Preliminary Requirements

Procedure

1. SUBTASK 72-32-85-110-077 Clean the Damaged Area

   1. Clean the repair area.

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

2. SUBTASK 72-32-85-220-193 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.

      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 72-32-85-350-111 Blend Repair the Fan Case (01-100)

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

   2. 
      WARNING
      DO NOT OPERATE WITHOUT SAFETY GOGGLES AND OTHER GUARDS EQUIPMENT. FLYING MATERIAL CAN CAUSE EYE INJURY.
      
      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.

      NOTE

      Dull tools and worn or loaded abrasive equipment generated heat rapidly and should be checked frequently and replaced when necessary.

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

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

      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.

      1. Refer to Figure, Figure, Figure, Figure, Figure, Figure, and Figure for blend requirements.

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

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

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

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

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

4. SUBTASK 72-32-85-110-078 Clean the Repaired Area

   1. Clean the repair area.

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

5. SUBTASK 72-32-85-220-122 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 procedure 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 , Figure, Figure, and Figure requirements.

      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.

      2. Measure the dimensions of the blended areas.

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

6. SUBTASK 72-32-85-110-079 Do a Swab Etch

   1. Clean the repair area.

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

   2. Swab etch the repaired area(s).

      1. Refer to SPM TASK 70-11-08-300-503.

      2. Use chemical etching equipment.

7. SUBTASK 72-32-85-230-065 Do a Crack Test

   1. Do the test for cracks.

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

      2. No cracks are permitted.

8. SUBTASK 72-32-85-360-108 Fill the Repaired Area, if the Blended Depth is more than 0.010 in. (0.25 mm) at the Location 4 and 5E

   1. Degrease the repaired area. Refer to Figure, Figure, Figure, Figure, and Figure.

      1. 
         CAUTION
         DO NOT GET CLEANING FLUID ON YOUR SKIN OR IN YOUR EYES. PUT ON PROTECTIVE CLOTHING, GOGGLES AND A FACE MASK. USE THE FLUID IN A WELL VENTILATED AREA. DO NOT BREATHE THE VAPOR. IF YOU GET THE CLEANING FLUID ON YOUR SKIN OR IN YOUR EYES FLUSH IT AWAY WITH WATER. GET MEDICAL AID IF YOUR SKIN OR EYES BECOME IRRITATED.

         NOTE

         Always pour cleaning fluid on the cloth to avoid contaminating the cleaning fluid supply. Wash one small area at a time.

         It is important that the surface is dried with a second clean cloth prior to the cleaning fluid evaporating to prevent the redeposition of contaminants on the fan case surface.

         Remove all grease from the repaired area.

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

   2. Apply adhesion promoter. Refer to Figure and Figure.

      1. 
         WARNING
         YOU MUST FIND AND OBEY THE MANUFACTURER'S HEALTH AND SAFETY DATA FOR THE MATERIAL (MSDS). YOU MUST ALSO REFER TO LOCAL REGULATIONS TO MAKE SURE THAT THE PROCEDURES ARE DONE SAFELY. IF YOU DO NOT DO THIS, AN INJURY OR ENVIRONMENTAL DAMAGE CAN OCCUR.

         Apply the primer.

         1. Apply a thin coat of CoMat 08-155 ADHESION PROMOTER to the cleaned surface by brush or clean gauze and allow to dry for approximately 30 minutes at room temperature.

   3. Apply the sealant. Refer to Figure and Figure.

   4. 
      WARNING
      YOU MUST FIND AND OBEY THE MANUFACTURER'S HEALTH AND SAFETY DATA FOR THE MATERIAL (MSDS). YOU MUST ALSO REFER TO LOCAL REGULATIONS TO MAKE SURE THAT THE PROCEDURES ARE DONE SAFELY. IF YOU DO NOT DO THIS, AN INJURY OR ENVIRONMENTAL DAMAGE CAN OCCUR.

      NOTE

      You must use the plastic gloves, during preparation and use of the sealant, to prevent contamination of the skin.

      The life of the mixed sealant is approximately half an hour, at 77 deg F (25 deg C).

      Apply the adhesive.

      1. Prepare the adhesive.

         1. Prepare the sealant.

            1. Use CoMat 08-024 SEALANT 75 parts of base compound and 10 parts of curing compound (accelerator) by weight. Mix the two parts by kneading until the color of compound is constant quality. No streaks permitted.

   5. Cure the sealant.

      1. NOTE

         Make sure the full cure time is used and correct temperature maintained.

         Let the sealant cure for 24 hours at ambient temperature 77 deg F (25 deg C) or heat to 113 deg F (45 deg C) for minimum 6 hours.

   6. Remove unwanted sealant. Refer to Figure and Figure.

      1. Remove all unwanted sealant, when it starts to feel hard. If the remaining sealant material around the repair area is not more than 0.020 in. (0.50 mm), dress the sealant material with CoMat 05-020 WATERPROOF SILICON CARBIDE, if necessary.

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

      1. Make sure that the potting limit for repaired area is not more than the given limit.

9. SUBTASK 72-32-85-350-141 Identify the Repair

   1. Make a mark VRS1805 adjacent to the part number.

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

      2. Use vibro-engraving equipment.

      3. If the repair has been performed in Location 7 make a mark VRS1805-7, in Location 8 make a mark VRS1805-8 and in Location 9 make a mark VRS1805-9.

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



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