Preliminary Requirements

Safety Requirements

WARNING

USE GLOVES AND SAFETY EQUIPMENT OR MASKING WHEN YOU DO THE REPAIR. SHARP EDGES OF BLADES AND VANES CAN CAUSE INJURY TO PERSONNEL.

Procedure

1. SUBTASK 72-00-41-350-028 Examine the Rotor Assembly

   1. Refer to Figure.

   2. Examine the rotor assembly.

      1. Make sure the damaged blades are in the limits specified.

2. SUBTASK 72-00-41-350-029 Remove the Damaged Rotor Blade(s)

   1. Turn the HP compressor rotor to get access to the damaged rotor blade(s).

   2. Remove the damaged blade.

      1. For A1 model HP compressor rotor assembly, refer to TASK 72-41-10-040-001-A00.

         For A5 model HP compressor rotor assembly, refer to TASK 72-41-10-040-001-B00.

   3. NOTE

      As each rotor blade is removed, its circumferential location in the assembly must be recorded.

3. SUBTASK 72-00-41-350-030 Remove, Clean, Measure and Re-install the Nearest Serviceable Rotor Blade

   1. Refer to Figure and Figure.

   2. Remove the nearest serviceable blade.

      1. Find the damaged blade.

         Remove the nearest adjacent serviceable blade.

         For A1 model HP compressor rotor assembly refer to TASK 72-41-10-040-001-A00.

         For A5 model HP compressor rotor assembly refer to TASK 72-41-10-040-001-B00.

   3. Clean the nearest serviceable blade.

      1. Refer to TASK 72-41-15-100-000.

   4. Measure the nearest serviceable blade.

      1. Measure the blade at the three positions shown in Figure.

         Record the measurements.

         Use Workshop inspection equipment 1 off.

   5. Install the removed the serviceable blade again.

      1. Refer to TASK 72-41-10-440-000.

   6. NOTE

      Blades must be installed again at the original position in the assembly.

4. SUBTASK 72-00-41-220-071 Measure the Replacement New Blade(s)

   1. NOTE

      When you select a replacement blade choose the one that is lightly heavier than the rejected blade. This is for the removal of material from the blade tip during the blade cropping process.

      After the blade cropping process, the weight of the finished blade must be in plus or minus 0.5 gram of the original blade. If the cropped replacement blade is not in plus or minus 0.5 gram of the original blade, a new blade must be selected and the cropping process must be done again. This repair is limited to one blade only per HP compressor assembly without rebalancing. Balance check is necessary when more than one blade is replaced in this procedure.

      Refer to Figure and Figure.

   2. Measure the replacement blade(s).

      1. Measure the blade at three positions as shown in Figure.

         Record the measurements.

         Use Workshop inspection equipment 1 off.

5. SUBTASK 72-00-41-220-074 Mark-out the Replacement New Blade(s)

   1. Refer to Figure and Figure.

   2. Mark out the replacement new blade.

      1. Mark the area to be cropped from the tip on the new blade.

         Measure the blade at three positions as shown in Figure.

         Use the difference in dimensions recorded in Step and Step.

         Make sure the mark is in 0.002 in. (0.05 mm) of the necessary distance from the blade platform.

         Use Workshop inspection equipment 1 off.

         Use CoMat 02-096 MARKER PEN.

6. SUBTASK 72-00-41-350-031 Crop the Replacement New Blade

   1. 

      CAUTION

      TITANIUM COMPONENT - YOU MUST USE SILICON CARBIDE TYPE STONES AND ABRASIVE PAPERS TO DRESS, BLEND AND POLISH THIS COMPONENT.

      

      CAUTION

      TITANIUM COMPONENT - APPLY GENTLE PRESSURE AND KEEP THE TOOL SPEED AS LOW AS POSSIBLE TO PREVENT BUILD UP OF HEAT. USE TECHNIQUES WHICH WILL LET FOR PROGRESSIVE WEAR OF THE DRESSING MEDIA TO GIVE A CONTINUALLY FRESH CUTTING SURFACE TO THE WORK PIECE.

      

      CAUTION

      TITANIUM COMPONENT - DO NOT DWELL ON ONE AREA OF THE COMPONENT.

      

      CAUTION

      TITANIUM COMPONENT - DRESS WHERE POSSIBLE, IN A CIRCULAR MOTION, TAKING LIGHT CUTS TO PREVENT OVERHEATING.

      

      CAUTION

      TITANIUM COMPONENT - YOU MUST MAKE SURE THAT WHEN YOU REMOVE MATERIAL, BLEND AND POLISH TO MAKE SMOOTH, THAT NO SPARKS ARE PRODUCED.

      

      CAUTION

      TITANIUM COMPONENT - IF THE MATERIAL SHOWS A CHANGE IN COLOR TO DARKER THAN A LIGHT STRAW COLOR, THE COMPONENT MUST BE REJECTED.

      Refer to Figure and Figure.

