* * * FOR ALL
TASK 72-31-44-200-801
1.General.
A.This procedure gives instructions to do an inspection of the HPC stage 5 (blisk). Refer to Figure 803.
•
Blisk (01-490 ,72-31-00)
•
Blisk (01-490A ,72-31-00) (SB 72-0020)
•
Blisk (02-490 ,72-31-00) (SB 72-0157)
•
Blisk (02-490 ,72-31-00) (SB 72-0492).
B.There are several configurations of the stage 5 blisk. The PRE SB 72-0020 blisk has an oval bolthole and a forward damper tab. The SB 72-0020 blisk has a rounded bolthole and does not have a forward damper tab. The SB 72-0157 blisk is GEnx-1B PIP2 capable. The SB 72-0492 has machined airfoil tip, to repair part with tip discoloration.
C.Use the 11C3185  lift fixture to position, lift, or turn the blisk in the working area. Refer to Subtask 72-31-44-420-002 (paragraph 3.A.) for instructions about installation and removal of the tool.
2.Tools, Equipment, and Materials.
NOTE:
You can use equivalent alternatives for tools, equipment, and consumable materials.
A.Tools and Equipment.
(1)Special Tools.
 
Tool No.
Description
 
--
Inspection Kit, Eddy Current-Bore (inspection kit)
 
11C3185G02
Fixture, Lift/Turn - HP Compressor Rotor, Stage 5 Blisk (lift fixture)
 
9429M77G04
Fixture, Lift and Turn - General Purpose (lift/turn fixture)
(2)Standard Tools and Equipment.
 
Tool No.
Manufacturer
 
Eddy Current Inspection Kit GE-FQAP-428
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Guide Fixture for Rohmann Standard Rotors (GE-FQAP-302)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Guide Fixture for Staveley RA Scanners (GE-FQAP-302A)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Guide Fixture for Hocking Rotors (GE-FQAP-302B)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Guide Fixture for Staveley Rotors (GE-FQAP-302D)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Guide Fixture for Uniwest Rotors (GE-FQAP-302E)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
High Speed Eddy Current Inspection Kit (GE-FQAP-652)
GE Inspection Technologies
Attn: NDE Kit Coordinator
50 Industrial Park Road
Lewistown, PA 17044
E-mail: ndttooling@ge.com
Fax: 513-552-1386
 
Mandrel, 9970-958-276G01 (mandrel)
SNECMA
NOTE:
Mandrel 9970-958-276G01 is given as an alternative to any other tooling compatible with the automatic installation.
(3)Locally Manufactured Tools. None.
B.Consumable Materials. None.
C.Referenced Procedures.
 
ATA No.
Description
 
70-22-06
Special Cleaning Procedure 6 - Bolthole Cleaning for Eddy Current Inspection
 
70-32-02
Fluorescent Penetrant Inspection
 
70-32-07
High Speed and Slow Speed Eddy Current Inspection of Circular Holes in Inconel or Titanium Engine Parts
 
70-32-10
2 MHz Eddy Current Inspection of Bores in Inconel Alloy Rotating Engine Hardware Using Systems Under Computer, Numeric, or Robotic Control
 
