Appendix C
SAMPLE INSPECTION PROCEDURE ENGINE GENERAL - INSPECTION/CHECK-00 Task 72-00-00-990-004:
1. Preliminary Instructions CAUTION: TITANIUM WELDMENTS AND ASSEMBLIES SHOULD NOT BE
PROCESSED THROUGH TRICHLORETHYLENE DEGREASERS OR
ANY CLEANER CONTAINING CHLORIDES IN ORDER TO AVOID
POSSIBILITY OF STRESS CORROSION ASSOCIATED WITH
ENTRAPMENT OF CHLORINE-CONTAINING MATERIALS IN TIGHT FITTING AREAS. THIS RESTRICTION ALSO APPLIES TO
PARTS SUCH AS TITANIUM DISKS OR HUBS CONTAINING INSERTS, SLEEVES, OR PINS. DISKS MUST BE DEBLADED
PRIOR TO CLEANING AND PRIOR TO FLUORESCENT PENETRANT OR MAGNETIC PARTICLE INSPECTION.
Thorough and intelligent inspection of all engine parts is one of the controlling factors in efficient and dependable maintenance, and too much emphasis cannot be placed on the importance of careful inspection and the decisions it involves. Inspection personnel must be thoroughly familiar with instructions in this chapter, in the requirements of the Standard Practices Manual and in Repair Sections.
B. After engine is disassembled and cleaned, arrange all parts of engine on inspection table so that inspector can judge the condition of engine as a whole and can readily make reference to other engine parts which may have been affected by a worn part.
In this way, it will often be possible to determine at once the cause of any abnormal wear.
2. Records and Limits During inspection, keep a record of the condition of all parts and a record of all fits, clearances, and spring pressures. Refer to the specific fits and clearances requirements in the appropriate Inspection/Check sections of this manual for proper limits. Attach a tag, indicating that replacement is necessary, to any part which is found to be unfit for further service. Attach a tag describing necessary refurbisment to any part which requires repair. If refurbishment will affect a fit or clearance, tag must remain with part until final assembly and must be marked with a warning to check fit or clearance.
B. When a new part is to be installed and it is important that it be identified as to engine number or position in engine; mark it by appropriate method described in Marking of Parts in Standard Practices Manual.
C. When making out inspection records or reports, use only descriptive words which accurately qualify existing conditions. In order to eliminate confusion and to maintain consistent terminology, the various physical conditions and the determination of the usual causes of wear or damage to engine parts which might be encountered during inspection are defined in the Physical Inspection Section of Standard Practices a Manual.
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Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) ENGINE GENERAL - INSPECTION/CHECK-00 Task 72-00-00-990-004:
D. If inspection reveals it necessary to replace a fitted spacer, tag spacer to indicate that replacement must be made with a part of correct classification at assembly.
3. General Inspections A See Standard Practices Manual as follows:
(1) Physical Inspection
(2) Magnetic Particle Inspection
(3) Fluorescent Penetrant Inspection
(4) Surface Treatments
(5) Welding
(6) Gage Inspection Corrosion Prevention After Inspection Equipment and Materials:
Iter No. Designation P95-035 Corrosion Preventive Oil (AMS 3065) B. After inspection, whenever it is deemed that sufficient time will elapse before reassembly to allow damage to parts from corrosion, cover all unprotected surfaces of magnesium and steel parts, or any parts with which corrosion difficulties are experienced, with Corrosion Preventive Oil (P05-035). Unless the parts are otherwise preserved for longer periods of time, they should be recoated with Corrosion Prevention Oil (P05-035), every four days.
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Appendix C STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-00 Task 72-31-82-990-001:
1. Inspection/Check Part Number Index - State 1 LPC Blade Assembly Inspection Functional Arrangement
(1) Inspection/Check-01 through Inspection/Check-06 contain procedures for complete inspection of Stage 1 LPC blade assembly. Inspection function and applicability for this part are shown in Table 801.
