CF34 TURBOFAN ENGINE MAINTENANCE MANUAL LIFE LIMITS OF ROTATING ENGINE PARTS

Transcription

1 LIFE LIMITS OF ROTATING ENGINE PARTS 1. General. A. The FAA has approved service life-limit cycles (Airworthiness Limitations) for rotating parts installed in the CF34-1A/-3A/-3A2 turbofan engines. B. This chapter identifies engine parts that are life-limited as a result of exposures to operating cycles or hours. It explains how to calculate life-limit cycles to allow the operator to determine the number of cycles at which a part must be removed from service. C. Rotating parts of all turbine engines have some type of service limits. Critical rotating parts are those parts whose sudden failure could threaten the structural integrity of the engine. These parts, when subjected to large repeated and/or alternating stresses, can fail through fatigue. The material properties of a part are depleted by fatigue as a function of the number of stress cycles the part experiences. Stress cycles of turbine engine rotating parts result from the transients of engine speed and temperatures occurring during normal engine operation. Therefore, the life-limit cycles provide the operator with a means of tracking the useful service life of a part so that the part can be removed from service before possible fatigue failure. These life-limits are usually expressed in terms of cycles, and can be related almost directly to the number of stress cycles that occur during engine operation. It is for this reason that the limits are in terms of cycles. D. Life limits of the critical rotating parts are established through analysis and testing. Accumulated cycles are compared to the life limits to determine if the affected hardware is still serviceable. No component must be permitted to remain in service beyond its life-limit cycles. Refer to paragraph 2.A. for the definition of a cycle. E. There are two methods (refer to paragraph 2.E.) available for counting life-limit cycles; a primary method and an alternate method: (1) The primary method is simpler than the alternate method, and is appropriate for most aircraft operators. NOTE: High-utilization operators are defined as operators whose mission requirements generate higher than normal touch-and-go landings, missed approaches, or landings without an engine shutdown. (2) The alternate method is recommended for high-utilization operators because it provides cycle counts more representative of their type of aircraft usage TIME LIMITS Page 801 Sep 30/98

2 (3) The overall cycle counts using the alternate method will be lower than the primary method cycle counts because the alternate method differentiates between stresses experienced in different mission operations. The primary method does not make this distinction as it is of little benefit in general aircraft use. F. GE Aircraft Engines has completed extensive testing of the engine and its components to provide the basis for the establishment of life limit cycles. GE Aircraft Engines will continue testing and will revise this chapter when life-limit changes are justified and when substantiating data has been approved by the FAA. G. Life-limited parts must be removed from service before or as soon as the life-limit of that part (as established by this chapter) has been reached. CAUTION: CERTAIN ROTATING PARTS ARE LIFE-LIMITED BASED ON THE SPECIFIC APPLICATION FOR WHICH THE PART IS INTENDED. IN SOME CASES, DIFFERENT LIFE LIMITS HAVE BEEN ESTABLISHED F0R IDENTICAL GE LIFE-LIMITED PARTS FOR DIFFERENT APPLICATIONS (FOR EAMPLE, CF34-3A1 VS CF34-3B). ACCORDINGLY, THE FOLLOWING PRECAUTIONS AND GUIDELINES MUST BE OBSERVED: USED LIFE-LIMITED PARTS MUST NOT BE RE-USED, UNLESS THE HISTORY OF THAT PART IS KNOWN. THIS CHAPTER CONTAINS INFORMATION FOR DETERMINING EQUIVALENT ACCUMULATED CYCLES VS THE APPLICATION. IF THE APPLICATIONS IN WHICH THE PART HAS OPERATED AND THE ACCUMULATED TOTAL NUMBER OF CYCLES ARE KNOWN, BUT THE NUMBER OF CYCLES OPERATED IN EACH APPLICATION ARE NOT KNOWN, THEN THE LOWEST LIFE LIMIT FOR A GIVEN PART MUST BE APPLIED (REFER TO PARAGRAPH 2.B, METHOD II). IT IS THE RESPONSIBILITY OF THE OPERATOR TO MAINTAIN ACCURATE RECORDS OF THE PART OPERATION. 2. Requirements. A. Definitions. A cycle is defined as a flight consisting of an engine start, takeoff, and landing. Use of thrust reverser is not included in this cycle count. Engine starts and shutdowns for operational checks, ground maintenance, and taxiing do not count against life-limit cycles, unless the engine is operated at takeoff fan speed. In that case, it counts as one cycle. Other operational procedures that affect the life-limit cycles of rotating parts are counted as follows: (1) An air start is considered one cycle on rotating parts TIME LIMITS Page 802 Sep 30/98

3 (2) When the thrust reverser is used and the throttle is advanced beyond 70% N2, 1/6 cycle is added to the cycle count of each rotating part. When the thrust reverser is used, but the throttle is not advanced beyond 70% N2, no additional cycles are added. (3) Whenever the throttle is used to set APR power, 2 cycles are added to the cycle count of each rotating part. (4) Each flight (takeoff and landing) counts as one cycle regardless of whether or not the engines are shut down prior to the next takeoff. (5) A touch-and-go landing counts as one cycle for each rotating part when using the primary cycle-counting method. (6) A go-around counts as 2 cycles for each rotating part if APR power is set using the throttle during the go-around. If APR power is not set, the go-around counts as 1 cycle for each rotating part. This applies for both the primary and the alternate cycle-counting methods. (7) If the alternate cycle-counting method is used, additional cycle counting must be done. For each touch-and-go landing and for each landing followed by a takeoff with no shutdown, record and calculate these events as follows: (a) The engine is divided into three sections for cyclic record keeping purposes. Maintain a separate cycle count for each of the following three sections: Section Components in Section Cycle Count for Touch-and-Go, or Landing With No Shutdown 1 Fan, Compressor, and all Low-Pressure Turbine (LPT) Life-Limited parts, except the Stage 4 Disk 2 All High-Pressure Turbine Life-Limited parts LPT Stage 4 Disk TIME LIMITS Page 803 Sep 30/98