70-33-03
Special Inspection for Surface Fretting or Galling
 
70-42-00
Blending and Removal of High Metal Procedures
D.Expendable Parts. None.
3 . Tool Installation and Removal.
Subtask 72-31-44-420-002
A.Install the 11C3185  lift fixture. Refer to Figure 801 and do as follows:
(1)Put the support (item 11) below the forward side of the blisk.
(2)Put the clamp (item 12) on the blisk and align it with the support (item 11). Use the holes on the two items as a reference.
(3)Attach firmly the clamp (item 12) against the support (item 11) with the knob (item 13).
(4)Install the other support (item 11) and clamp (item 12) assembly 180 degrees apart from the first assembly to make sure that the blisk is balanced when it is lifted.
(5)Attach firmly the other clamp (item 12) against the support (item 11) with the knob (item 13).
(6)Install the 9429M77  lift/turn fixture on the 11C3185  lift fixture.
(7)Put the lock plate adapter (item 13) on the 11C3185   lift fixture and attach it with the release pin (item 19).
(8)Use the 9429M77  lift/turn fixture to move the 11C3185  lift fixture.
Subtask 72-31-44-020-002
B.Remove the 11C3185  lift fixture. Refer to Figure 801 and do as follows:
(1)Remove the 9429M77  lift/turn fixture from the 11C3185  lift fixture as follows:
(a)Remove the release pin (item 19) and lock plate adapter (item 13) from the 11C3185  lift fixture.
(2)Loosen the knob (item 13).
(3)Remove the supports (item 11) and clamps (item 12) from the blisk.
* * * FOR ALL
Figure 801   (Sheet 1) Installation/Removal of the Lift Fixture, 11C3185, on the Blisk
* * * FOR ALL
Figure 801   (Sheet 2) Installation/Removal of the Lift Fixture, 11C3185, on the Blisk
4 . Specific Inspection Procedure.
NOTE:
Any findings beyond manual limits that may be indicative of a possible crack and/or metallurgical defect must be reported to GE through a myGEAviation Technical Inquiry.
Subtask 72-31-44-230-001
WARNING:
ALWAYS USE APPROVED EQUIPMENT AND PROCEDURES TO LIFT PARTS. STAY OUT FROM BELOW LOADS. IF THE PARTS ACCIDENTALLY MOVE OR FALL, THEY CAN CAUSE AN INJURY OR KILL YOU.
WARNING:
BECAUSE OF ENGINE OPERATION, THE AIRFOIL TIPS CAN HAVE SHARP EDGES AND CORNERS. BE CAREFUL AND USE APPROPRIATE PROTECTIVE EQUIPMENT TO PREVENT INJURY.
A.Do a Class G fluorescent penetrant inspection of the blisk. Refer to TASK 70-32-02-230-001 (FLUORESCENT PENETRANT INSPECTION).
(1)Make sure you do a careful inspection of the critical area that follows:
•
Disk bore
•
Bolt holes
•
Fillets
•
Airfoils.
(2)Indications 0.015 inch (0.38 mm) or less are permitted.
Subtask 72-31-44-230-002
WARNING:
ALWAYS USE APPROVED EQUIPMENT AND PROCEDURES TO LIFT PARTS. STAY OUT FROM BELOW LOADS. IF THE PARTS ACCIDENTALLY MOVE OR FALL, THEY CAN CAUSE AN INJURY OR KILL YOU.
WARNING:
BECAUSE OF ENGINE OPERATION, THE AIRFOIL TIPS CAN HAVE SHARP EDGES AND CORNERS. BE CAREFUL AND USE APPROPRIATE PROTECTIVE EQUIPMENT TO PREVENT INJURY.
B.Do a Class G non-aqueous wet developer (NAWD) fluorescent penetrant inspection of the bolt holes. Refer to TASK 70-32-02-230-001 (FLUORESCENT PENETRANT INSPECTION).
Subtask 72-31-44-250-001
C.Do an eddy current inspection of the blisk bore as follows. Refer to Figure 802.
(1)Clean the blisk. Refer to TASK 72-31-44-100-801 (72-31-44, CLEANING 001).
Subtask 72-31-44-250-004
(2)Do an eddy current inspection of the bore surfaces. Refer to TASK 70-32-10-250-003 (2 MHZ EDDY CURRENT INSPECTION OF BORES IN ROTATING ENGINE HARDWARE USING SYSTEMS UNDER COMPUTER, NUMERIC, OR ROBOTIC CONTROL).
