Preliminary Requirements

Procedure

1. SUBTASK 72-32-85-350-052 Remove Defective Areas of Damage

   1. 
      CAUTION
      THE FAN CASE IS MADE FROM TITANIUM ALLOY AND IS THIN IN SOME AREAS. IF YOU HIT THE FAN CASE WITH A CHISEL OR SCRAPER YOU CAN MAKE IT UNSERVICEABLE.
      
      CAUTION
      YOU MUST USE THE CHISEL, SHARP BLADE OR SCRAPER IN A CIRCUMFERENTIAL DIRECTION TO PREVENT THE EDGES OF THE BLADE SCORING THE FAN CASE.
      
      CAUTION
      YOU MUST ALWAYS TRY TO POINT THE CHISEL OR SHARP BLADE PARALLEL WITH THE SURFACE OF THE FAN CASE.
      
      CAUTION
      STOP MACHINING AS SOON AS THE FILES, CUTTERS OR MACHINING BITS ARE THROUGH THE LINING MATERIAL. USE A STOP-MACHINING OR SLEEVE OR OTHER PENETRATION LIMITING DEVICE TO PREVENT DAMAGE TO THE CASING MATERIAL.
      
      CAUTION
      DO NOT USE POWERED TOOLS WITH STEEL CHISEL OR SIMILAR BITS.
      
      CAUTION
      DO NOT OPERATE WITHOUT SAFETY GOGGLES AND OTHER GUARDS EQUIPMENT. FLYING PARTICLES CAN CAUSE INJURY.

      NOTE

      Keep the material removal to the minimum necessary to remove damaged area.

      Remove loose and damaged material from repair area.

      1. Use, hand held pneumatic grinder and rotary files.

      2. Take care not to damage the GRC layer which is sandwiched between the two layers of honeycomb in this area.

      3. Refer to Figure.

   2. Check security of linings adjacent to repair area.

      1. Check visually and by tapping. A hollow sound is indicative of a suspect bond.

      2. Remove any unsound material.

      3. If the damage has reached or is below GRC layer, Repair VRS1412 TASK 72-32-85-300-003 (REPAIR-003).

   3. Make the repair area rough.

      1. Use CoMat 05-016 GARNET PAPER, 80-GRIT.

   4. Remove any remaining debris.

      1. Use vacuum cleaner.

   5. Immediately dry out the area using the air blast.

      1. Use oil free dry air.

2. SUBTASK 72-32-85-110-068 Remove the Grease from the Repair Area

   1. 
      WARNING
      ALWAYS MAKE SURE THERE IS SUFFICIENT VENTILATION IN THE WORK AREA. EYE PROTECTION MUST ALWAYS BE USED. DO NOT LET THE SOLVENT CLEANER OR ITS VAPOR TOUCH THE EYES OR SKIN. PROTECTIVE CLOTHING AND FACE MASK MUST ALWAYS BE USED. ALWAYS KEEP OPEN FLAMES AWAY FROM THE WORK AREA. IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS MATERIAL SAFETY SHEETS FROM THE CONSUMABLE MATERIALS INFORMATION SUCH AS HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

      Fully remove any grease from the repair area except the blue filler surface.

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

      2. Use CoMat 01-076 METHYL ETHYL KETONE with CoMat 02-099 LINT-FREE CLOTH.

   2. Immediately dry out the cleaned repair area with air blast.

      1. Use oil free dry air.

3. SUBTASK 72-32-85-350-053 Prepare Filler Material

   1. Measure out materials by weight.

      1. Refer to the SPM TASK 70-36-02-360-501.

      2. Use CoMat 08-006 FILLER, TWO PACK.

   2. Mix the two parts by kneading until the paste is a constant blue color.

      1. No streaks permitted.

      2. Use putty knife.

4. SUBTASK 72-32-85-350-054 Apply Filler Material

   1. Fill the filler slightly more than necessary level in the damaged area.

      1. Refer to the SPM TASK 70-36-02-360-501.

      2. Use air powered sealant gun or equivalent.

      3. Make sure that the repair area is fully filled with no air pockets.

      4. If the complete fan track is to be filled to the depth of the GRC layer, start at the bottom and work both sides.

      5. The filler will gradually set.

      6. If any sagging is apparent, locally produced supports will be necessary.

   2. 
      CAUTION
      THE MAXIMUM TEMPERATURE WHICH CAN BE USED TO CURE THE FILLER IS 176 DEG F (80 DEG C).

      NOTE

      The minimum cure time is one hour.

      Cure the filler.

      1. The cure times and temperatures are given in Figure.

   3. 
      CAUTION
      DO NOT OPERATE WITHOUT SAFETY GOGGLES AND OTHER GUARDS EQUIPMENT. FLYING PARTICLES CAN CAUSE INJURY.

      Blend filler to the contours.

      1. Use CoMat 05-016 GARNET PAPER, 80-GRIT.

      2. Refer Figure.

   4. Remove debris.

      1. Use vacuum cleaner.

5. SUBTASK 72-32-85-220-052 Examine the Repair Area

   1. Examine the surface of repair area.

      1. Make sure the shape of the filling surface is smooth.

      2. Step is acceptable if less than 0.02 in. (0.5 mm).

      3. If necessary do this task again.

      4. Refer to Figure.

Figure: Filling repair of attrition lining

Filling repair of attrition lining



Figure: Curing Chart of Filling Material (CoMat 08-006)

Curing Chart of Filling Material (CoMat 08-006)