AD 2004-13-11 Airworthiness Directives; Rolls-Royce plc RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 884B-17, Trent 892-17, Trent 892B-17, and Trent 895-17 Series Turbofan Engines

This AD applies to Rolls-Royce plc (RR) RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 series turbofan engines that have not incorporated RR SB No. RB.211-72-D495, dated February 7, 2003. These engines are installed on, but not limited to, Boeing 777 series airplanes.

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. Initial Visual Inspection of the IP Turbine Shaft and IP Compressor Stubshaft (f) At the next accessibility of the IP turbine shaft, not to exceed the later of 4,500 cycles-since-new (CSN) or 100 cycles after the effective date of this AD on the IP turbine shaft, do the following: (1) Inspect the IP turbine shaft splines for wear. Information on inspecting IP turbine shaft splines can be found in RR Mandatory Service Bulletin (MSB) No. RB.211-72-D339, Revision 2, dated June 20, 2003. (2) If the IP turbine shaft spline wear measured in paragraph (f)(1) of this AD is greater than 0.005 inch, remove the IP turbine shaft from service. (3) If the IP turbine shaft spline wear measured in paragraph (f)(1) of this AD is greater than 0.001 inch, inspect IP compressor stubshaft splines for wear. Information on inspecting IP compressor stubshaft splines can be found in RR MSB No. RB.211-72-D339, Revision 2, dated June 20, 2003. (4) If the IP compressor stubshaft spline wear measured in paragraph (f)(3) of this AD is greater than 0.005 inch, remove the IP compressor stubshaft from service. (5) For the purposes of this AD, accessibility of the IP turbine shaft is defined as removal of the IP turbine module from the engine. Repetitive Visual Inspections of the IP Turbine Shaft and IP Compressor Stubshaft (g) Perform repetitive visual inspections of the IP turbine shaft and IP compressor stubshaft using the procedures specified in paragraph (f)(1) through (f)(4) of this AD, at each accessibility, not to exceed the applicable repetitive inspection intervals in the following Table 1: Table 1.—Repetitive Visual Inspection Intervals Results of last inspection Reinspection interval (1) If wear was less than 0.001 inch on IPT shaft splines and IPC stubshaft splines Reinspect within 4,500 cycles-since-last visual inspection (CSLI) of the IPT shaft splines. (2) If wear was 0.001 inch or greater on IPT shaft splines or on the IPC stubshaft splines Reinspect within 2,000 CSLI of the IPT shaft splines or IPC stubshaft, whichever occurs first. (3) If an ultrasonic measurement of wear was less than 0.013 inch Reinspect within 3,000 cycles since last ultrasonic inspection. Optional Initial Ultrasonic Inspection of the IPT Shaft and IPC Stubshaft (h) As an option to the initial visual inspection specified in paragraph (f) of this AD, do the following: (1) At the later of 4,400 CSN or 100 cycles after the effective date of this AD on the IPT shaft, ultrasonically inspect the IP compressor stubshaft. Information on the ultrasonic inspection can be found in RR MSB No. RB.211-72-D339, Revision 2, dated June 20, 2003. (2) If wear is greater than 0.013 inch, remove engine from service within an additional 100 cycles-in-service. Optional Repetitive Ultrasonic Inspections of the IP Turbine Shaft and IP Compressor Stubshaft (i) As an option to the repetitive visual inspections specified in paragraph (g) of this AD, do the following: (1) Ultrasonically inspect the IP compressor stubshaft, using the repetitive inspection intervals in Table 2 of this AD. Information on the ultrasonic inspection can be found in RR MSB No. RB.211-72-D339, Revision 2, dated June 20, 2003. Table 2.—Repetitive Ultrasonic Inspection Intervals Results of last inspection Reinspection interval (i) If visually inspected wear was less than 0.001 inch on IPT shaft splines and IPC stubshaft splines Reinspect within 4,400 cycles-since-last visual inspection (CSLVI) of the IPT shaft splines. (ii) If visually inspected wear was 0.001 inch or greater on IPT shaft splines or on the IPC stubshaft splines Reinspect within 2,000 CSLVI of the IPT shaft splines or IPC stubshaft, whichever occurs first. (iii) If ultrasonically inspected wear was less than 0.013 inch Reinspect within 3,000 since last ultrasonic inspection. (2) If wear is greater than 0.013 inch, remove engine from service within an additional 100 cycles-in-service. Alternative Methods of

This AD results from reports of load-bearing spline flank wear of intermediate pressure (IP) compressor rear stubshaft and intermediate pressure (IP) turbine shaft, revealed at inspection during overhaul. We are issuing this AD to prevent the loss of drive between the IP turbine and the IP compressor, which could result in a turbine rotor overspeed condition, possible uncontained engine failure, and damage to the airplane.