AD/B737/259 - Fail-Safe Straps of the Nose Cowl Engine Inlet Attach Ring (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.

Boeing 737 Series Aeroplanes AD/B737/259 Fail-Safe Straps of the Nose Cowl 13/2005 Engine Inlet Attach Ring

Applicability: Model 737-200 and -200C series aircraft, equipped with dB Partners Hush Kit having attach ring, part number 65ND-54301-1, installed in accordance with Supplemental Type Certificate (STC) SA5730NM. Requirement: Action in accordance with FAA AD 96-04-03 Amdt 39-9514.

Note: Nordam Service Bulletins SB 71-03, SB 71-03 Revision 1, and SB 71-04 Revision 1, or later FAA approved revisions, refer. Compliance: As specified in the Requirement document, with a revised effective date of 22 December 2005. This Airworthiness Directive becomes effective on 22 December 2005. Background: The FAA received reports of failure of reworked turbine blades, and subsequent failure of engine inlet attach ring. This Directive requires repetitive inspections to detect cracking of the attach ring of the nose cowl, until replacement with an improved attach ring that eliminates the need for repetitive inspections. The actions specified by this Directive are intended to prevent cracking of the attach ring of the nose cowl, which could result in separation of the nose cowl from the engine following failure of a turbine blade.