NOTE:
Only trained personnel identified and approved to do these inspections can do these tests.
•
The authority to accept/reject hardware will not be given to the inspectors until they are certified.
•
They must show they can satisfactorily do the necessary calibration and inspection procedures and correctly read the inspection results.
•
Changes to the procedure or substitutions for the equipment can cause the detection of less cracks. When other equipment or procedure is used, it must be evaluated by the General Electric Company.
•
Material is Inconel 718. Use correction factors for calibration as necessary. Refer to TASK 70-32-10-250-003 (2 MHZ EDDY CURRENT INSPECTION OF BORES IN ROTATING ENGINE HARDWARE USING SYSTEMS UNDER COMPUTER, NUMERIC, OR ROBOTIC CONTROL).
(b)Inspect the bore areas shown in the scan plan.
NOTE:
Do not scan the part marking or stack projection marking in area A as the markings can show up as indications.
(c)Complete the eddy current data sheets.
(d)Eddy current inspection evaluation limits.
1The evaluation limit is 1500 mV.
(e)Eddy current inspection reject limits.
1The reject limit is 1500 mV after evaluation is complete.
(f)All stage 5 HPC blisks that are rejected are not serviceable. All blisks that are not rejected are serviceable.
Subtask 72-31-44-250-005
(g)Make sure that all records that were made during the eddy current inspection are complete. Permanently keep these records for each stage 5 HPC blisk that was inspected.
* * * FOR ALL
Figure 802   HPC Rotor Stage 5 Blisk - Eddy Current Bore Inspection Plan
Subtask 72-31-44-250-003
* * * SB  72-0157
* * * SB  72-0020 ( Introduction of New Stage 5 Blisk )
D.Do an eddy current inspection of the blisk boltholes as follows:
CAUTION:
DO NOT USE METAL BRUSHES TO CLEAN THE BOLTHOLES. METAL BRUSHES CAN CAUSE SCRATCHES. SCRATCHES CAN CAUSE THE SHAFT TO BE REJECTED DURING THE EDDY CURRENT INSPECTION.
(1)Clean the blisk. Refer to TASK 72-31-44-100-801 (72-31-44, CLEANING 001).
NOTE:
It is recommended to use a stiff nylon bottle brush to remove surface oxide and/or smut from the vent hole surfaces.
(2)If necessary, mechanically clean the bolthole surfaces. Refer to TASK 70-22-06-110-043 (SPECIAL CLEANING PROCEDURE 6 - BOLTHOLE CLEANING FOR EDDY CURRENT INSPECTION).
Subtask 72-31-44-250-006
(3)Do an eddy current inspection of the boltholes. Refer to TASK 70-32-07-250-001 (HIGH SPEED AND SLOW SPEED EDDY CURRENT INSPECTION OF CIRCULAR HOLES IN INCONEL OR TITANIUM ENGINE PARTS).
NOTE:
Only trained personnel identified and approved to do these inspections can do these tests.
•
The authority to accept/reject hardware will not be given to the inspectors until they are certified.
•
They must show they can satisfactorily do the necessary calibration and inspection procedures and correctly read the inspection results.
•
Changes to the procedure or substitutions for the equipment can cause the detection of less cracks. When other equipment or procedure is used, it must be evaluated by the General Electric Company.
(a)Do an eddy current inspection of the boltholes as follows:
1Use the GE-FQAP-652 inspection kit with either the GE-FQAP- 302 inspection kit, GE-FQAP-302A inspection kit, GE-FQAP-302B inspection kit, or GE- FQAP-302C inspection kit.
2Use the following filter settings for the equipment used to do the eddy current inspection:
 