4 (b) In addition to the cycle counts calculated in step (a), also count the following cycles for each of the three sections (refer to Sample Calculations in paragraph E, step (3)(b) for an example): ONE CYCLE PER FLIGHT FOR THE NORMAL MISSION. ONE CYCLE PER AIR START. ONE-SITH CYCLE (0.167) EACH TIME THE THRUST REVERSER IS ACTIVATED ABOVE 70% N2. TWO CYCLES EACH TIME THE THROTTLE IS USED TO SET APR POWER. B. Calculating Cycle Count For Common CF34 Engine Parts That Are Transferred Between Different CF34 Engine Models. (1) The different CF34 engine models have a number of life-limited parts that are common (have the same part number). Some of these common parts also have the same life limits when transferred between the different engine models. However, because the engine model series experience different operating environments, the life limits of some of the common parts may differ when used in different CF34 models. (2) When a common life-limited part is transferred from one CF34 engine model series to another, it will be necessary to calculate equivalent accumulated cycles for the part, taking into account the application (engine model) in which the part has operated, if the life of the part differs between engine models. All applicable information should be entered into the CF34 common life-limited parts tracking form (refer to table 801). The completed tracking form must be returned with the applicable common parts when those parts are transferred between different CF34 model series. The operator must get from GEAE, or from a GE authorized CF34 overhaul facility, the life limits for each CF34 model applicable to the components service history. (3) Two methods are available to establish the total life limit for life-limited parts that are used in more than one CF34 engine model: CAUTION: METHOD II MUST BE APPLIED, UNLESS THE NUMBER OF CYCLES OPERATED IN EACH ENGINE MODEL IS KNOWN AND DOCUMENTED. IT IS THE RESPONSIBILITY OF THE OPERATOR TO MAINTAIN ACCURATE RECORDS OF THE PART OPERATION. (a) Method I: If the number of cycles accumulated on one CF34 model is accurately known and documented, the fraction of life consumed can be calculated and used to determine the remaining cyclic life in a different CF34 model. First, calculate the fraction of life used for a part installed in a given CF34 model, then calculate the equivalent cycles since new (CSN) for the part installed in a different CF34 model; use this procedure: TIME LIMITS Page 804 Sep 30/98

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6 1 Calculate the fraction of life used for a part installed in initial CF34 model as follows: Fraction of life used = Cycles accumulated on CF34 model 1 LCF limit for CF34 model 1 2 Use this fraction to calculate the equivalent CSN on the part, if installed in another different CF34 model (model 2)as follows: Equivalent CSN for CF34 model 2 = Fraction of life used LCF limit for CF34 model 2 3 Determine the cycles remaining on the part installed in CF34 model 2 as follows: Cycles remaining CF34 model 2 = LCF limit for CF34 model 2 _ Equivalent CSN for CF34 model 2 4 Example 1: Consider a part with LCF limits in two different CF34 models as follows: CF34 Model 1 LCF limit = 15,000 cycles CF34 Model 2 LCF limit = 20,000 cycles The part accumulates cycles while installed in one CF34 model (model 1), and then will be installed in a different CF34 model (model 2). Calculate the equivalent CSN for the part installed in CF34 model 2, and determine how many LCF cycles remain, as follows: Fraction of life used = = 0.04 while installed in CF34 15,000 model TIME LIMITS Page 806 Sep 30/98

7 Equivalent CSN for CF34 model 2 Cycles remaining on the part installed in CF34 model 2 = 0.40 x 20,000 = 8,000 cycles = 20,000-8,000 = 12,000 cycles 5 Example 2: Consider a part with LCF limits in three different CF34 models as follows: Model 1 LCF limit = 12,000 cycles Model 2 LCF limit = 27,000 cycles Model 3 LCF limit = 20,000 cycles The part accumulates cycles while installed in one CF34 model (model 1), in addition to 4,000 cycles installed in a second CF34 model (model 2). The part is planned to be installed in a third CF34 model (model 3). Calculate the equivalent CSN for the part installed in CF34 model 3, and determine how many LCF cycles remain as follows: Fraction of life used = Cycles accumulated on CF34 model 1 LCF limit for model 1 + Cycles accumulated on CF34 model 2 LCF limit for model 2 Fraction of life used = + 4,000 = ,000 27,000 Equivalent CSN for model 3 = 0.65 x 20,000 = 13,000 cycles Cycles remaining for the part installed in CF34 model 3 = 20,000-13,000 = 7,000 cycles TIME LIMITS Page 807 Sep 30/98

8 (b) Method II: If the applications in which the part has operated and the total number of cycles accumulated are known, but the number of cycles operated in each application are not known, the lowest life limit for a given limit for a given part must be applied (as shown below) when calculating fraction of life consumed and cyclic life remaining. This method requires maintaining only records of the total number of cycles on the part in any CF34 model and the engine models in which the part has been used. 1 Calculate the fraction of life used for a part installed in initial CF34 model as follows: Fraction of life used = Total cycles accumulated Lowest published life of all models in which the part has operated 2 Use this fraction to calculate the equivalent CSN on the part, if installed in another different CF34 (model 2) as follows: Equivalent CSN for = Fraction of LCF limit for CF34 model 2 life used CF34 model 2 3 Determine the cycles remaining on the part installed in CF34 model 2 as follows: Cycles remaining = LCF limit for - Equivalent CSN for CF34 model 2 CF34 model 2 for CF34 model 2 4 Example 3: Consider a part with lcf limits in two different CF34 models as follows: CF34 Model 1 LCF limit = 15,000 cycles CF34 Model 2 LCF limit = 20,000 cycles The part has accumulated 5,000 cycles total while installed for some period of time on CF34 model 1, and for some period of time on CF34 model 2. The part will now be installed in CF34 model 2. Calculate the equivalent CSN and cycles that remain for the part installed in CF34 model 2. The lowest published life on the part (15,000 cycles) must be applied in the calculations because it is not known exactly how many cycles the part accumulated while installed in each engine model TIME LIMITS Page 808 Sep 30/98

