AD/Bell 412/56 Rescue Hoist Cable 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 412/56 Rescue Hoist Cable Assembly 10/2008 TX

Applicability:

Model AB 412 and AB 412EP helicopters, all serial numbers, that have internal hoist part number 214-070-300-1 (Goodrich part number 42277-1) or external hoist part number BL-10300-60 (Breeze Eastern) or part number BL-20200-SERIES (Breeze Eastern), installed.

Requirement:

1.    Identify the affected rescue hoist cable assemblies and determine the accumulated number of “hoist cycles” for each unit, in accordance with the instructions of Agusta Alert Technical Bulletin 412-126 dated 28 July 2008, or later EASA approved revision, and replace any units that have reached or exceeded the new retirement life limit.

2.    Amend the approved aircraft maintenance programme to incorporate the new life limit, in accordance with Chapter 4 of Agusta Maintenance Manual AB412-MM Revision 6, dated 27 June 2008.

3.    Thereafter, within the thresholds and intervals indicated in Chapter 4 of Agusta Maintenance Manual AB412-MM Revision 6, dated 27 June 2008, replace each rescue hoist cable assembly with a serviceable unit.

If it is not possible to determine the “hoist cycles” and/or date of hoist cable assembly installation, as required by Requirement 1, not later than 31 October 2008, replace the hoist cable assembly with a serviceable unit.

Note:  EASA Emergency AD 2008-0142-E refers.

Compliance:

1.    Before further flight after 1 August 2008.

2.    Within 30 days after 1 August 2008.

3.    As specified in Requirement 3.

This Airworthiness Directive becomes effective on 1 August 2008.

Background: Agusta has recently published Revision 6 for Chapter 4 of the AB412 Maintenance Manual to introduce a retirement life limit for the cables installed on certain hoists.  In addition, Agusta has introduced the concept of “hoist lift” to be used for the determination of cable life, instead of the term “hoist cycle”.  The newly established retirement life is 1,500 accumulated hoist lifts or 4 years, whichever occurs first.

David Villiers
Delegate of the Civil Aviation Safety Authority

31 July 2008