ALERT SERVICE BULLETIN 206L-08-150

M250--B17F Series TP CEB A--72--2091 ENGINE, TURBINE ASSEMBLY -- STEADY--STATE OPERATION AVOIDANCE RANGE LIMIT 1. PLANNING INFORMATION A. Effectivity (1) Engines All Rolls-Royce Model M250--C20, --C20R, --B17 and --B17F Series engines are affected by this Commercial Engine Bulletin (CEB). (2) Spares -- Not affected B. Reason This Alert CEB has been released by Rolls--Royce to heighten awareness of the N2 speed avoidance range for Series II engines. It is required to observe the speed avoidance range and operating procedures to minimize the possibility of power turbine failure.The required engine N2 speed avoidance range is dependent upon the part number of the Power Turbine Wheel in service, engine model, and the OEM application in which the engine is installed. Part numbers of the 3rd--stage and 4th--stage Turbine Wheels in service, engine models, and the OEM applications affected are as follows: (1) Enhanced Power Turbine Fitted with P/N 23065818 3rd--stage Turbine Wheel and P/N 23055944 4th--stage Turbine Wheel or P/N M250--10445 4th--stage Turbine Wheel. For normal operation, all OEM applications are affected. The engine N2 speed avoidance range is dependent upon the part number of the 4th--stage Turbine Wheel installed and the engine model. (2) Non--Enhanced Power Turbine Fitted with P/N 23065833 3rd--stage Turbine Wheel. For normal operation, the following OEM applications are affected: Agusta A109 (all models), Soloy B206L/R and Eurocopter BO105 (all models). In addition, this speed avoidance range is applicable during One--Engine--Inoperative (OEI) operation of multi--engine aircraft. P/N 23065833 wheel is no longer manufactured and so alternative options for replacement of the wheel at next turbine overhaul are discussed in paragraph 2.C.(1)(d). (3) Non--Enhanced Power Turbine Fitted with P/N 23001967 3rd--stage Turbine Wheel and P/N 6853279 4th--stage Turbine Wheel. No N2 speed avoidance range is required for any OEM application. P/N 23001967 and P/N 6853279 wheels are not affected by this CEB and are mentioned only for completeness. COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 2 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 C. Description This CEB requires Operators to avoid engine N2 steady--state operation in the speed avoidance range as specified by 3rd--stage turbine wheel part number and 4th--stage turbine wheel part number in the following wording and charts. Transition through the speed range is to be accomplished as expediently as possible. In autorotation, with N2 split from NR and throttle in the Ground Idle position, unrestricted operation within the speed avoidance range is permitted. Transient operation in the speed avoidance range during recovery from autorotation is permitted. NOTE: Transient Operation is defined as no dwell at an N2 speed of more than a 1 second duration. D. Approval Technical aspects are FAA approved. E. Compliance Compliance Code 1: To be complied with immediately. F. Interchangeability -- Not affected G. Material Availability PART NUMBER QTY/ENGINE NAME MODEL 23065833 1 Third--stage, Turbine Wheel C20 Series, C20R Series 23065818 1 Third--stage, Turbine Wheel B17 Series, B17F Series, C20 Series, C20R Series, C20S 23055944 1 Fourth--stage, Turbine Wheel B17 Series, B17F Series, C20 Series, C20R Series, C20S M250--10445 1 Fourth--stage, Turbine Wheel B17 Series, B17F Series, C20 Series, C20R Series, C20S H. Tooling -- Not affected I. Weight and Balance -- Not affected J. Electrical Load Data -- Not affected Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 3 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 K. References (1) 10W2 Operation and Maintenance Manual, Turboshaft Models, M250--C20, --C20B, --C20F, --C20J, --C20S, --C20W (OMM). (2) 10W3 Overhaul Manual, Turboshaft Models M250--C20, --C20B, --C20F, --C20J, --C20S, --C20W (O/H). (3) 10W4 Illustrated Parts Catalog, Turboshaft Models M250--C20, --C20B, --C20C, --C20F, --C20J, --C20S, --C20W (IPC). (4) 11W2 Operation and Maintenance Manual, Turboprop Models M250--B17, --B17B, --B17C, --B17D, --B17E (OMM). (5) 11W3 Overhaul Manual, Turboprop Models M250--B17, --B17B, --B17C, --B17D, --B17E (O/H). (6) 11W4 Illustrated Parts Catalog, Turboprop Models M250--B17, --B17B, --B17C, --B17D, --B17E (IPC). (7) CSP21007 Operation and Maintenance Manual, Turboshaft Models M250--C20R, --C20R/1, --C20R/2, --C20R/4 (OMM). (8) GTP5232--3 Overhaul Manual, Turboshaft Models M250--C20R, --C20R/1, --C20R/2, --C20R/4 (O/H). (9) CSP23007 Illustrated Parts Catalog, Turboshaft Models M250--C20R, --C20R/1, --C20R/2, --C20R/4 (IPC). (10) CSP21008 Operation and Maintenance Manual, Turboprop Models M250--B17F, --B17F/1, --B17F/2 (OMM). (11) GTP5243--3 Overhaul Manual, Turboprop Models M250--B17F, --B17F/1, --B17F/2 (O/H). (12) CSP23008 Illustrated Parts Catalog, Turboprop Models M250--B17F, --B17F/1, --B17F/2 (IPC). L. Prerequisites -- None 2. ACCOMPLISHMENT INSTRUCTIONS A. Identification of Wheel and Action Required. The part number of the power turbine wheels installed in a Model M250 Series II engine is recorded in the engine logbook, Turbine Assembly, Assembly Record, Part V. The part number must be used to identify the appropriate action described in paragraph 2.B. or 2.C. The flowchart that follows is included as a simple guide to help identify the appropriate action for each wheel type. Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 4 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 Start Check wheel P/N’s given in engine Log book. If P/N 23065818 and P/N 23055944 Installed in turbo- shaft or turboprop? If P/N 23065833 Applies only to wheels used in A109, Soloy B206L and BO105 applications and during OEI operation of multi-- engine aircraft. No Yes Replace Upgrade Then ACTION -- B Speed Avoid Range until next turbine overhaul. See TABLE 1 for Speed Avoid Range for A109, Soloy B206L and BO105. Upgrade to Enhanced Power Turbine requires new 3rd--stage wheel P/N 23065818 and new 4th--stage wheel P/N 23055944 or M250--10445,and nozzles. At next turbine overhaul either replace with P/N 23001967 or upgrade to Enhanced Power Turbine. Then Action A.(2) 75--88% N2 Speed Avoid Range. Turboprop Turboshaft If P/N 23065818 and M250--10445 Applies to all OEM applications. Return to Start. Then Action A.(1) Avoid Range. 71--88% N2 Speed No action required. Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 5 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 B. Action A (1) This action is applicable to all Rolls--Royce M250--C20 Series (except M250--C20S) and --C20R Series Turboshaft Engines used in all Turboshaft OEM applications fitted with enhanced power turbine wheels P/N 23065818 3rd--stage Turbine Wheel and P/N 23055944 4th--stage Turbine Wheel. A 71% to 88% engine N2 steady--state speed avoidance range is required for all operational practices. Rolls--Royce must be consulted for additional guidance on the speed avoidance range for any OEM application that has a potential steady--state operating speed below 89% N2. NOTE: Transient operation only is permitted in the speed avoidance range. Any exposure in the speed avoidance range must be minimized as much as possible. This action applies to all flight and ground maintenance (including track and balance) operational practices. Operation within the speed avoidance range is permitted for preflight and postflight checks specified in OEM flight manuals. NOTE: In autorotation, with N2 split from NR and throttle in the Ground Idle position, unrestricted operation within the speed avoidance range is permitted. Transient operation in the speed avoidance range during recovery from autorotation is permitted. NOTE: Transient Operation is defined as no dwell at an N2 speed of more than a one second duration. (2) This action is applicable to all Rolls--Royce M250--B17 Series, --B17F Series and --C20S Turboprop Engines used in all Turboprop OEM applications fitted with enhanced power turbine wheels P/N 23065818 3rd--stage Turbine Wheel and P/N 23055944 4th--stage Turbine Wheel. This action is also applicable to all Rolls--Royce M250 Series II Engines used in all OEM applications fitted with enhanced power turbine wheels P/N 23065818 3rd--stage Turbine Wheel and P/N M250--10445 4th--stage Turbine Wheel. A 75% to 88% engine N2 steady--state speed avoidance range is required for all operational practices. Rolls--Royce must be consulted for additional guidance on the speed avoidance range for any OEM application that has a potential steady--state operating speed below 89% N2. NOTE: Transient operation only is permitted in the speed avoidance range. Any exposure in the speed avoidance range must be minimized as much as possible. This action applies to all flight and ground maintenance (including track and balance) operational practices. Operation within the speed avoidance range is permitted for preflight and postflight checks specified in OEM flight manuals. NOTE: For turboshaft engines in autorotation, with N2 split from NR and throttle in the Ground Idle position, unrestricted operation within the speed avoidance range is permitted. Transient operation in the speed avoidance range during recovery from autorotation is permitted. NOTE: Transient Operation is defined as no dwell at an N2 speed of more than a one second duration. Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 6 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 C. Action B -- Non--Enhanced Power Turbine Fitted with P/N 23065833 3rd--stage Turbine Wheel. (1) For normal engine operation, this action is required only for Model 250 Series II Engines used in the following OEM applications: Agusta A109 (all models), Soloy B206L/R and Eurocopter BO105 (all models). This action is required only until the next turbine overhaul at which time the 3rd--stage Turbine Wheel must be removed from service. All other single--engine OEM applications with 3rd--stage Turbine Wheel P/N 23065833 installed do not require this action. Two options are available to satisfy this action (paragraph 2.C.(1)(a) or 2.C.(1)(b)). Only one option need be implemented: (a) Conduct N2 Indication System Calibration Check. A narrower N2 speed avoidance range is required if a calibration check on the N2 indication system can be performed to zero out any error. If this can be accomplished, then the required engine N2 speed avoidance range is 87% to 95% N2. If this cannot be accomplished, then refer to paragraph 2.C.(1)(b) for the required expanded engine N2 speed avoidance range that includes an appropriate allowance for the N2 indication system accuracy of each OEM application affected. (b) N2 Speed Avoidance Range. The allowable engine N2 steady--state operating speed is a function of the engine N2 speed indication system error. The required engine N2 speed avoidance range is documented in TABLE 1 for the affected OEM applications, and applies to both flight and ground maintenance (including track and balance) operational practices. Operation within the speed avoidance range is permitted for preflight and postflight checks specified in OEM flight manuals. NOTE: In autorotation, with N2 split from NR and throttle in the Ground Idle position, unrestricted operation within the speed avoidance range is permitted. Transient operation in the speed avoidance range during recovery from autorotation is permitted. TABLE 1 OEM Application Specific Speed Avoid Range OEM Aircraft Speed Avoidance Range (% N2) A109 85.0--97.0 Soloy B206L 84.5--97.5 BO105 86.5--95.5 NOTE: The operation restriction in the speed avoidance range applies to sustained engine N2 steady--state engine operation. It does not apply to transient operation passing through this speed range. Transient Operation is defined as no dwell at an N2 speed of more than a one second duration. (c) N2 Gage Indication System Calibration or N2 Speed Avoidance Range Not Implemented. If the N2 Gage Indication System or the N2 Speed Avoidance Range cannot be implemented for any reason, then the turbine must be sent to an authorized overhaul facility for removal of the 3rd stage Turbine Wheel P/N 23065833 and a replacement wheel as discussed in paragraph 2.C.(1)(d) installed. Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce COMMERCIAL ENGINE BULLETIN EXPORT CONTROLLED ALERT Page 7 of 7 December 22, 2006 Revision 6 April 12, 2018 E2006, 2018 Rolls--Royce Corporation M250--C20 Series CEB A--1400 M250--C20R Series CEB A--72--4095 M250--B17 Series TP CEB A--1343 M250--B17F Series TP CEB A--72--2091 (d) Replacement Wheel Options at Turbine Overhaul. At the next scheduled turbine overhaul, 3rd--stage Turbine Wheel P/N 23065833 must be removed from service and scrapped. Replacement options are a direct swap with P/N 23001967 3rd--stage Turbine Wheel or to upgrade to the Enhanced Power Turbine design that uses P/N 23065818 3rd--stage Turbine Wheel. The upgrade to the Enhanced Power Turbine requires new 3rd-- and 4th--stage Turbine Wheels and nozzles. (e) Re--use of Engines Fitted with P/N 23065833 3rd--stage Turbine Wheels Prohibited. Engines fitted with 3rd--stage Turbine Wheel P/N 23065833 that have been used in one or more of the affected OEM applications (A109 (all models), Soloy B206L/R, BO105 (all models)), must not be used in other OEM application (including non--affected OEM applications) without first removing the turbine unit from service and scrapping the 3rd--stage Turbine Wheel. (2) For OEI operation, this action is required for Model 250 Series II engines used in multi--engine aircraft. A mandatory 87% to 95% engine N2 steady--state speed avoidance range is required. NOTE: The operation restriction in the speed avoidance range applies to sustained engine N2 steady--state engine operation. It does not apply to transient operation passing through this speed range. Transient Operation is defined as no dwell at an N2 speed of more than a one second duration. If the N2 speed avoidance range cannot be implemented during OEI operation, the turbine unit of the engine operating during the event must be immediately removed from service following the event and the turbine unit sent to an authorized repair facility for the 3rd--stage turbine wheel to be scrapped. Replacement 3rd--stage turbine wheel options are discussed in paragraph 2.C.(1).(d). 3. MATERIAL INFORMATION -- Not applicable CUSTOMER SUPPORT ROLLS-ROYCE Rolls-Royce Proprietary Data – Uncontrolled Printed Copy Rolls-Royce Proprietary Data – Uncontrolled Printed Copy