AD/Bell 427/4 Hydraulic Solenoid Tee Fitting (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 427 Series Helicopters

AD/BELL 427/4 Hydraulic Solenoid Tee Fitting 5/2006

Applicability:

Bell Helicopter Textron Canada (BHTC) Model 427 helicopters S/N 56001 through 56031 and 58001 through 58002.

Requirement:

Replace the Tee fitting P/N AS1 003W060404 and tubes P/N 427-080-058-101,
427-080-003-101 with Union P/N AS 5230W0606, Tee fitting P/N NAS1763W060404 and tubes P/N 427-080-069-101, 427-080-068-101, as per instructions outlined in Alert Service Bulletin (ASB) 427-01-02 dated 20 August 2001, or later Transport Canada approved revisions.

Note:  Transport Canada AD CF-2000-11 refers.

Compliance:

Within 30 days after the effective date of this AD, unless previously accomplished.

This Airworthiness Directive becomes effective on 11 May 2006.

Background:

While performing a regular maintenance activity, there is a possibility of installing the existing Tee fitting (P/N AS1003W060404) in such a way that the hydraulic fluid flow will be significantly restricted.  To preclude this possibility, a new Tee fitting installation has been designed.

James Coyne
Delegate of the Civil Aviation Safety Authority

17 March 2006