed within 25 flying hours of detection. Additionally, compliance with the next "T" basic inspection is required. The directive notes that compliance with the original AD/AS 355/52 is acceptable, and no further action is required if it has already been implemented.
Failure to comply with the Airworthiness Directive can result in significant consequences. The AD specifies that non-compliance with the requirements may lead to unsafe conditions that can compromise the aircraft's airworthiness. The directive does not explicitly state penalties, but non-compliance can lead to enforcement actions by CASA, which may include fines, suspension, or revocation of airworthiness certificates, and potential criminal charges for serious breaches. The exact penalties would be determined based on the specific circumstances and the severity of the non-compliance.