COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Rolls Royce Turbine Engines - Tay Series AD/TAY/4 Fuel Flow Regulator Life Limit 7/99 Applicability: Rolls Royce Tay fuel flow regulators listed by serial number in RR Service Bulletin TAY-73-1459. Requirement: Remove from service applicable fuel flow regulators for rework as in Rolls Royce Service Bulletin TAY-73-1459. Note: UK CAA AD 002-01-99 also refers. Compliance: At a period not exceed 6500 hours time in service since new or last overhaul. This Airworthiness Directive becomes effective on 15 July 1999. Background: Rolls Royce has advised a number of fuel flow regulators in a foreign operator's fleet have been exposed to contaminated fuel. FFR drive gear failures have been attributed to using contaminated fuel. Limiting the time in service will prevent FFR failure due to excessive gear wear.