Document ID: chunk:federal_register_of_legislation:F2006B08688:body:0
Version: federal_register_of_legislation:F2006B08688
Segment Type: other
Provision Reference: 
Character Range: 0–851

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
 SCHEDULE OF AIRWORTHINESS DIRECTIVES

 General Electric Turbine Engines - CT7 Series

AD/CT7/4 Turbine Rotor Discs 8/90

 Applicability: CT7-5A2/7A.

            Requirement: Action in accordance with General Electric Alert SB (CT7-TP series) A72-228 and A72-229.

 Compliance: Effective from 9 August 1990.

            Background:  During a walnut shell-cleaning process at an overhaul facility, a number of stages 1 and 2 gas generator turbine rotor discs and stages 3 and 4 power turbine rotor discs may have been shotpeened inadvertently by walnut shells contaminated with steel shot. As a result, these parts may have a reduced low cycle fatigue (LCF) life. The Service Bulletins nominate the suspect parts and new life cycle limits.