Preliminary Requirements

Procedure

1. SUBTASK 72-41-23-350-051 Remove the Damage

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

   2. Remove and blend the damage.

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

      2. The maximum depth of the repaired area(s) must be 0.005 in. (0.13 mm), unless otherwise specified in the referenced figures and paragraphs as follows.

      3. The diameter of the repaired area(s) must be 50 times the depth.

      4. Remove all sharp corners and make sure smooth blend into the adjacent material.

   3. Remove and blend the damage on flange and port faces.

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

      2. Blend must maintain a minimum 50:1 length to depth ratio.

      3. Remove only the minimum amount of material necessary to remove the damage.

      4. Remove all sharp corners and make sure a smooth blend into the adjacent material.

      5. Refer to Figure and Figure for blend limits, repair exclusion zone and edge breakout limits. Blend must not form a leak path across the boss face. Refer to Figure for internal case surface dressing limits.

         1. For PN 6B1427, individual blend length must not exceed 0.100 in. (2.540 mm). The cumulative blend must not exceed 20 percent of the surface area on any of the flange mating faces (Face 1, Face 2, Face 3, and Face 4). No blending shall be allowed within a 0.630 in. (16.00 mm) circle centered on any fastener hole on the Rear Inner Flange Forward Face.

   4. Remove and blend the damage on front flange dowel hole.

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

      2. The maximum depth of damage to be repaired is 0.041 in. (1.04 mm) in the axial direction of the dowel hole.

      3. Bore dressing:

         1. Dress and polish to remove raised metal only from bore, hole diameter must not be more than 0.240 in. (6.10 mm).

      4. End face dressing:

         1. Dress and polish raised metal flush to 0.004 in. (0.10 mm) under-flush with initial surface.

         2. Dents in flange surface around edge of hole must be polished smooth, remove minimum material (50:1 blend ratio requirement waived).

      5. Remove all sharp edges.

         NOTE

         Refer to Figure for repair requirements and limits.

   5. Remove frettage and/or crack damage from bleed duct port aperture wall surface only.

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

      2. Material removal is limited to the local areas indicated in the bleed duct port aperture wall surface, for the removal of frettage and/or crack damage only.

      3. Blend must maintain a minimum 50:1 length to depth ratio.

      4. Remove minimum material.

      5. Dress to the following limits:

         1. 0.098 in. (2.50 mm) maximum depth.

         2. 1.102 in. (28.00 mm) maximum length.

         3. 0.295 in. (7.50 mm) maximum width.

         4. 0.197 in. (5.00 mm) minimum distance between edge of repair and the nearest bolthole.

      6. Remove all sharp corners and make sure a smooth blend into the adjacent material.

      7. Refer to Figure for damage or repair locations. Do not dress the permitted cutter witness marks which are found in the same area.

   6. Remove frettage and/or crack damage from bleed duct port aperture wall surface only.

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

      2. Polish the repaired and blended area(s). Make sure all the scratches are removed and the surface finish is the same as the adjacent material.

2. SUBTASK 72-41-23-220-088 Examine the Repair

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

   2. Do a visual and dimensional inspection of the repaired area(s).

      1. Make sure blend repairs are in the repair limits, exclusion zones and edge breakout must be in repair limits.

      2. Make sure the front flange dowel hole diameter is not more than 0.240 in. (6.10 mm).

      3. If you do not get the above condition, reject the part.

3. SUBTASK 72-41-23-110-105 Chemically Clean

   1. Chemically clean the repaired area(s).

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

4. SUBTASK 72-41-23-230-056 Examine the HP Compressor Rear Outer Case for Cracks

   1. Do a penetrant crack test of the repaired area(s) by one of the methods that follow:

      1. Do a local penetrant crack test of the repaired area(s) by SPM TASK 70-23-05-230-501.

         1. Use medium sensitivity.

         2. Cracks are not permitted.

      2. Do a penetrant crack test of the repaired area(s) by SPM TASK 70-23-01-230-501 or TASK 70-23-02-230-501.

         1. Cracks are not permitted.

5. SUBTASK 72-41-23-350-002 Identify the Repair

   1. Vibration peen VRS6104 adjacent to the part number.

      1. Refer to SPM TASK 70-09-00-400-501, SUBTASK 70-09-00-400-001.

6. SUBTASK 72-41-23-380-051 Apply Surface Protection to HP Compressor Rear Outer Case

   1. Refer to Figure.

   2. Apply surface protection as necessary.

      1. To apply complete surface protection, refer to the Repair, VRS6178 TASK 72-41-23-300-003 (REPAIR-003) or to apply local surface protection.

      2. Use CoMat 07-037 CORROSION RESISTANT TOUCH-UP COATING or CoMat 07-038 AIR DRYING ENAMEL.

Figure: Repair Details and Dimensions

Repair Details and Dimensions



Figure: Typical Section Through HP Compressor Rear Outer Case

Typical Section Through HP Compressor Rear Outer Case



Figure: Extended Repair Limit Areas

Extended Repair Limit Areas



Figure: Length of Blend on Case Inner Surface Typical at All Boss Bolt Holes

Length of Blend on Case Inner Surface Typical at All Boss Bolt Holes



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