INSPECTION/CHECK INSPECTION/CHECK INSPECTION/CHECK
NUMBER CATEGORY APPLICABILITY +0-1 Preinspection Applicable Preparation
- 0-2 Non-destructive Applicable inspection -03 Visual inspection Applicable -04 Dimensional Applicable Inspection
- 05 Functional Check Applicable Inspection -06 Inspection Applicable Postrequisites Inspection Functional Arrangement Table 801 B. Inspection/Check Part Number Index
(1) Table 802 is a listing of part numbers and appropriate Inspection/Check Referenced service bulletins are listed for parts introduced or obtained by service bulletin incorporation.
PART SERVICE
NUMBER INSPECTION/CHECK BULLETIN 52A121 01.02,03,04,06 PW4ENG 72-132 53A321 01,02,03,04,06 PW4ENG 72-132 Inspection/Check Part Number Index Table 802 Page 804 EFF: ALL Pee Page 4
8/14/97 AC 43-204 Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01 Task 72-31-82-990-002:
1. Preinspection Preparation - Stage 1 LPC Blade Assembly A Prerequisites
(1) See Inspection/Check-00 (Task 72-31-82-990-001) for functional arrangement and part number applicability.
B. Equipment and Materials Required • None C. Procedure See Figures 801, 802 and 803.
WARNING TO AVOID POSSIBLE INJURY TO HANDS, GLOVES SHOULD BE WORN WHEN HANDLING BLADES.
CAUTION: NICKS IN LEADING AND TRAINING EDGES BECOME
INCREASINGLY CRITICAL THE CLOSER THEY ARE TO ROOT OF BLADE. THEREFORE, ANY INJURY TO THAT
PORTION OF BLADE FROM PART SPAN SHROUD TO PLATFORM MUST BE TREATED WITH EXTREME CARE.
(1) Following instructions are standard inspection criteria which apply throughout inspection procedures.
Blade limits are evaluated from a standpoint of structural integrity.
The use of a substantial number of blades repaired to or near maximum limits, or use of blades having many repaired areas, may affect compressor efficiency and therefore engine performance.
(b) All blade surfaces must be smooth and all evidence of previous leading and trailing edge repairs should be smooth with a minimum edge thickness as shown in Figure 802 maintained.
(c) All blade limits are based on original edge contour, therefore, all blends in one location are cumulative. For example, if blend depth limit is made, no further blend nor the sum of several future blends may exceed the maximum blend depth at that location. Blends directly opposite one another on leading and trailing edge are also cumulative and must not exceed maximum depth of single leading or trailing edge blend.
(d) Maximum depth blends on leading and trailing edges must be separated by minimum distance equal to mean chordal length of blade.
See Figure 803.
rel Limits apply to damaged area after blending and not to magnitude of damage measured before blending.
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Appendix C STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01
- BLADE TIP
OUTER PORTION - PART SPAN SHROUD
OF BLADE -
SHROUD TO AIRFOIL RADIUS (4 PLACES)
FRONT AND REAR
LEADING EDGE SHROUD RADIUS
AREA (FOUR PLACES)
INNER PORTION OF BLADE • TRAILING EDGE
- PLATFORM TO AIRFOIL
RADIUS (ALL AROUND BLADE
AIRFOIL PLATFORM AND BLADE
ROOT SECTION ROOT SECTION
• PLATFORM SEAL Blade Area Nomenclature Figure 801 (Task 72-31-82-990-002) Page 802 EFF: ALL Page 6
Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01
SECTION A - A L-A0968 1285
1. Minimum Trailing Edge Thickness As Measured At Index 2 To Be 0.020 Inch (0.51 mm).
2. 0.040 Inch (1.02 mm) - Measure Leading And Trailing Edge Thickness At This Dimension
3. 12.229 Inch (310.617 mm) - Minimum Leading Edge Thickness As Measured At Index 2 To Be
0.038 Inch (0.965 mm).
4. Minimum Leading Edge Thickness As Measured At Index 2 To Be 0.027 Inch (0.686 mm).
Leading And Trailing Edge Minimum Thickness Limits Figure 802 (Task 72-31-82-990-002) Page 803 EFF: ALL Page 7
AC 43 - 204 8/14/97 Appendix C STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01 L-A0969 Mean Chordal Length Measured Equidistant Between Blends.
