AD/Bell 412/50 Breeze-Eastern Rescue Hoist Assembly (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 412/50 Breeze-Eastern Rescue Hoist Assembly 3/2006

Applicability:

All Model AB412 helicopters equipped with rescue hoist, part number BL-20200 series (Breeze-Eastern); without Breeze-Eastern Alert Service Bulletin (ASB) No. BL-12756-1-A25-01 Revision A incorporated.

Requirement:

Action in accordance with Agusta Mandatory Technical Bulletin No. 412-89 original issue, or later ENAC approved revision.

Insert a copy of Agusta Mandatory Technical Bulletin No. 412-89 and a copy of this directive into the Aircraft Flight Manual.  These may be removed when ASB No. BL‑12756-1-A25-01 has been complied with.

Note:  ENAC AD 2002-450 refers.

Compliance:

For Part I of the Requirement document:

Before the next flight after 16 March 2006, unless already accomplished, and before each flight when use of the rescue hoist is anticipated; until accomplishment of ASB No. BL-12756-1-A25-01 Revision A.

For Part II of the Requirement document:

At each flight during operation of the rescue hoist; until accomplishment of ASB No. BL-12756-1-A25-01 Revision A.

This Airworthiness Directive becomes effective on 16 March 2006.

Background:

A cable fracture occurred on a helicopter with a rescue hoist similar to the hoist installed on the Model AB412 helicopter.  The cause of the cable fracture was found to be due to a malfunction of the slow-down feature, and to the crushable bumper that did not function correctly.  The crushable bumper functions as a secondary sacrificial safety device should the slow-down feature fail in the up direction.

David Villiers
Delegate of the Civil Aviation Safety Authority

2 February 2006