Preliminary Requirements

Procedure

1. SUBTASK 72-32-85-110-086 Clean the Damaged Area

   1. Clean the repair area.

      1. Refer to the SPM TASK 70-11-26-300-503. Use cleaning equipment.

2. SUBTASK 72-32-85-220-196 Examine the Damaged Area of the Fan Case (01-100)

   1. Refer to Figure and Figure.

   2. NOTE

      Make sure that ultrasonic wall thickness measuring equipment was calibrated by the necessary procedures given in operation manuals of the measuring equipment or local regulations. Calibration piece to be made from the same material (Ti-6A1-4V) or a material with the same acoustic velocity as the part to be tested.

      NOTE

      The calibration piece thickness must be within the thickness limits of the part to be measured, refer to Figure.

      NOTE

      A replica produced by filling a mold with a casting compound, such as elastomer or plastic, and letting it harden inside the impression, taking on the damaged shape and surface details of the original specimen.

      Visually examine and measure the dimensions of the damaged area.

      1. Make sure the damage can be repaired within the specified limits.

      2. If the damage is within locations 7, 8 and/or 9 it is recommended that the damage depth and the wall thickness of the area adjacent to the damage is noted. The thickness can be measured with ultrasonic wall thickness measuring equipment.

      3. The depth of damage can be measured with dimensional inspection equipment and CoMat 08-133 SURFACE REPLICATING MATERIAL.

3. SUBTASK 72-32-85-350-069 Blend Repair the Fan Case (01-100)

   1. Refer to Figure, Figure, Figure and Figure.

   2. 

      CAUTION

      TITANIUM COMPONENT - YOU MUST USE SILICON CARBIDE TYPE ABRASIVE WHEELS, STONES AND PAPERS TO DRESS, BLEND AND POLISH THIS COMPONENT. IF MECHANICAL CUTTERS ARE USED, ONLY LIGHT CUTS MUST BE MADE TO AVOID OVERHEATING THE MATERIAL.

      

      CAUTION

      TITANIUM COMPONENT - AVOID BUILD UP OF HEAT BY APPLYING ONLY GENTLE PRESSURE AND KEEPING THE TOOL SPEED AS LOW AS POSSIBLE. USE TECHNIQUES WHICH ALLOW FOR PROGRESSIVE WEAR OF THE DRESSING MEDIA TO PRESENT A CONTINUALLY FRESH CUTTING SURFACE TO THE WORK PIECE. DO NOT DWELL ON ONE AREA OF THE COMPONENT. DRESS, WHERE POSSIBLE, IN A CIRCULAR MOTION, TAKING LIGHT CUTS TO AVOID OVERHEATING.

      

      CAUTION

      TITANIUM COMPONENT - YOU MUST MAKE SURE THAT WHEN YOU REMOVE MATERIAL, BLEND AND POLISH, TO MAKE SMOOTH, THAT NO SPARKS ARE PRODUCED AND THE ADJACENT AREA IS MASKED OFF.

      

      CAUTION

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

      

      CAUTION

      POWER BLENDING TOOLS CAN BE USED IF DAMAGED TITANIUM PART IS PERIODICALLY CHECKED FOR HEAT BUILD-UP BY TOUCHING OCCASIONALLY WITH UNGLOVED HAND. IF TITANIUM PART BECOMES TOO HOT TO TOUCH, ALLOW MATERIAL TO COOL BEFORE CONTINUING REPAIR.

      

      CAUTION

      THE FAN CASE IS MADE FROM TITANIUM ALLOY AND IS THIN IN SOME AREAS. IF YOU BLEND TOO MUCH, THE PART CANNOT BE SERVICEABLE AND WILL HAVE TO BE REPLACED.

      

      CAUTION

      DO NOT OPERATE WITHOUT SAFETY GOGGLES AND OTHER GUARDS EQUIPMENT. FLYING PARTICLES CAN CAUSE INJURY.

      NOTE

      Dull tools and worn or loaded abrasive equipments generate heat rapidly and should be checked frquently and replaced when necessary.

      NOTE

      The blend ratio, length to depth, must be a minimum of 30:1. Refer to Figure.

      NOTE

      Remove the minimum quantity of material necessary to remove the damage. All blends must be smooth and continuous.

      NOTE

      The surface finish of all the repaired surfaces must have the same or better quality to that of the adjacent, not damaged, areas.

      Blend the fan case surface damage such as dents, nicks, scratches, wear, fretting, galling distortion.

   3. Refer to Figure, Figure, Figure and Figure for blend limit requirements.

   4. Use portable blending equipment, CoMat 05-020 WATERPROOF SILICON CARBIDE and CoMat 05-021 WATERPROOF SILICON CARBIDE.

   5. Continue to remove material until all the damage is removed.

   6. The blend must be smooth and continuous into the original contour in all directions.

   7. The surface finish of all blended areas must be as smooth as the original finish.

   8. Refer to SPM TASK 70-35-03-300-501.

4. SUBTASK 72-32-85-110-087 Cleaned the Repaired Area

   1. Clean the repair area.

      1. Refer to the SPM TASK 70-11-26-300-503.

      2. Use cleaning equipment.

5. SUBTASK 72-32-85-220-072 Examine the Blend Repaired Area of the Fan Case (01-100)

   1. Visually examine and measure the dimensions of the repaired area.

      1. NOTE

         Make sure that ultrasonic wall thickness measuring equipment was calibrated by the necessary procedures given in operation manuals of the measuring equipment or local regulations. Calibration piece to be made from the same material (Ti-6A1-4V) or a material with the same acoustic velocity as the part to be tested.

         The calibration piece thickness must be within the thickness limits of the part to be measured, refer to Figure.

         Make sure the surface finish is the same as the adjacent material.

      2. Make sure the dimensions are within the specified limits. Refer to Figure and Figure requirement.

      3. If the repair is within locations 7, 8 and/or 9. The minimum wall thickness must be measured. The thickness can be measured with ultrasonic wall thickness measuring equipment.

   2. Examine the ratio of the blended area dimensionally.

      1. Refer to Figure. Measure the dimensions of the blended areas.

      2. The blend area ratio, length to depth, must be a minimum of 30:1.

6. SUBTASK 72-32-85-110-088 Do a Swab Etch

   1. Clean the repair area.

      1. Refer to the SPM TASK 70-11-26-300-503.

      2. Use cleaning equipment.

   2. Swab etch the repaired area(s).

      1. Refer to the SPM TASK 70-11-08-300-503, SUBTASK 70-11-08-300-002.

      2. Use chemical etching equipment.

7. SUBTASK 72-32-85-230-068 Do a Crack Test

   1. Do the test for cracks.

      1. Refer to the SPM TASK 70-23-05-230-501. No cracks are permitted.

8. SUBTASK 72-32-85-350-144 Identify the Repair

   1. Make a mark VRS1554 adjacent to the part number.

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

      2. Use Vibrating marking pencil.

      3. If the repair has been performed in location 7 make a mark VRS1554-7, in location 8 make a mark VRS1554-8 and in location 9 make a mark VRS1554-9.

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: Repair Details and Dimensions

Repair Details and Dimensions