2. Blends Must Be separated By Minimum Dimension Equal To Index 1 Dimension.
Minimum Blend Separation Figure 803 (Task 72-31-82-990-002) Page 804 EFF: ALL Page 8
46/57/8 AC 43-204 Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01
(f) If two or more heavily blended blades are found grouped together, an attempt should be made to redistribute these blades and their matching blades evenly throughout rotor.
(g) Total Length of leading and trailing edge blends must not exceed four inches (101.600 mm) and there must not be more than two blends to maximum depth limit per blade.
(2) Visually check leading and trailing edges ofblade for damage whenever foreign NOTE: Use of strong lights and mirrors as well as fingernails and fingertips may aid in locating damaged areas.
CAUTION: USE EXTREME CAUTION WITH ANY ELECTRICAL EQUIP- MENT IN THE VICINITY OF BLADE. CONTACT WITH
ANY ELECTRICAL SOURCE THAT MAY PASS CURRENT TO BLADE SURFACE CAN CAUSE AN ARC BURN. ARC
BURN CAN RESULT IN LOCAL DEGRADATION MATERIAL PROPERTIES AND CRACK INITIATION.
(3) When checking blades for foreign object damage visually inspect for arc burn.
Arc burn is evidenced by a small circular or semi-circular bead affected area on blade surface that may contain shallow pitting, remelt or a crack. Blades with arc burn are not acceptable for further service.
(4) The following procedure is recommended for inspection of 1st stage blade assembly after refurbishment or repair.
Visually inspect blade using a bright light, mirrors, a 3X glass.
fingertips and fingernails, specifically looking for small depressions that interrupt surface contour. Refer to PWA Color Photographs for conditions that have been observed.
(b) Peening tends to remove evidence of heat discoloration and to smooth damage, making it less visually apparent.
(c) Electrical discharge damage has been observed in two different forms:
Strong geometric shapes such as ovals, crescents, or rectangles depressed into blade surface might be caused by contact with a rod or wire carrying an electrical charge.
Coarse linear indications, typically composed of small overlapping craters or pits.
NOTE: Regardless of form, damage is a local phenomenon.
unlike erosion pitting, and damage boundaries do not have raised material as does damage from foreign object damage.
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8/14/97 AC 43-204 Appendix C STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-01
(5) service immediately, and blue etch anodize-inspected to confirm damage. Blades suspected of having electrical discharge damage must be removed from CAUTION: ELECTRICAL DISCHARGE DAMAGE IS NOT REPAIRABLE BY BLENDING. THIS DAMAGE PRODUCES A HEAT AFFECTED AREA WHICH MAY EXTEND UP TO 0.060 INCH (1.524 MM) DEEPER THAN VISIBLE DAMAGE. ANY
BLADES EXHIBITING THIS DAMAGE SHOULD RETIRED FROM SERVICE.
(6) subsurface as well as surface damage is removed. It is critically important The blending procedures described herein are intended to ensure that all that the blending procedures be followed carefully whether performed in the shop or on the wing. Proper blending must be performed in successive stages:
Removal of the visible damage, confrmation by eddy current or fluorescent penetrant inspection that all surface damage has been removed and, finally, removal of additional material to ensure the removal or subsurface deformed D. Preparation For Inspection
(2) Disassemble and remove attached parts). Not Applicable
(2) Remove surface treatments - See Repair-06 (Task 72-31-82-300-006).
(3) Clean base material - See 72-31-00, Cleaning-01 (Task 72-31-00-100-001).
