SERVICE BULLETIN REVISION NOTICE

ENGINE — DISK, 15TH STAGE HIGH PRESSURE COMPRESSOR (HPC) — REPETITIVE

BORESCOPE INSPECTION OR EDDY CURRENT INSPECTION (ECI) FOR CRACKS IN THE

FRONT RAIL OF THE OUTER RIM

Turbojet Engine Service Bulletin No. PW4G-112-72-309 Revision No. 1 dated July 1, 2010.

Revision History

Original Issue November 10, 2009

Revision 1 dated July 1, 2010

Reason for the Revision

To update the number of cracks found in service engines to date from 41 to 53.

To revise the compliance to include a drawdown plan and limit disk life to 12,000 cycles.

To attach NDIP-1014, Revision B.

To remove “There is no terminating action for this repetitive inspection at this time.”.

To remove “NOTE: Engine Serial No. P777032 and P777038 were inspected and meet the initial

inspection requirement of this Service Bulletin” from the Effectivity section.

Effect of Revision on Prior Compliance

None.

This is a Complete Revision (Not Applicable to the SGML version)

The contents are in accordance with the list of effective pages. All pages have the current revision

number. Technical changes are marked with black bars.

Non-Destructive Inspection Procedures

NDIP-1014, Revision B dated June 7, 2010 is attached. Please discard the previously issued copy.

MODEL APPLICATION

PW4074, PW4077

BULLETIN ISSUE SEQUENCE

PW4G-112 Series 72-309

Page Revision No. Date

1 thru 18 1 July 1/10

A copy of this Revision Notice and any future revision notices must be filed as a permanent

record with your copy of the subject bulletin.

P&W Distribution Code

2641, 2648 PW4G-112-72-309

Page 1 of 1

Printed in United States of America
SERVICE BULLETIN

ENGINE — DISK, 15TH STAGE HIGH PRESSURE COMPRESSOR (HPC) —

REPETITIVE BORESCOPE INSPECTION OR EDDY CURRENT INSPECTION (ECI)

FOR CRACKS IN THE FRONT RAIL OF THE OUTER RIM

MODEL APPLICATION

PW4074, PW4077

BULLETIN ISSUE SEQUENCE

PW4G-112 Series 72-309

ATA NUMBER

72-35-00

UTC/P&W PROPRIETARY INFORMATION

This document is the property of United Technologies Corporation — Pratt & Whitney (UTC/P&W). You may not possess,

use, copy or disclose this document or any information in it, for any purpose, including without limitation to design,

manufacture, or repair parts, or obtain FAA or other government approval to do so, without UTC/P&W’s express written

permission. Neither receipt nor possession of this document alone, from any source, constitutes such permission.

Possession, use, copying or disclosure by anyone without UTC/P&W’s express written permission is not authorized

and may result in criminal and/or civil liability.

Compliance Category

3

P&W Distribution Code

2641, 2648

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Printed in United States of America
Summary

The purpose of this Service Bulletin is to provide instructions to do a repetitive borescope inspection

or Eddy Current Inspection (ECI) of the 15th stage High Pressure Compressor (HPC) disk for cracks.

Inspection of 15th stage disks of in service engines found 53 cracks in the front rail of the blade

loading and/or locking slots on the outer rim. Metallurgical examination of the 15th stage HPC disk

cracks revealed that the initiation was the result of Thermal Mechanical Fatigue (TMF). Remove

from service any disk that has a crack. The ECI is in NDIP-1014 Revision B and is provided in

the Appendix section of this Service Bulletin.

Planning Information

Effectivity Data

Engine Models Applicable

PW4074, PW4077

Engine Serial No. — All engines that have 15th Stage HPC Disk, PN 55H615 installed.

Concurrent Requirements

There are no concurrent requirements.

Reason

1. Problem: Inspection of 15th stage disks of in service engines found 53 cracks in the

front rail of the blade loading and/or locking slots on the outer rim.

2. Cause: Metallurgical examination of the cracks revealed that the initiation was the

result of TMF.

3. Solution: Do a repetitive borescope inspection or ECI of the 15th stage HPC disk.

Description

Do a borescope inspection or ECI of the 15th stage HPC disk.

Compliance

Category 3

15th stage HPC Disks, PN 55H615 with 12,000 part cycles since new must be removed

from service.

For engines with disks that have accumulated less than or equal to 9,865 cycles when this

Service Bulletin is released, the engine must be removed when the 15th disk accumulates

12,000 cycles since new. For engines with disks that have accumulated more than 9,865

cycles when this Service Bulletin is released, the engine must be removed by 2,135

cycles after Service Bulletin release. If a disk exceeds 12,000 cycles since new before

the engine is removed, perform an inspection of the disk before 12,000 cycles, and

repeat the inspection before 1,200 additional cycles until the disk is removed within 2,135

cycles, or a crack is found. The repeat inspection is waived if the previous inspection was

accomplished with ECI.

NOTE: FPI can be done as specified in Reference 4, CIR Manual, Chapter/Section

72-35-92, Inspection/Check-02 or Reference 6, Service Bulletin No.

PW4G-112-72-243.

ECI can be done as specified in Reference 7, NDIP-1014 Revision B. NDIP-1014

Revision B is provided in the Appendix section of this Service Bulletin.