9 C. Affected Components. Fraction of life used = Total cycles accumulated Lowest published life Fraction of life used = 5,000 = ,000 Equivalent CSN = ,000 = cycles for CF34 model 2 Cycles remaining on the part installed = 20,000-6,600 = 13,400 cycles in CF34 model 2 CAUTION: THE LIFE-LIMITED PARTS DEFINED IN THIS SECTION MUST NOT BE OPERATED BEYOND THE ESTABLISHED LIMITS. The engine components that are life-limited by this section are the following: Fan Rotor Components (refer to ). Compressor Rotor Components (refer to ). High-Pressure Turbine Rotor Components (refer to ). Low-Pressure Turbine Rotor Components (refer to ). Additional Life Limits (Non-LCF) (refer to ). D. Cycles Recording. (1) The operator is responsible for maintaining an accurate record of cycles experienced during engine operation. The operator must also monitor the status of the parts to ensure that none of the parts listed in paragraph C exceed the established life-limit cycles. (2) The CF34 Turbofan Engine Service Record book provides forms for recording the cycle history of the engine. (3) The operator and/or the Service or Overhaul Facility is responsible for making appropriate engine logbook entries to reflect changes in components. E. Sample Calculations for Primary and Alternate Life-Cycle Counting Methods. (1) Chapters through provide cycle limits which must be used to establish the continued serviceability of components. Step (2) shows an example of the primary life-cycle counting method, and step (3) shows an example of the alternate life-cycle counting method TIME LIMITS Page 809 Sep 30/98

10 (2) Examples of primary life-cycle counting method: (a) During a flight, the operator makes an air start on the right-hand engine, lands using the thrust reverser, and shuts down the engines. During the thrust reverser operation, the throttles are advanced above 70% N2. Cycle count right-hand engine: 1 1 1/6 2-1/6 Cycle count left-hand engine: 1 1/6 1-1/6 normal mission air start thrust reverser total normal mission thrust reverser total (b) The operator starts the engines, takes off, and lands using the thrust reverser followed by engine shutdown. The operator makes a second takeoff and landing using the thrust reverser, but does not shut down the engines. The operator then makes a third takeoff and landing without using the thrust reversers. The throttles were advanced beyond 70% N2 during the thrust reverser operation. The operator then makes a power assurance check at takeoff fan speed. Cycle count left-hand and right-hand engines: Flight plus Reverser and Shutdown 1-1/6 cycles Flight plus Reverser and no Shutdown 1-1/6 cycles Flight with No Reverser and Shutdown 1 cycle Power Assurance Check and Shutdown 1 cycle 4-1/3 cycles (3) Examples of alternate life-cycle counting method: (a) An operator starts the engines, takes off, and experiences a missed approach and a touch-and-go before landing and does not shut down the engines. The operator makes a second takeoff, and during the flight makes an air start on the right-hand engine. The operator then experiences two more missed approaches and another touch-and-go before making a second landing, and again does not shut down the engines. The operator then makes a third takeoff, and during the flight makes an air start on the left-hand engine. The operator lands using the thrust reversers with throttle advanced beyond 70% N2 and shuts down the engines TIME LIMITS Page 810 Sep 30/98

11 (b) Refer to paragraph A, steps (7)(a) and (7)(b) for the definitions, and calculate the cycle count as follows: CYCLE COUNT FOR EACH SECTION OF EACH ENGINE FOR EACH EVENT TIMES QUANTITY OF EVENTS IN THAT FLIGHT Section 1 Section 2 Section 3 One Takeoff Three Missed Approaches Two Touch-and-Go One Air Start Two Landings Followed by a Takeoff With No Shutdown Between One Thrust Reverser Application Above 70% N One Full Stop Landing with Shutdown Totals for this Flight TIME LIMITS Page 811 Sep 30/98

12 FAN ROTOR - LIFE-LIMITS 1. General. A. This section contains the FAA approved life-limits for the fan rotor components. B. The life limit is determined by the total number of flight cycles (refer to , TIME LIMITS for the definitions and calculations of cycles). C. The operator is responsible to make sure that the cycle-limited components are not used beyond their established cycle limits. CAUTION: IF YOU TRANSFER A LIFE-LIMITED PART FROM ONE CF34 MODEL TO ANOTHER CF34 MODEL, REFER TO , TIME LIMITS, PARAGRAPH 2.B, FOR CALCULATING CYCLE COUNT FOR COMMON CF34 ENGINE PARTS THAT ARE TRANSFERRED BETWEEN CF34 ENGINE MODELS. 2. Life Limits of Fan Rotor Components. Refer figure 801. LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 1 Fan Disk 5921T54G01 9,000 9, T01G03 13,200 13, T01G04 22,700 22, T01G05 22,700 22, T62G04 9,000 9, T62G05 9,000 9,000 *6078T00G01 9,000 9,000 *6078T57G02 *6078T57G T57G04 24,300 24, T57G05 24,300 24,300 2 Fan Forward Shaft 6017T63P04 38,280 38, T63P05 38,280 38, T51P01 15,000 15, T51P02 15,000 15, T51P03 15,000 15,000 3 Fan Drive Shaft 6036T78P02 15,000 15,000 * Fan disk can be reworked to 0 time after reaching current limits (refer to REI-13392, latest revision) at certified overhaul shops only TIME LIMITS Page 801 Sep 15/02 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