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Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-03 Task 72-31-82-200-003:
1. Visual Inspection - Stage 1 LPC Blade Assembly NOTE: Comply with the following procedures whenever foreign object damage is suspected.
Prerequisites
(1) See Inspection/Check-00 (Task 72-31-82-990-001) for functional arrangement
(2) See Inspection/Check-01 (Task 72-31-82-990-002) for general inspection data. and part number applicability.
B: Equipment And Materials Required - None
c. Inspect State 1 LPC Blade Assembly For Damage See Figures 801 through 803.
Inspect airfoil, except leading and trailing edges for damage. Following types of damage should be blended per repair-02 (Task 72-31-82-300-002) within limits specified in Figure 801.
NOTE: Limits shown in referenced figure refer to maximum material removal allowed during blending and not to actual depth of damage before blending. Damage at or near maximum limits shown will not be reparable if blending will exceed these limits.
(a) Sustained indentations with compressed material and raised edges.
(b) Injuries with small radii or ragged edges.
(c) Tip curl damage.
(2) Inspect leading and trailing edges for foreign object damage such as nicks and dents. These defects must be blended per Repair-02 (Task 72-31-82-300-002).
See Figures 801, 802 and 803. No cracks or tears are permitted.
(a) Damage, not within critical area, should be blended if it exceeds 0.020 inch (0.51 mm) depth.
(b) Damage, within critical area, should be blended if it exceeds 0.005 inch
(0.127 mm) in depth.
(c) Damage not exceeding 0.005 inch (0.127 mm) in depth need not be blended provided material is not torn.
D. Airfoil Root Section Blend Limits See Figure 803.
NOTE: Amount of material removed in previous blend repairs in root section is marked on blade platform as shown in Figure 804. Amount marked is total of all repairs either to leading or trailing edge and should be a consideration when determining if damage is reparable.
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Appendix C STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-03
PLANE Z
TANGENT -TANGENT 90° 13 SECTION A-A L-A1057
CHORD LENGTH MEASUREMENT Airfoil Inspection Limits Figure 801 (Task 72-31-82-200-003) Page 808 EFF: ALL Page 12
Appendix C Pratt & Whitney PW4000 SERIES ENGINE MANUAL (PN 50A443) STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-03 Blade Tip Blend Radius - 1.500 Inches (38.100 mm) Maximum.
2. Leading Or Trailing Edge And Tip Blend Area - Blend To Be 0.750 Inch (19.050 mm) Deep
3. 19.515 Inches (495.681 mm).
Critical Area - Depth Of Blend To Be 0.250 Inch (6.350 mm) Maximum Except For Airfoil Root Section. See Index 5 Dimension.
1.000 Inch (25.400 mm) - Damage In Airfoil-To-Platform Radius Area Cannot Be Blended Except Per Airfoil Root Section Blend Limits In Paragraph D.
6. No Damage Or Blending Permitted In Shroud-To-Airfoil Radius Or Platform-To-Airfoil Radius.
7. Concave And Convex Blade Surface Blend Area - Depth Of Blend In This Area To Be 0.030 Inch (0.762 mm) Maximum (Round Bottom).
8. Leading Edge Blend Area - Depth Of Blend To Be 0.500 Inch (12.77 mm) Maximum.
9. 6.300 Inches (160.020 mm)
10. 18.500 Inches (469.900 mm)
11. 22.500 Inches (571.800 mm)
12. 0.500 Inch (12.700 mm), Pour Places.
13. Minimum Chord Length To Be 6.950 Inches (176.530 mm) Within 6.390 Inches (160.020 mm) Of Leading Edge Platform. Chord Length Must Be Measured Tangent To Blade Leading And Trailing Edges And Parallel To Phase Z.
NOTE: Damage which affects both Index 1 and Index 2 must be blended by combining both limits to produce a smooth blend.
Key To Figure 801 Page 809 Page 13 (and 14)