AD/BELL 412/53 - Tail Rotor Blade Fwd Tip Weight Retention Block and Aft Tip Closure - 2 (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.

Bell Helicopter Textron 412 Series Helicopters AD/BELL 412/53 Tail Rotor Blade Fwd Tip Weight Retention Block and Aft Tip Closure - 2 13/2007

Applicability: Agusta Model AB412 helicopters, equipped with tail rotor blades part number 212-010-750-009, -011, -105, -107, and -113. Requirement: Action in accordance with Agusta Technical Bulletin 412-88 Revision B, or later ENAC approved revision.

Note: ENAC AD 2005-139 refers. Compliance: Within 100 flight hours after 20 December 2007, unless already accomplished in accordance with AD/BELL 412/44 Amdt 1. This Airworthiness Directive becomes effective on 20 December 2007. Background: Reports were received of five occurrences of missing tail rotor blade forward tip weight retention blocks or aft tip closures that resulted in minor to substantial damage. Such damage could result in loss of a tail rotor blade, and subsequent loss of control of the helicopter.

The requirements of this Directive were previously contained in AD/BELL 412/44 Amdt 1.

David Villiers Delegate of the Civil Aviation Safety Authority