13 Fan Rotor - Life Limited Components Figure TIME LIMITS Page 802 Sep 30/98

14 COMPRESSOR ROTOR - LIFE LIMITS 1. General. A. This section contains the FAA-approved life limits for the compressor rotor components. B. The life limit is determined by the total number of flight cycles (refer to , TIME LIMITS for the definitions and the calculations of cycles). C. The operator is responsible to make sure that the cycle-limited components are not used beyond their cycle limits. CAUTION: IF YOU TRANSFER A LIFE-LIMITED PART FROM ONE CF34 MODEL TO ANOTHER CF34 MODEL, REFER TO , TIME LIMITS, PARAGRAPH 2.B, FOR CALCULATING CYCLE COUNT FOR COMMON CF34 ENGINE PARTS THAT ARE TRANSFERRED BETWEEN CF34 ENGINE MODELS. 2. Life Limits of Compressor Rotor Components. Refer to figure 801. LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 1 Stage 1 Disk 6040T79G T00G T00G02 2 Forward Shaft 5037T01P T01P04 3 Stage 2 Disk 6036T91P T91P02 4 Forward Spool 6036T75P T75P T56P T56P T56P T56P05 15,000 15,000 12,300 12,300 15,000 15,000 *12,000 27,000 27,000 15,000 15,000 11,740 11,740 15,000 15,000 *12,000 27,000 27,000 * Retire all forward spools PN 6078T56P01 at scheduled -hour overhaul or, if 6000-hour overhaul has been completed, at next exposure at or before 12,000 cycles TIME LIMITS Page 801 Sep 1/04 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

15 Compressor Rotor - Life Limited Components Figure TIME LIMITS Page 802 Sep 30/98

16 LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 5 Rear Spool 5087T46P T46P T83P T83P T02P01 6 Rear Shaft CDP Seal 22,000 22,000 22,000 22, T38P01 15,080 14,400 7 Rear Shaft 6016T83P T03P T03P T03P03 8 Stage 9 Disk 6016T43P T01P T01P T01P03 23,000 23,000 23,000 23,000 23,000 23, TIME LIMITS Page 803 Sep 1/04 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

17 HIGH-PRESSURE TURBINE ROTOR - LIFE LIMITS 1. General. A. This section contains the FAA-approved life limits for the highpressure turbine (HPT) rotor components. B. The life limit is determined by the total number of flight cycles (refer to , TIME LIMITS for the definitions and the calculations of cycles). C. The operator is responsible to make sure that the cycle-limited components are not used beyond their established cycle limits. CAUTION: IF YOU TRANSFER A LIFE-LIMITED PART FROM ONE CF34 MODEL TO ANOTHER CF34 MODEL, REFER TO , TIME LIMITS, PARAGRAPH 2.B, FOR CALCULATING CYCLE COUNT FOR COMMON CF34 ENGINE PARTS THAT ARE TRANSFERRED BETWEEN CF34 ENGINE MODELS. 2. Life Limits of High-Pressure Turbine Rotor Components. Refer to figure 801. LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 1 Seal, Balance Piston Air 5025T33P T56P T33P T58P T33P T33P T90P01 7,200 7,200 7,200 7,200 7,200 7,200 7,200 7,200 7,200 7,200 7,200 7,200 2 Shaft, HPT Rotor 6017T00P T00P T61P01 3 Plate, Stage 1 Front Cooling 3921T52P T15P T15P03 4 Disk, Stage 1 Turbine 6031T89P T50P T89P T89P T93P T93P02 4,358 4, TIME LIMITS Page 801 Sep 15/00

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19 LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 5 Plate, Stage 1 Aft Cooling 5041T70P01 Refer to Refer to T70P03 6 Plate, Stage 2 Rear Cooling 3921T54P T97P T97P03 7 Disk, Stage 2 Turbine 6031T90P T51P T90P T90P T94P T94P02 3,256 3,256 8 Plate, Stage 2 Front Cooling 3921T53P T29P T29P02 9 Coupling, Outer Torque 5041T67P T61P01 10 Coupling, Inner Torque 5041T66P T55P T02P01 NOTE: Cycle limits apply to all PN 5041T66P02 and PN 3921T55P01 inner torque couplings, except for the serial numbers listed below which are limited to 4,230 cycles. GAT3189B GAT3232F GAT3665H GAT5705B GAT3191B GAT3233F GAT3666H GAT5725B GAT3193B GAT3234F GAT3667H GAT5728B GAT3194B GAT3235F GAT3668H GAT8842G GAT3196B GAT3236F GAT3669H GAT8843G GAT3197B GAT3237F GAT3670H GAT8844G GAT3226F GAT3238F GAT3671H GAT8845G GAT3227F GAT3239F GAT3672H GAT8846G GAT3228F GAT3240F GAT3673H GAT8847G GAT3229F GAT3660H GAT3674H GAT8849G GAT3230F GAT3663H GAT3675H GAT8850G GAT3231F GAT3664H GAT3676H GAT8851G TIME LIMITS Page 803 Sep 15/00

20 LOW-PRESSURE TURBINE ROTOR - LIFE LIMITS 1. General. A. This section contains the FAA-approved life limits for the low-pressure turbine (LPT) rotor components. B. The life limit is determined by the total number of flight cycles (refer to , TIME LIMITS for the definitions and the calculations of cycles). C. The operator is responsible to make sure that the cycle-limited components are not used beyond their established cycle limits. CAUTION: IF YOU TRANSFER A LIFE-LIMITED PART FROM ONE CF34 MODEL TO ANOTHER CF34 MODEL, REFER TO , TIME LIMITS, PARAGRAPH 2.B, FOR CALCULATING CYCLE COUNT FOR COMMON CF34 ENGINE PARTS THAT ARE TRANSFERRED BETWEEN CF34 ENGINE MODELS. 2. Life Limits of Low-Pressure Turbine Rotor Components. Refer to figure 801. LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 1 Turbine Rear Shaft 6030T72P02 39,000 39, T19P01 38,280 34,490 2 Stage 3 Disk 5026T16P01 3,828 3, T14P T16P T91P01 15,000 15, T91P02 15,000 15,000 3 Stage 3 and 4 Seal 5023T59P02 33,000 29, T20P01 33,000 29,730 4 Stage 4 Disk 5026T17P02 4,330 4, T15P T17P T02P01 15,000 15, T02P03 17,000 17, T02P04 17,000 17,000 5 Stage 6 Disk 5023T45P03 8,816 7, T17P01 8,816 7, T45P04 8,816 7, T89P01 15,000 15, T89P03 15,000 15, TIME LIMITS Page 801 Sep 1/04 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

