AD/Hu 369/108 Amdt 1 Tailboom Attachment (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/HU 369/108 and issues the following 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.

McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters

AD/HU 369/108 Amdt 1 Tailboom Attachment 7/2006 DM

Applicability:

Model 600N helicopters, with serial numbers RN003 through RN058, that have not been modified in the fuselage aft section to strengthen the tailboom attachments and longerons in accordance with MD Helicopters Technical Bulletins TB600N-007 or TB600N-007 Revision 1, or a later FAA approved revision.

Requirement:

Action in accordance with the technical requirements of FAA AD 2006-08-12 Amdt 39-14569.

Note:  MD Helicopters Service Bulletins SB600N-036, SB600N-039, and
SB600N-043, or later FAA approved revision, refer.

Compliance:

As specified in the Requirement document, with a revised effective date of
18 May 2006.

This Amendment becomes effective on 18 May 2006.

Background:

The FAA received a report of a cracked tailboom attachment bolt on an MD 600N helicopter.  Further inspection revealed cracking on bolts and attachments on several other helicopters.  This condition, if not corrected, could result in failure of a tailboom attachment, loss of the tailboom, and subsequent loss of control of the helicopter.

Amendment 1 is issued in response to a new FAA AD, which requires the same actions as the original issue of this Directive, but also requires additional inspection holes in the aft fuselage skin panels and inspection of the upper and lower tailboom attachment fittings, the upper longerons, and the angles and nutplates for cracks.  It also requires eventual replacement of the upper right tailboom attachment fitting.

David Villiers
Delegate of the Civil Aviation Safety Authority

16 May 2006