Rohmann B1 - Filter Frequency
1000 Hz BP
 
Rohmann B1V3/V4 - Filter Frequency
High Pass 500 Hz
Low Pass 1.25 KHz
 
Staveley NDT 19, Nortec 24 and Nortec 2000
High Pass 350 Hz
Low Pass 500 Hz
 
Hocking Phasec 1.1
High Pass 250 Hz
Low Pass 1.5 KHz
 
Hocking 2200
High Pass 400 Hz
Low Pass 2 KHz
 
Uniwest US-454
High Pass 400 Hz
Low Pass 1.25 KHz
(b)Eddy current inspection evaluation limits.
1For high speed eddy current inspection, the evaluation limit is four major divisions.
(c)Eddy current inspection reject limits.
1For high speed eddy current inspection, the rejection limit is four major divisions after the evaluation is complete.
(d)All stage 5 blisks that are rejected are not serviceable.
Subtask 72-31-44-250-007
(e)Make sure that all records that were made during the eddy current inspection are complete. Permanently keep these records for each stage 5 blisk that was inspected.
NOTE:
There is no pre condition for SB 72-0020.
* * * END SB  72-0020
* * * END SB  72-0157
5 . Visual Inspection.
Refer to Figure 803.
Subtask 72-31-44-220-043
A.Do an inspection of all areas for:
(1)Cracks:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-007
B.Do an inspection of area A (critical) of the blisk airfoils for. Refer to Figure 805.
* * * PRE SB  72-0492
(1)Blended fillet in the leading edge area. Refer to Figure 804 and do as follows:
NOTE:
Some leading edge fillets can have been boro-blended on engine level or module level. Typical depth of blend is 0.020 to 0.025 inch (0.51 to 0.63 mm) in depth. This condition cannot be permitted on piece part level, even if only the first root fillet was blended.
NOTE:
SB 72-0492 provides instructions to alter the part.
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
* * * END PRE SB  72-0492
Subtask 72-31-44-220-070
* * * SB  72-0492
(2)Blended fillet in the leading edge area. Refer to Figure 804 and do as follows:
NOTE:
Some leading edge fillets can have been boro-blended on engine level or module level. Typical depth of blend is 0.020 to 0.025 inch (0.51 to 0.63 mm) in depth.
Maximum serviceable limit:
Any amount, 0.025 inch (0.63 mm) in depth, after shot-peen. Refer to TASK 72-31-44-300-XXX (72-31-44, REPAIR 005).
Repair method:
Repair. Refer to (72-31-44, REPAIR 005).
* * * END SB  72-0492
Subtask 72-31-44-220-069
(3)Nicks and pits in the fillet (except leading edge):
Maximum serviceable limit:
Any amount 0.003 inch (0.08 mm) in depth.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-071
* * * PRE SB  72-0492
(4)Nicks and pits in the leading edge of the fillet:
NOTE:
SB 72-0492 provides instructions to alter the part.
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth.
Repair method:
Replace the blisk.
* * * END PRE SB  72-0492
Subtask 72-31-44-220-072
* * * SB  72-0492
(5)Nicks and pits in the leading edge of the fillet:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth.
Repair method:
Repair. Refer to (72-31-44, REPAIR 005).
* * * END SB  72-0492
Subtask 72-31-44-220-073
* * * PRE SB  72-0492
(6)Dents in the leading edge of the fillet:
NOTE:
SB 72-0492 provides instructions to alter the part.
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth.
Repair method:
Replace the blisk.
* * * END PRE SB  72-0492
Subtask 72-31-44-220-074
* * * SB  72-0492
(7)Dents in the leading edge of the fillet:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth.
Repair method:
Repair. Refer to (72-31-44, REPAIR 005).
* * * END SB  72-0492
Subtask 72-31-44-220-044
(8)Dent in the fillet (except the leading edge of the fillet):
Maximum serviceable limit:
Any amount 0.003 inch (0.08 mm) in depth, 0.020 inch (0.51 mm) in length or diameter.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-045
(9)Scratches in the fillet (except the leading edge):
Maximum serviceable limit:
Any amount 0.003 inch (0.08 mm) in depth, 0.010 inch (0.25 mm) in length. No transverse scratches.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-078
* * * PRE SB  72-0492