21 Low-Pressure Turbine Rotor - Life Limited Components Figure TIME LIMITS Page 802 Sep 15/99

22 LOCATION (REF. FIG. 801) COMPONENT NOMENCLATURE PART NUMBER CURRENTLY APPROVED LIFE-LIMIT CYCLES CF34-1A CF34-3A/-3A2 6 Stage 5 and 6 Seal 5023T64P02 33,000 29, T22P01 33,000 29,730 7 Stage 5 Disk 5024T53P01 5,830 5, T16P T53P T92P01 15,000 15, T92P02 15,000 15,000 8 Drive Cone 5023T40P01 15,000 15, T18P01 15,000 15, T40P03 15,000 15,000 9 Stage 4 and 5 Seal 5023T67P01 33,000 29, T21P01 33,000 29, TIME LIMITS Page 803 Sep 1/04 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

23 ADDITIONAL LIFE LIMITS (NON-LCF) 1. General. This section contains additional life limits for specific non-lcf components. 2. Life Limits. ITEM REQUIREMENT MAIMUM INTERVAL METHOD * * * * * FOR CF34-1A * * * * * HPT Stage 1 Blades: NOTE: Refer to SB (latest revision) for the maximum interval that apply to stage 1 blades that are installed in specific engine serial numbers. PN 6040T72P04 Replace 3000 hours Send the HPT rotor to PN 6040T72P07 Replace 3000 hours an authorized service PN 6040T72P08 Replace 3000 hours or overhaul facility. PN 6040T72P09 Replace 3000 hours PN 6040T72P10 Replace 3000 hours PN 6078T19 No Limit * * * * * FOR CF34-3A/3A2 * * * * * HPT Stage 1 Blades: PN 6040T72P07 Replace 1000 hours Send HPT rotor to an PN 6040T72P08 Replace 1000 hours authorized service or PN 6040T72P09 Replace 1000 hours overhaul facility. PN 6040T72P10 Replace 2000 hours PN 6078T19 No Limit TIME LIMITS Page 801 Sep 15/99

24 ITEM REQUIREMENT MAIMUM INTERVAL METHOD * * * * * FOR ALL * * * * * HPT Stage 1 Aft Cooling Plate PN 5041T70P01. HPT Stage 2 Studs (only when SB 72-5 is accomplished). Replace 3000 hours Send the HPT rotor to an authorized service or overhaul facility. Replace 6000 hours Send the HPT rotor to an authorized service or overhaul facility. No. 5 Bearing Carbon Seal Preformed Packing (KALREZ). Replace 3000 hours (refer to NOTE) Refer to , REMOVAL/INSTALLATION. NOTE: The No. 5 bearing carbon seal preformed packing must be replaced at the next 3000 hours (HSI) inspection, and then at every 3000 hours (HSI) thereafter. If Service Bulletin has been complied with, refer to , Table 803, item Q., NOTE 6 for instructions. Combustion Liner (PN 6063T15G01 and G04 only) (low-emission, Type I). Replace 750 cycles maximum (refer to NOTE) Refer to , REMOVAL/INSTALLATION. NOTE: Combustion liner PN 6063T15G01 and G04, that are installed in CF34-3A engines SN through (low-emission Type I), must be replaced between 600 and 750 cycles maximum until Service Bulletin (CF34) is complied with. HPT Stator Stage 2 Nozzle Retaining Ring Sector. Replace 3000 hours (refer to NOTE) Refer to , REMOVAL/INSTALLATION. NOTE: The stage 2 nozzle retaining ring sectors must be replaced at the next 3000 hours (HSI) inspection, and then at every 3000 hours (HSI) thereafter, unless Service Bulletin has been complied with. If Service Bulletin has been complied with, refer to , Table 803, item Q., NOTE 6 for instructions. GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page TIME LIMITS Page 802 Sep 1/04

25 LIST OF EFFECTIVE PAGES CHAPTER/ SECTION PAGE DATE CHAPTER/ SECTION PAGE DATE List of Effective Pages *1 Sep 1/04 Table of Contents 1 Sep 30/ thru 811 Sep 30/ Sep 15/ Sep 30/ *801 Sep 1/ Sep 30/98 *803 Sep 1/ thru 803 Sep 15/ *801 Sep 1/ Sep 15/99 *803 Sep 1/ Sep 15/99 *802 Sep 1/04 * Asterisk indicates pages added, changed, or deleted by this revision LIST OF EFFECTIVE PAGES Page 1 Sep 1/04 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.

26 TABLE OF CONTENTS SUBJECT LIFE LIMITS OF ENGINE ROTATING PARTS CHAPTER/ SECTION PAGE Life Limits of Engine Rotating Parts General 801 Requirements 802 Definitions 802 Calculating Cycle Count For Common CF34 Engine Parts That Are Transferred Between Different CF34 Engine Models. 804 Method I 804 Method II 808 Affected Components 809 Cycles Recording 809 Sample Calculations for Primary and Alternate Life-Cycle Counting Method 809 Primary Life-Cycle Counting Method 810 Alternate Life-Cycle Counting Method 810 Fan Rotor - Life Limits General 801 Life Limits of the Fan Rotor Components 801 Compressor Rotor - Life Limits General 801 Life Limits of the Compressor Rotor Components 802 High-Pressure Turbine Rotor - Life Limits General 801 Life Limits of the High-Pressure Turbine Rotor Components 801 Low-Pressure Turbine Rotor - Life Limits General 801 Life Limits of the Low-Pressure Rotor Components 801 Additional Life Limits (Non-LCF) General 801 Life Limits TABLE OF CONTENTS Page 1 Sep 30/98

