AD/BO 105/28 Tail Rotor Balance Weights (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(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 BO 105 Series Helicopters

AD/BO 105/28 Tail Rotor Balance Weights 9/2009

Applicability:

Eurocopter Canada BO 105 LS A-3 helicopters.

Requirement:

1.    Perform the initial and repeat inspections of the tail rotor balance weights and control levers in accordance with the accomplishment instructions of Eurocopter Canada Alert Service Bulletin (ASB) BO 105 LS 30-12, dated 12 December 2008, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.

2.    If, as a result of the inspections above, the detected damage exceeds the acceptable limits specified in ASB BO 105 LS 30-12; replace the affected parts with serviceable parts.  Replacement of parts does not constitute terminating action for the repetitive inspection requirements of this directive.

Note:  Transport Canada AD CF-2009-12 dated 24 March 2009 refers.

Compliance:

For Requirement 1 - Initially, within the next 2 months or 100 flight hours, whichever occurs first after the effective date of this AD, unless already accomplished.

Thereafter at intervals not exceeding 600 flight hours or 48 months, whichever occurs first.

For Requirement 2 - Before further flight.

This Airworthiness Directive becomes effective on 27 August 2009.

Background:

During a periodical inspection, corrosion was detected on the tail rotor balance weights in the area of the attachment thread.

This condition, if not corrected, could lead to balance weight separation from the tail rotor, resulting in severe vibration and consequent loss of control of the helicopter.

James Coyne
Delegate of the Civil Aviation Safety Authority

15 July 2009