AD/AL 250/3 Oil Filter By-Pass Valve Poppet Guide Replacement Cancelled (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/AL 250/3.

Allison Turbine Engines - 250 Series

AD/AL 250/3 Oil Filter By-Pass Valve
Poppet Guide - Replacement 6/2009

Requirement:

CANCELLED.

This AD is cancelled on 4 June 2009.

Background:

This unique Australian AD raised in 1968 against Allison Commercial Engine Bulletin (CEB) 250 CEB-31 required a modification by replacing the oil filter by-pass valve poppet guide with one that features a pilot diameter which has a close fit with the inside diameter of an installed retaining ring, to ensure that the ring is fully installed to prevent retaining ring becoming dislodged causing loss of engine and torquemeter oil pressure.

Compliance was:  Before installation in an aircraft following next overhaul completed after 13 June 1968.

This AD has been sufficiently promulgated for the affected engines to have been modified by now; therefore this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 April 2009