27 SCHEDULED MAINTENANCE PROGRAM 1. General. A. This section contains the scheduled inspection checks for the CF34-1A/ -3A/-3A2 engines. B. The scheduled Inspection and Servicing Requirements (refer to table 801), or manufacturer's recommendations, consists of installed-engine repetitive visual and borescope inspections of the engine's external and internal components, specific maintenance checks and tasks, a performance trend monitoring program, and compliance with life limits as specified in Chapter/Section , compliance with all the manufacturer's Service Bulletins, as well as removal of the engine hot section for Hot Section Inspection (HSI). C. The scheduled inspection checks and servicing requirements set forth in this Chapter represents the plans and the recommendations by GE Aircraft Engines. The specified time intervals are based upon engines being operated at all times within approved operating limits and maintained in accordance with GE Aircraft Engines published instructions, including compliance with the recommended inspection intervals. D. The replacement intervals for life-limited parts (refer to Chapter/ Section ) shall take precedence over all maintenance actions contained in this Chapter. The inspection and maintenance intervals recommended herein are subject to the cycle life or hourly parts limits as described in Chapter/Section E. During the removal of engine components, and prior to the installation of any component, inspect all the components that are removed, or port ions of the components that are exposed. Inspect the components and the exposed areas in accordance with the published inspection criteria in the applicable sections in this manual. 2. Special Tools and Fixtures. The special tools and fixtures recommended by GE Aircraft Engines are listed in table 801. Equivalent substitutes can be used. TABLE 801. SPECIAL TOOLS AND FITURES TOOL NUMBER NOMENCLATURE Kit, Igniter Plug Gage (Unison Industries 7575 Baymeadows Way Jacksonville, FL USA CF34 ENGINE MAINTENANCE PROGRAM Page 801 Jun 30/97

28 3. Consumable Materials. The consumable materials listed in table 802 are recommended for use when doing scheduled maintenance procedures in this section. Equivalent substitutes can be used for listed items. TABLE 802. CONSUMABLE MATERIALS DESCRIPTION Oil, Penetrating (LPS-1) Oil, Penetrating (WD-40) MANUFACTURER LPS Research Lab, Inc Cotner Ave. Los Angeles, CA USA WD-40 Company P.O. Box San Diego, CA USA 4. Scheduled Inspection Checks. A. Preliminary Instructions. (1) The inspection time categories in table 803 are divided into six inspection intervals: Preflight or Postflight, 100-hour, 300- hour, 600-hour, 1200-hour, and 3000-hour inspection intervals. The checks in these intervals indicate the minimum inspection requirements for satisfactory inspection compliance. (2) Visually inspect the engine components for the appropriate Inspection Time Categories. (3) When the condition of an engine part can not be determined, refer to the inspection limits that apply to the individual part, in the applicable inspection table in this manual. (4) The oil filter must be inspected for contamination (refer to , INSPECTION) when: There has been an indication of oil impending bypass. The oil filter or the engine has reached its time category interval. The engine has been overhauled. B. Daily Checks (Preflight or Postflight). (1) Use a flashlight and visually inspect the engine inlet and exhaust areas (with the duct covers removed) for the conditions listed in table 803. (2) Inspect the ground surface area and any aircraft surfaces in the immediate vicinity of the engine inlets for foreign debris CF34 ENGINE MAINTENANCE PROGRAM Page 802 Jun 30/97

29 C. Periodic Inspections. (1) A thorough visual inspection of the engine is required at regular intervals and at complete overhaul scheduled for 6000 hours. (2) Borescope-inspect (refer to , INSPECTION) the compressor section, and clean (refer to , CLEANING) the compressor for performance recovery. (3) Visually inspect the engine components for the appropriate Inspec- tion Time Categories. D. Mid-Point (3000-Hour) Hot Section Inspection Interval. (1) Inspect the engine components listed in table 803 for the inspection time category at 3000 hours. Disassemble the engine to the extent that the combustion liner can be inspected (remove only the engine components necessary to access the combustion liner, and be sure that all turbine parts are matchmarked before you remove them). (2) After you remove the necessary airframe QEC parts, disassemble the engine in the sequence given in table 804 (refer to the paragraph titled "On-Aircraft Maintenance and Inspection of Hot Section" in , SPECIAL MAINTENANCE PRACTICES), for the procedures to inspect the Hot Section components. NOTE: The swirler assemblies are replaced when the combustion liner is reworked. The combustion liner PN 6052T10G01 (SN GGMDP906) and up, do not require rework. (3) Inspect the combustion liner, exposed carbon seals, and seal runners (refer to and , INSPECTION). (4) Do the following for these combustion liners: If the combustion liner is PN 6036T69G05 or PN 6052T10G01, return it to an authorized GE Aircraft Engines overhaul facility for rework. Do not return combustion liner PN 6052T10G01 with SN GGMDP906 and up (this liner does not require rework). Combustion liner PN 6036T69G05 must be reworked to PN 5921T51G01. Combustion liner PN 6052T10G01 (other than SN GGMDP906 and up) must be reworked to PN 5921T51G02. (5) Inspect the transition case for missing hard coat on the slots and inspect the transition outer liner for missing hard coat on the lugs (refer to , INSPECTION). Inspect the removed parts as required in the sections of this manual CF34 ENGINE MAINTENANCE PROGRAM Page 803 Jun 30/97

30 NOTE: It is not necessary to disassemble the major engine subassemblies (such as the LPT rotor and stator assemblies, or the HPT turbine rotor and stator assemblies). (6) Visually inspect all the exposed engine components and the exposed internal components that are visible, as required by the applica- ble inspection tables. (7) Clean the damaged Components; then repair them or replace them, if the condition indicates. (8) Re-assemble the engine according to the instructions in the appli- cable chapters referenced in table 804. (9) Functionally-check the engine (refer to the table titled "CHECKS REQUIRED AFTER MAINTENANCE" in , TESTING for the checks to be done); then, do an Engine Break-In Run (refer to , TESTING). TABLE 803. INSPECTION AND SERVICING REQUIREMENTS INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) A. Check the inlet duct for: (1) Deterioration, damage, and loose rivets. (2) Integrity of acoustical panels. (3) Presence of foreign objects. B. Check (refer to Note 1 at the end of this table) the external hoses and tubes, electrical connectors, ports, flanges, clamps, and brackets for: (1) Security. (2) Damage (visually) CF34 ENGINE MAINTENANCE PROGRAM Page 804 Jun 30/97

