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/RB211/11 Fuel Metering Valve Torque Motor Test 9/90 Applicability: All Rolls Royce RB 211-524G2-19/11, RB 211-524G2-19/15, RB 211-524G3-19/15, RB 211-524H2-19/15 AND RB 211-524H2-19/15 engines with fuel metering units (FMU) at pre S.B. 73-9282 (increased rating inlet filter mesh) status. Note: Lucas SB 600-73-6726 also refers. Requirement: Perform an on wing test to determine the serviceability of the fuel metering unit metering torque valve motor in accordance with Rolls Royce Service Bulletin RB.211-71-9270. Note: Compliance with this SB has been made mandatory by the UK CAA. Compliance: Initially, prior to 6 October 1990, and thereafter at intervals not exceeding 350 hours time in service. Background: There have been three recent reports of uncommanded engine run down to a sub-idle condition, one during cruise, one during descent, and one during taxi. All three failures have been attributed to a virtual blockage of the fuel metering valve torque motor inlet filter. To reduce the possibility of uncommanded engine run down, a fuel metering unit metering valve torque motor test is required to be carried out in accordance with this AD.