COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Rolls Royce Turbine Engines - RB211 Series AD/RB211/3 Amdt 2 Speed and Temperature Governing System 10/99 Applicability: RB211 engines as detailed in Rolls Royce Service Bulletin Number RB.211-73-4305 Revision 6. Requirement: To identify possible dormant failures within the speed and temperature governing system which may prevent response of the governing system to an overspeed; carry out a maintenance test of the speed governing system as described in the Aircraft Maintenance Manual, Chapter 73-21-00, Adjustment/Test. Rolls Royce Service Bulletin Number RB.211-73-4305 Revision 6 refers. Note: The requirements of Rolls Royce Service Bulletin Number RB.211-73-4305 Revision 6 have been declared mandatory by the CAA (UK). Compliance: Unless previously accomplished; within 750 hours time in service from the effective date of this directive and thereafter at intervals not to exceed 750 hours time in service. This Amendment becomes effective on 7 October 1999. Background: This directive was originally issued to require a periodic test of the speed and temperature governing system. The requirement reflected advice of a dormant failure could result in the governing system not responding to an overspeed or over temperature condition. Amendment 1 was issued in June 1982 to include the RB211-524D4-19 model. This amendment reflects the manufacturer's latest revision to the requirement document. The revision, in part, deletes the requirement to carry out a periodic test of the temperature governing function. Automatic control of the temperature channel is no longer considered essential for the safe operation of the engine. Amendment 1 of this Airworthiness Directive became effective 30 June 1982. The original issue of this Airworthiness Directive became effective on 31 January 1982.