31 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (3) Evidence of leakage from external hoses or tubes. (4) Chafing (visually). C. Check (refer to Note 1 at the end of this table) under the cowl for evidence of leakage (fuel, oil, air) from: (1) Surfaces beneath the engine. (2) Engine surfaces and accessories. (3) Fuel heater.* * Remove the cap from the bleed air tube, and check for any evidence of fuel accumulation (not allowed). If fuel is found in the air tube, replace the fuel heater ( , REMOVAL/INSTALLATION). Re-install the cap; if the cap is silver-plated, torque the cap to lb in. ( N m); if the cap is not silver-plated, torque the cap to lb in. ( N m). D. Check the oil system for contamination as follows: NOTE: A leak check (refer to , TESTING) must be done after any component of the oil system is disconnected or removed. (1) Remove, inspect, and replace the oil filter element ( , INSPECTION) (also, refer to Note 1 at the end of this table) CF34 ENGINE MAINTENANCE PROGRAM Page 805 Jun 30/97

32 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) NOTE: The chip detector in the accessory gearbox (AGB) should be inspected when metal is found in the oil filter. If the AGB chip detector appears normal, or the metal in the oil filter is non-ferrous (not attracted by a magnet), then the Integrated Drive Generator (IDG) and the garlock seal should be removed to inspect the axis-bb drive bearing. Replace the oil filter after the first 100 hours of operation; then at 600 hours, and then every 600 hours thereafter. (2) Do a continuity check of all the magnetic chip detectors (refer to , INSPECTION). If the continuity check fails, inspect the chip detectors for metallic particles (refer to , INSPECTION). (2A)Do an insulation resistance check of the magnetic chip detector (refer to , INSPECTION). (3) Check the oil level (maintain the oil level by actuating the aircraft oil replenishing system).* *Oil may seep from the oil tank into the gearbox when the engine is inactive and can give a false indication of a low oil level. Check the oil level within 30 minutes after engine shutdown CF34 ENGINE MAINTENANCE PROGRAM Page 806 Sep 15/00

33 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (4)Sample oil (refer to , SERVICING).* Visually inspect the drained oil for presence of metallic particles. Visually check the oil level in the engine oil tank for evidence of overservicing and fuel contamination. * If the acid level is more than 1.5 mg KOH/g, change the oil at the next convenient time CF34 ENGINE MAINTENANCE PROGRAM Page 806A/806B Sep 15/00

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35 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (5) Visually inspect all the oil system components for leaks during the Ground Idle Run in , TESTING. (6) Do an oil filter bypass sensor indication test (refer to , TESTING). (7) Visual inspection of the C-sump scavenge screen fittings (refer to SEI-581, , figure 3, items 55A and 245) in the lube and scavenge pump for accumulation of coked oil buildup. If a 3000-hour HSI inspection has already been completed, do this inspection at the next scheduled hour inspection. E. Check the fuel system (refer to ) as follows: CF34 ENGINE MAINTENANCE PROGRAM Page 807 Sep 15/00

36 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) NOTE: If any components of the fuel system is disconnected or replaced, a leak check must be done (refer to , TESTING). (1) Replace the fuel filter element.* * The fuel filter element is the disposable type, and must be replaced every 600 hours or when the element is contaminated. If the element is contaminated, inspect and clean the fuel system (refer to , CLEANING). (2) Check for the fuel filter for a popped bypass indication button (refer to , CLEANING for corrective action). (3) Inspect the fuel filter bracket for cracks. (4) Visually inspect all fuel system components for leaks during the Ground Idle Run in , TESTING. (5) Visually inspect (refer to , INSPECTION) the housing of the oil cooler for chafing (caused by the loop clamp on the C-sump aft scavenge hose). (6) General visual inspection of the fuel pump and the main fuel control assembly. F. Check the visible areas of the fan rotor, engine inlet, and front frame (refer to , INSPECTION) for the usable limits): CF34 ENGINE MAINTENANCE PROGRAM Page 808 Sep 15/99

37 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (1) Fan spinner for: (a) Cracks. (b) Dents. (c) Looseness. (2) Fan rotor for free rotation (use your hands to turn the rotor). (3) Fan vanes for dents and cracks, and for loose or missing nuts. (4) Fan rotor blades for: (a) Unserviceable blade tip rubs (as evidenced by tip discoloration). (b) Nicks and dents. (c) Security and cracks. (d) Missing lubricant on the blade tangs (re-apply for cause only). (5) Fan disk for protruding bushings.* (6) Aluminum components of the fan casing for cracks and dents. * Only needed when N1 vibrations are above the normal operating range. The bushings should not be felt when you move a straightedge across the face of the disk CF34 ENGINE MAINTENANCE PROGRAM Page 809 Sep 15/99

38 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (7) Abradable rub strip for unserviceable rubs.* (8) Forward engine mount for security and cracks. (9) Front frame for cracks around the AGB mount pads. (10)Ignition exciter for security and damage (refer to , INSPECTION). (11)Visually inspect the water drain, in the blade removal port, for blockage. G. Check the compressor rotor and the stator assemblies (refer to , INSPECTION for the limits) for: (1) Nicks, dents, and curled tips on the rotor blades that are visible through the borescope. (2) Cracks on rotor blades that are visible through the borescope. (3) Dents and cracks in visible areas of the compressor casings. * A continuous circumferential rub more than 75% or more of the rub strip is evidence of a possible separation of the fan blade tang CF34 ENGINE MAINTENANCE PROGRAM Page 810 Sep 30/98

