Preliminary Requirements

Procedure

1. SUBTASK 72-32-85-350-077 Remove Defective Area of Damage

   1. 
      CAUTION
      TITANIUM COMPONENTS.
      SILICON CARBIDE TYPE WHEELS, STONES AND ABRASIVE PAPERS ARE TO BE USED FOR THIS REPAIR.
      ALUMINUM OXIDE TYPES MUST NOT BE USED.
      THE MATERIAL WILL OXIDIZE AND CRACK IF MECHANICAL CUTTERS ARE USED HEAVILY. THIS HAS OCCURRED IF THE COMPONENT SHOWS DARK STRAW TO BLUE DISCOLORATION. IF AT ANY TIME THIS COLORATION OCCURS THE COMPONENT MUST BE REJECTED.
      
      CAUTION
      CHECK THE TOTAL REPAIR AREA PRIOR TO STARTING THE REPAIR. DO NOT CARRY OUT REPAIR BY FILLING THE ACOUSTIC LININGS IF THE TOTAL REPAIRED AREA EXCEEDS 20 PERCENT OF THE TOTAL FAN CASE ACOUSTIC LINING AREA.
      
      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
      DO NOT OPERATE WITHOUT SAFETY GOGGLES AND OTHER GUARD EQUIPMENT. FLYING PARTICLES CAN CAUSE INJURY.
      
      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.

      Cut away area to remove broken pieces and make a hole into damaged area.

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

      2. Refer to Figure andFigure.

      3. Be careful not to cause damage to the inner surface of the fan case assembly.

   2. NOTE

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

      Make surface flat, if necessary.

      1. Refer to Figure.

      2. Edges of damaged area must be underflush.

   3. Make sure that remaining skin surface is smooth.

      1. Burrs on edges of cut skin must be removed.

      2. Refer to Figure.

   4. Examine the repaired area ratio.

      1. Check the repaired area ratio is not more than 20 percent of one segment of acoustic lining.

      2. If more than 20 percent, Repair, VRS1540 TASK 72-32-85-300-025 (REPAIR-025).

   5. Examine the fan case inner surface of the repaired area, if necessary.

      1. Examine the fan case inner surface. Repair any nicks, dents, scratches and gouges.

      2. If necessary, do Repair, VRS1554 TASK 72-32-85-300-016 (REPAIR-016).

2. SUBTASK 72-32-85-110-055 Remove the Grease from the Repair Area

   1. 
      CAUTION
      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 VAPOUR 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 the grease from the repair area.

      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 area with air blast.

      1. Use oil free air.

3. SUBTASK 72-32-85-360-062 Prepare Filler Material

   1. Prepare the filler (CoMat 08-006 FILLER, TWO PACK).

      1. Measure out materials by weight.

         1. Refer to 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 uniform blue color. No streaks permitted.

         1. Use putty knife.

   2. NOTE

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

      NOTE

      When mixed the life of the filler is approximately half an hour 77 deg F (25 deg C).

      Prepare the sealant (CoMat 08-024 SEALANT or CoMat 08-142 POLYSULPHIDE COMPOUND).

      1. Measure out materials by weight.

         1. Use CoMat 08-024 SEALANT 75 parts of base compound and 10 parts of curing compound (accelerator) or CoMat 08-142 POLYSULPHIDE COMPOUND 100 parts of base compound and 10 parts of curing compound (accelerator) by weight.

      2. Mix the two parts by kneading until the compound is a constant color. No streaks permitted.

         1. Use putty knife.

4. SUBTASK 72-32-85-360-063 Apply Filler or Sealant Material

   1. Option 1: Apply the filler (CoMat 08-006 FILLER, TWO PACK).

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

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

      2. Use air powered sealant gun.

      3. Refer to Figure.

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

      5. Start at the bottom and work both side.

      6. The filler will gradually set.

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

   3. 
      CAUTION
      THE MAXIMUM TEMPERATURE WHICH CAN BE USED TO CURE THE FILLER IS 176 DEG F (80 DEG C).

      NOTE

      Do not put the filler in to the three water drainage slots between the lower side acoustic linings.

      NOTE

      The minimum cure time is one hour.

      Cure the filler.

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

   4. 
      CAUTION
      THE MAXIMUM TEMPERATURE WHICH CAN BE USED TO CURE THE SEALANT IS 120 DEG F (49 DEG C).

      NOTE

      Do not put the filler in to the three water drainage slots between the lower side acoustic linings.

      NOTE

      The minimum cure time is 1.5 hours. Sealant cure time with a relative humidity of 50 percent.

      Option 2: Apply the sealant (CoMat 08-024 SEALANT or CoMat 08-142 POLYSULPHIDE COMPOUND).

      1. Apply the sealant using putty knife. Remove all unwanted sealant, when it starts to feel hard.

      2. Cure the sealant for 10 hours at 77 deg F (25 deg C) or 1.5 hours at 113 deg F (45 deg C).

      3. Refer to Figure.

5. SUBTASK 72-32-85-360-099 If Necessary, Use Sealant to Fill in the Slots Between the Acoustic Linings

   1. 
      CAUTION
      THE MAXIMUM TEMPERATURE WHICH CAN BE USED TO CURE THE SEALANT IS 120 DEG F (49 DEG C).

      NOTE

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

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

      Prepare the sealant material.

      1. Use CoMat 08-024 SEALANT 75 parts of base compound and 10 parts of curing compound (accelerator) or CoMat 08-142 POLYSULPHIDE COMPOUND 100 parts of base compound and 10 parts of curing compound (accelerator) by weight.

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

      3. No streaks permitted.

   2. NOTE

      The minimum cure time is 1.5 hours. Sealant cure times with a relative humidity of 50 percent.

      Apply sealant material.

      1. Fill the sealant in the slots with putty knife.

      2. Remove all unwanted sealant, when it starts to feel hard.

      3. Cure the sealant for 10 hours at 77 deg F (25 deg C) or 1.5 hours at 113 deg F (45 deg C).

      4. Refer to Figure.

6. SUBTASK 72-32-85-220-084 Examine the Repair Area

   1. Examine the surface of the repaired area.

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

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

      3. Visually examine the slots between the acoustic linings.

      4. If necessary, do this TASK again.

      5. Refer to Figure and Figure.

Figure: Acoustic lining and typical repair

Acoustic lining and typical repair



Figure: Filling repair of acoustic linings

Filling repair of acoustic linings



Figure: Curing chart of filling material (CoMat 08-006)

Curing chart of filling material (CoMat 08-006)