(10)Scratches in the leading edge of the fillet:
NOTE:
SB 72-0492 provides instructions to alter the part.
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, 0.010 inch (0.25 mm) in length. No transverse scratches.
Repair method:
Replace the blisk.
* * * END PRE SB  72-0492
Subtask 72-31-44-220-075
* * * SB  72-0492
(11)Scratches in the leading edge of the fillet:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, 0.010 inch (0.25 mm) in length. No transverse scratches.
Repair method:
Repair. Refer to (72-31-44, REPAIR 005).
* * * END SB  72-0492
Subtask 72-31-44-220-046
(12)Tears and cracks in the leading edge of the fillet:
NOTE:
Contact GE Aviation fleet support for repair feasibility.
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-076
(13)Tears and cracks in the fillet except the leading edge of the fillet:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-047
(14)Nicks, dents, and pits on the leading and trailing edges:
Maximum serviceable limit:
Any amount 0.010 inch (0.25 mm) in depth.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-048
(15)Tears and cracks on the leading and trailing edges:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-049
(16)Deposits on the leading and trailing edges:
Maximum serviceable limit:
0.005 inch (0.13 mm) in thick.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-050
(17)Scratches and gouges on the leading and trailing edges:
Maximum serviceable limit:
Any amount 0.003 inch (.08 mm) in depth and 0.142 inch (3.61 mm) in length.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-051
(18)Bulge deformation on the leading and trailing edges:
Maximum serviceable limit:
Any amount, no more than 0.020 inch (0.51 mm) maximum distortion from the original leading or trailing edge contour.
Repair method:
Replace the blisk.
* * * FOR ALL
Figure 803   (Sheet 1) Blisk - Inspection Area
* * * FOR ALL
Figure 803   (Sheet 2) Blisk - Inspection Area
* * * FOR ALL
Figure 804   (Sheet 1) Blisk - Leading Edge Root Fillet Inspection
* * * FOR ALL
Figure 804   (Sheet 2) Blisk - Leading Edge Root Fillet Inspection
* * * FOR ALL
Figure 804   (Sheet 3) Blisk - Leading Edge Root Fillet Inspection
Subtask 72-31-44-220-009
C.Do an inspection of area B (leading and trailing edges) on the blisk airfoils for:
(1)Nicks:
Maximum serviceable limit:
Any amount, 0.015 inch (0.38 mm) in depth, after the removal of high metal. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-010
NOTE:
Shallow or small wavy areas at the leading and trailing edges are normal and must not be interpreted as dents.
(2)Dents and pits:
Maximum serviceable limit:
Any amount, 0.015 inch (0.38 mm) in depth, and more than 0.40 inch (10.2 mm) between defects, after the removal of high metal. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-011
(3)Scratches and gouges:
Maximum serviceable limit:
Any amount, 0.005 inch (0.13 mm) in depth, and 0.157 inch (3.99 mm) in length, after the removal of high metal. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-012
(4)Deposits:
Maximum serviceable limit:
0.005 inch (0.13 mm) in thickness.
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-013
(5)Metal splatter deposits:
Maximum serviceable limit:
0.005 inch (0.13 mm) in thickness.
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-014
(6)Erosion on the leading edge:
Maximum serviceable limit:
Any amount if in dimensional limits of Subtask 72-31-44-220-037 (paragraph 5) .
Repair method:
Replace the blisk.
Subtask 72-31-44-220-015
(7)Cracks:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-016
(8)Bulge deformation:
Maximum serviceable limit:
Any amount, no more than 0.020 inch (0.51 mm) maximum distortion from the original leading or trailing edge contour in the lower 30 percent span of the airfoil.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-055
(9)Tears:
Maximum serviceable limit:
Not serviceable.
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-017