39 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (4) Variable vanes for: (a) Nicks and dents. (b) Cracks and excessive movement. (5) Missing lock tabs from visible variable vane outer shank nuts. (6) Rubs between variable vanes and shrouds that are visible through the borescope. (7) Distorted variable vane actuator ring. (8) Loose variable geometry system caused by worn bushings in rod end, actuator rings, and torque shaft forward bearing for migration. (9) Inspect the variable geometry feedback cable and the VG actuator attachment points for security. (10)Disengaged or bent variable vane Lever arms or turnbuckles.* * If you see any disengaged or bent lever arms or turnbuckles, the engine must be sent to an authorized GE Aircraft Engines overhaul shop CF34 ENGINE MAINTENANCE PROGRAM Page 811 Jun 30/97

40 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) WARNING: PENETRATING OIL DO NOT LET PENETRATING OIL STAY ON YOUR SKIN. PENETRATING OIL IS DANGEROUS TO YOUR SKIN AND EYES. DO NOT BREATHE THE FUMES FROM THIS OIL. MAKE SURE YOU HAVE A GOOD FLOW OF AIR. THE FUMES CAN GIVE YOU A HEADACHE AND CAN MAKE YOU DIZZY AND SICK. CAUTION: THE VG LINKAGE ROD-END BEARINGS MUST BE LUBRICATED EVERY 300 HOURS WITH PENETRATING OIL WD-40 OR LUBRICANT LPS-1 (OR EQUIVALENT) ON THE TURNBUCKLES AND THE CLEVIS ADAPTER AT 24 LOCATIONS. (11)Lubricate the surfaces of the VG rod end bearings (refer to figure 801, view A for the location) with penetrating oil WD-40 or lubricant LPS-1. (12)Overall condition of the variable geometry system. H. Check the combustion section (refer to , INSPEC- TION) for: (1) Security of the fuel manifold connections. (2) Cracks in combustion chamber frame (visible areas). (3) Nicks, dents, scratches, wear, or carbon buildup on the fuel injectors that are visible through the borescope (refer to , INSPECTION) CF34 ENGINE MAINTENANCE PROGRAM Page 812 Jun 30/97

41 Variable Geometry Actuating System - Inspection Figure CF34 ENGINE MAINTENANCE PROGRAM Page 813 Jun 30/97

42 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (4) Detailed visual inspection of the fuel injector heat shields (refer to , INSPEC- TION). (5) Hot spots, bulges, and cracks on the combustion liner during the borescope inspection. (6) Detailed visual inspection of the stages 1 and 2 nozzle assemblies. (7) Visible wear on the primary swirlers (refer to , INSPEC- TION). (8) Centering of the fuel injectors in swirlers (refer to 72-4O-00, INSPECTION) at: (a) Borescope inspection. (b) Detailed visual inspection of the swirlers after the removal of the injectors CF34 ENGINE MAINTENANCE PROGRAM Page 814 Jun 30/97

43 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) I. Check the accessory drive section (refer to , INSPECTION) for: (1) Security of the accessory gearbox brackets and the brackets on the front frame. (2) Security of the components that are installed on the gearbox. SB (3) Borescope inspection (refer to , INSPECTION) of the PTO carbon sleeve (G01 and G06 assemblies only) for forward movement. (4) Detailed inspection of the accessory gearbox mounts. J. Check the condition and the security of the isolators on the control amplifier (refer to , INSPECTION). K. Check the HPT and LPT turbine sections (refer to , INSPECTION) for: (1) Cracks, bulges, and hot spots on the casings CF34 ENGINE MAINTENANCE PROGRAM Page 815 Jun 30/97

44 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) (2) Operational defects on the LPT exposed areas of the turbine nozzles. (3) Condition of thermocouple harness (must meet all serviceable requirements in , INSPECTION). (4) Borescope inspection (refer to , INSPECTION) of the stage 1 nozzle and the HPT stage 1 blades. (5) Borescope inspection of the outer transition liner on engines SN and below that have not been modified to SB (6) Visual inspection of the stage 6 turbine blades for FOD. (7) Security of the exhaust centerbody. (8) Igniter plugs (must meet all the serviceable requirements in INSPECTION); also, refer to the note. CF34-1A/-3A only CF34-3A2 only CF34 ENGINE MAINTENANCE PROGRAM Page 816 Jun 30/97

45 TABLE 803. INSPECTION AND SERVICING REQUIREMENTS (Cont) INSPECTION TIME CATEGORIES ENGINE COMPONENT AND INSPECTION Preflight or Postflight (Refer to Para D) NOTE: For CF34-1A/-3A engines, it is recommended that one igniter plug be replaced every 300 hours. If both igniter plugs are within the inspection limits in , INSPECTION, then replace the igniter plug that has been in service longer. If neither igniter plug meets the inspection requirements, replace both igniter plugs. For CF34-3A2 engines, the igniter plugs must be inspected with the igniter plug gage PN (9) Detailed visual inspection of the HPT stages 1 and 2 shrouds. (10)Inspect the LPT stator assembly.* * If the LPT stator assembly is PN 6020T15G14, it must be returned to an authorized overhaul facility for tack welding of the pin and clip assemblies; then, after the rework, the assembly must re-identified from PN 6020T15G14 to G24. (11)Inspect the C-sump scavenge tube (at the 6 o'clock position) and the groove for internal coking; clean as required (must be within the serviceable limits in , INSPECTION). L. Do a Power Assurance Check (refer to TESTING). M. Waterwash the compressor (refer to , CLEANING).* * Engines with a high rate of landings (especially in locations where there is airborne soot, dirt, or salt) may require additional cleaning intervals. Generally, if there is a performance deterioration, noted by an increase in ITT (change margin) of 15 C (27 F) (as determined by the Power Assurance curves in , TESTING), the engine will require cleaning (refer to , CLEANING) CF34 ENGINE MAINTENANCE PROGRAM Page 817 Sep 15/01 GE PROPRIETARY INFORMATION - Subject to the restrictions on the cover or first page.