   2. Safety the replacement blade.

      1. Safety the new blade into an applicable fixture with soft jaws.

         The fixture must safety the blade around the airfoil and at the root.

         Make sure the stage 3 rotor blade clappers are not damaged.

   3. Remove tip material by cropping.

      1. Hand crop the tip of the blade.

         Make sure the tip is dressed in the direction from the leading edge tip to the trailing edge tip.

         If necessary, use mechanical hand clutters, smooth hand metal file and/or CoMat 05-140 ABRASIVE STONE SILICON CARBIDE.

         Make sure you keep the dimensional limits set in Step.

   4. Blend and polish the replacement new blade tip.

      1. Blend and polish the replacement blade tip.

         Make sure the tip is dressed in the direction from the leading edge tip to the trailing edge tip.

         Use CoMat 05-020 WATERPROOF SILICON CARBIDE, CoMat 05-082 WATERPROOF SILICON CARBIDE and CoMat 05-127 ABRASIVE PAD.

         Make sure you keep the dimensional limits set in Step.

7. SUBTASK 72-00-41-220-072 Swab Etch the Cropped Area

   1. Do a local swab etch of the dressed area.

      1. Refer to the SPM TASK 70-11-39-300-503, SUBTASK 70-11-39-300-001.

8. SUBTASK 72-00-41-230-013 Do a Crack Test

   1. Do a local crack test of the cropped area.

      1. Refer to the SPM TASK 70-23-05-230-501.

         Use CoMat 06-063 FLUORESCENT PENETRANT (POST-EMULSIFIED MEDIUM SENSITIVITY).

         Use penetrant crack test equipment.

         Cracks are not permitted.

         If cracked, do the Step thru Step again with a new replacement blade.

9. SUBTASK 72-00-41-230-014 Chemically Clean

   1. Clean the replacement new blade.

      1. Refer to the SPM TASK 70-11-03-300-503.

         Use Chemical cleaning equipment 1 off.

10. SUBTASK 72-00-41-220-073 Examine the Replacement New Blade

    1. Refer to Figure and Figure.

    2. Dimensionally examine the replacement new blade.

       1. Measure the blade length at three positions as shown in Figure.

          Make sure the blade length is in 0.002 in. (0.05 mm) of the adjacent serviceable blade length measured.

          Use Workshop inspection equipment 1 off.

          If the blade is more than the limits, do the Step thru Step again with a new replacement blade.

11. SUBTASK 72-00-41-350-032 Identify the Replacement New Blade

    1. Refer to Figure, Figure and Figure.

    2. Mark the repair symbol at one of the indicated location(s) on the HP Compressor Rotor Blade(s).

       1. Refer to the SPM TASK 70-09-00-400-501.

       2. Mark the number 21 inside a triangle using the vibration peen method.

          1. Use Vibrating Marking Pencil 1 off.

12. SUBTASK 72-00-41-420-059 Install the Replacement new Blade

    1. NOTE

       After the blade cropping process, the weight of the finished blade must be in plus or minus 0.5 gram of the original blade. If the cropped replacement blade is not in plus or minus 0.5 gram of the original blade, a new blade must be selected and the cropping process must be done again. This repair is limited to one blade only per HP compressor assembly without rebalancing. Balance check is necessary when more than one blade is replaced in this procedure.

       The reference blade(s) used for measurement purpose must be installed again in their original positions in the assembly.

       Install the new replacement blade in the original blade set.

       1. Refer to TASK 72-41-10-440-000.

Figure: Repair Details and Dimensions

Repair Details and Dimensions



Figure: Repair Details and Dimensions

Repair Details and Dimensions



Figure: Repair Details and Dimensions

Repair Details and Dimensions



Figure: HP Compressor Stage 6 To 8 Rotor Blades - Repair Details And Dimensions

HP Compressor Stage 6 To 8 Rotor Blades - Repair Details And Dimensions



Figure: HP Compressor Stage 3 To 5 Rotor Blades - Repair Details And Dimensions

HP Compressor Stage 3 To 5 Rotor Blades - Repair Details And Dimensions



Figure: HP Compressor Stage 9 To 12 Rotor Blades - Repair Marking Zones

HP Compressor Stage 9 To 12 Rotor Blades - Repair Marking Zones



Legend

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HP Compressor Stage 9 To 12 Rotor Blades - Repair Marking Zones 1. Dovetail Side Surface Marking Area. Both Sides Of Dovetail. 2. Platform Underside Surfaces Marking Areas. Do Not Mark On Outer Edges. 3. Dovetail Bottom Surfaces Marking Areas. 4. 0.0315 Inch (0.800 mm) Minimum. 5. Corner Radius Minimum. Both Sides Of Dovetail. 6. Fillet Radius Minimum. 7. Corner Radius Minimum. 8. Distance From Dovetail Fillet Radius To The Projected Dovetail Bottom Surface. Do Not Extend Marking Into The Fillet Radius.

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