D.Do an inspection of area C (concave and convex airfoil contour surfaces) of the blisk blade for:
(1)Nicks, dents, and pits:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, 0.020 inch (0.51 mm) in length or in diameter. Defects at the same location on opposite sides of the airfoil are not permitted.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-018
(2)Scratches:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, any length. Transverse scratches are not permitted.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-019
(3)Metal splatter deposits:
Maximum serviceable limit:
0.005 inch (0.13 mm) in thick.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-020
E.Do an inspection of the airfoil for:
(1)Bent airfoil:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-021
F.Do an inspection of the flowpath surface of the blisk for:
(1)Nicks, dents, pits, and scratches:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, any length, if there is no high metal.
Repair method:
Repair. Refer to TASK 72-31-44-300-802 (72-31-44, REPAIR 001) .
Subtask 72-31-44-220-022
G.Do an inspection of the blade tip of the blisk for. Refer to Figure 806 and Figure 807.
(1)Nicks, dents, and cracks:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-023
(2)Tip rub:
NOTE:
Tip rub indications must lead to tip height inspection, as described in paragraph 6: Special Dimensional Inspection.
Maximum serviceable limit:
Any amount.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-024
(3)Burrs and high metal:
NOTE:
Tip burrs and high metal must lead to tip height inspection, as described in paragraph 6: Special Dimensional Inspection.
Maximum serviceable limit:
Not serviceable.
Maximum repairable limit:
Any amount.
Repair method:
Blend to remove burrs and high metal. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Subtask 72-31-44-220-025
* * * PRE SB  72-0492
(4)Heat discoloration caused by tip rub:
NOTE:
Parts can be altered for SB 72-0492.
NOTE:
Tip discoloration caused by tip rub must lead to tip height inspection, as described in paragraph 6: Special Dimensional Inspection.
NOTE:
Clean the airfoils before heat discoloration inspection. Abrasive cleaning methods must not be used on airfoils, as they might make discoloration inspection more difficult.
NOTE:
Discoloration with tip contact marks (rubs, burrs) is rejectable. Discoloration with no tip contact marks (rubs, burrs) is acceptable.
NOTE:
All airfoil tips must be inspected. Even one each airfoil with tip contact mark can lead to tip discoloration.
Maximum serviceable limit:
Any color or amount that is less than 0.05 inch (1.3 mm) from the blisk blade tip.
Repair method:
Replace the blisk.
* * * END PRE SB  72-0492
Subtask 72-31-44-220-077
* * * SB  72-0492
(5)Heat discoloration caused by tip rub:
Maximum serviceable limit:
Any amount.
Repair method:
N/A.
* * * END SB  72-0492
Subtask 72-31-44-220-026
(6)Deposits:
Maximum serviceable limit:
0.005 inch (0.13 mm) in thick.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-027
(7)Bending and curling of the squealer tip:
Maximum serviceable limit:
10 percent chord and 10 percent span, if there are no cracks, four blades maximum permitted, a minimum of 60 degrees apart.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-028
(8)Erosion:
Maximum serviceable limit:
Any amount if in the dimensional limits of Subtask 72-31-44-220-037 (paragraph 5) .
Repair method:
Replace the blisk.
Subtask 72-31-44-220-030
H.Do an inspection of the tip corners of the blisk airfoils for:
(1)Damage:
Maximum serviceable limit:
Not serviceable.
Repair method:
Repair. Refer to TASK 72-31-44-300-801 (72-31-44, REPAIR 002).
Subtask 72-31-44-220-031
I.Do an inspection of all disk surfaces (does not include the airfoils) for:
(1)Nicks and scratches:
Maximum serviceable limit:
Any amount, if not more than 0.50 inch (12.7 in length or more than 0.003 inch (0.08 mm) in depth. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Repair method:
Replace the blisk.
Subtask 72-31-44-220-032
(2)Dents:
Maximum serviceable limit:
Any amount, 0.003 inch (0.08 mm) in depth, after the removal of high metal. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES) .
Repair method:
Replace the blisk.
Subtask 72-31-44-220-033
J.Do an inspection of the boltholes for:
(1)Nicks, dents, pits, and scratches on the inner diameter:
Maximum serviceable limit:
Not serviceable.
Repair method:
Replace the blisk.
Subtask 72-31-44-220-036
K.Do an inspection of the bolt pad faces for:
(1)Fretting and galling:
Maximum serviceable limit:
Any amount, if in the limits of TASK 70-33-03-220-006 (SPECIAL INSPECTION FOR SURFACE FRETTING OR GALLING) .
Repair method:
Replace the blisk.
Subtask 72-31-44-220-067
L.Do an inspection of the forward rabbet and aft rabbet (diameter Y and diameter AZ) for:
NOTE:
Forward rabbet and aft rabbet can have thermal spray coating. If damaged coating is found, it must be completely removed.
(1)Fretting and galling on parent metal:
Maximum serviceable limit:
Any amount, if in the limits of TASK 70-33-03-220-006 (SPECIAL INSPECTION FOR SURFACE FRETTING OR GALLING) .
Repair method:
Repair. Refer to TASK 72-31-44-300-803 (72-31-44, REPAIR 004).
Subtask 72-31-44-220-068
(2)Chipped or missing coating:
Maximum serviceable limit:
Any amount, any length, 0.003 inch (0.07 mm) in depth. Total length for all chipped or missing coating must not be more than 5 percent of the rabbet surface.
Repair method:
Repair. Refer to TASK 72-31-44-300-803 (72-31-44, REPAIR 004).
* * * FOR ALL
Figure 805   Definition of the Root Fillet
* * * FOR ALL
Figure 806   Examples of Tip Discoloration Caused by Tip Rub
* * * FOR ALL
Figure 807   Examples of Tip Contact Marks.
6 . Special Dimensional Inspection.
Subtask 72-31-44-220-059
A.Deleted.
Subtask 72-31-44-220-063
B.Measure all dimensions with surface X held flat to 0.003 inch (0.08 mm) and diameter Y held within 21.031-21.026 inches (534.19-534.06 mm).
Subtask 72-31-44-220-037
C.Measure the dimensions that follow:
(1)Dimension B:
NOTE:
Do this special dimensional inspection only if a visual inspection or other defect condition makes a dimensional inspection necessary. Refer to Figure 808.
Minimum serviceable limit:
1.37 inches (34.8 mm).
Repair method:
Replace the blisk.
* * * FOR ALL
Figure 808   (Sheet 1) Blisk - Dimensional Inspection
* * * FOR ALL
Figure 808   (Sheet 2) Blisk - Dimensional Inspection
Subtask 72-31-44-220-038
(2)Dimension LE:
NOTE:
Do this special dimensional inspection only if a visual inspection or other defect condition makes a dimensional inspection necessary. Refer to Figure 808.
Minimum serviceable limit:
0.012 inch (0.30 mm).
Repair method:
Replace the blisk.
Subtask 72-31-44-220-039
(3)Dimension TE:
NOTE:
Do this special dimensional inspection only if a visual inspection or other defect condition makes a dimensional inspection necessary. Refer to Figure 808.
Minimum serviceable limit:
0.014 inch (0.36 mm).
Repair method:
Replace the blisk.
Subtask 72-31-44-220-041
(4)Diameter Y:
Maximum serviceable limit:
21.031 inches (534.19 mm).
Repair method:
Repair. Refer to TASK 72-31-44-300-803 (72-31-44, REPAIR 004).
Subtask 72-31-44-220-042
(5)Diameter AZ:
Maximum serviceable limit:
21.081 inches (535.45 mm).
Repair method:
Repair. Refer to TASK 72-31-44-300-803 (72-31-44, REPAIR 004).
Subtask 72-31-44-220-060
D.Do an inspection of the height of the airfoil for:
NOTE:
Do this special dimensional inspection only if a visual inspection or other defect condition makes a dimensional inspection necessary. Refer to Figure 808.
(1)Radius TH1:
Minimum serviceable limit:
13.178 inches (334.72 mm).
Repair method:
Replace the blisk.
Subtask 72-31-44-220-061
(2)Radius TH2:
Minimum serviceable limit:
13.114 inches (333.10 mm).
Repair method:
Replace the blisk.
Subtask 72-31-44-220-062
(3)Radius TH3:
Minimum serviceable limit:
13.155 inches (334.14 mm).
Repair method:
Replace the blisk.