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
If a crack is suspected by borescope inspection, but cannot be visually confirmed, do an

ECI within 5 cycles.

Approval Data

The times between inspections specified in Compliance and the inspection procedures

specified in the Accomplishment Instructions agree with the applicable Federal Aviation

Regulations and are FAA-Approved for the engine model(s) given.

Manpower

The estimate of man-hours of labor directly necessary to do the intent of this Service

Bulletin are as follows:

For Engines Installed On The Aircraft

1. Open and Close Cowl Doors ............................................................................. 0.5

2. Necessary to do the Inspection .......................................................................... 2.5

3. Total Necessary Man-hours ............................................................................... 3.0

For Engines Removed From The Aircraft

1. Necessary to do the Inspection .......................................................................... 2.5

2. Total Necessary Man-hours ............................................................................... 2.5

Weight Data

No Change.

Electrical Load Data

Not Applicable.

Software Accomplishment Summary

Not Applicable.

References

1. Turbojet Engine Standard Practices Manual, Part No. 585005.

2. PW4074, PW4077 Turbofan Engines, Illustrated Parts Catalog, Part No. 51A346.

3. PW4074, PW4077 Turbofan Engines, Engine Manual, Part No. 51A345.

4. PW4000 Series 112 Inch PW4074, PW4077, PW4077D, PW4084D, PW4090, PW4098

Turbofan Engines, Engine Cleaning, Inspection And Repair (CIR) Manual, Part No.

51A750.

5. Boeing 777 Aircraft Maintenance Manual.

6. Service Bulletin No. PW4G-112-72-243; Engine — Disk, 15Th Stage High Pressure

Compressor (HPC) — Inspection For Cracks In The Blade Slot Loading And Locking

Locations And Knife Edge Seal Location. Issue Sequence 72-243, PW4G-112 Series.

7. Non-Destructive Inspection Procedure NDIP-1014, Revision B, — PW4074 / PW4077

15th Stage HPC Disk Front Rail Blade Loading Slot and Locking Areas Eddy Current

Inspections (Assembled/Aircraft Installed).

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
Publications Changed

Not Applicable.

Interchangeability

Not Applicable.

Information in the Appendix

Alternate Accomplishment Instructions (No)

Progression Charts (No)

Added Data (Yes)

Revision to Table of Limits (No)

Inspection Procedures (No)

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
Material Information

Material — Cost and Availability

1. The estimated price to do the Borescope Inspection procedure in this Service Bulletin is

$12.90 for a new borescope plug key washer.

2. There is no kit provided to do this Service Bulletin.

3. Part availability information is provided in material data Instructions — Disposition.

Industry Support Program

Not Applicable.

The material data that follows is for each engine.

NOTE: It is possible to use the Chapter/Section and Figure/Item reference number

shown below the old part number to find the part in the Illustrated Parts Catalog.

CAUTION: THE FOLLOWING MATERIAL DATA TABLE(S) ARE ORGANIZED BY

ILLUSTRATED PARTS CATALOG. ALL PARTS IN THE TABLE(S) MAY OR

MAY NOT BE APPLICABLE TO ALL THE ENGINE MODELS SHOWN

IN THE TABLE HEADING. YOU MUST REFER TO THE APPROPRIATE

ILLUSTRATED PARTS CATALOG FOR ENGINE MODEL APPLICABILITY

USING THE OLD PART NUMBER (PN) AND CATALOG SEQUENCE

NUMBER. FAILURE TO INSTALL THE PART(S) IN THE CORRECT

ENGINE MODEL MAY RESULT IN A CONFIGURATION THAT IS NOT FAA

APPROVED.

The material data that follows is for each engine.

For PW4074, PW4077 Engines:

New PN Qty Estimate of Unit

Price ($)

Keyword Old PN Instructions —

Disposition

1 DISK — HPC,

15STG

55H615

(72-35-00-1-210)

(4)(X)

58H216 1 12.90 KEY WASHER 58H216

(72-35-00-25-20 A)

(E)

Modification and Spares Information

Estimated part prices are provided when they are available at time of publication. The

Estimate of Unit Price is only for planning purposes and does not constitute a firm

quotation. An asterisk (*) is shown where part pricing information was unavailable. In either

case, contact Pratt & Whitney Spares Management & Logistics for firm quotations.

Parts Modification Conditions

(4) Do an inspection as specified in the Accomplishment Instructions.

Spare Parts Availability

(E) The part is an expendable item necessary to do this bulletin.

(X) See Reference 2, Illustrated Parts Catalog for applicable replacement parts.

Cleaning, Inspection and Repair Information

Not Applicable.

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
Vendor Services or Special Components/Materials

Not Applicable.

Material Data for Each Spare Engine

The material for each spare engine is as stated in the preceding material information

section.

Reidentified Parts

Not Applicable.

Necessary Tools

New Support Equipment that is necessary

Tool No. Name

Standard Flexible borescope with articulating tip

and 150 watt minimum light source. (A

4mm flexible borescope is recommended;

however, other size flexible borescopes

can be used if the viewing quality is

the same or better than a 4mm flexible

borescope.)

PWA 88247 Rotator

(Or equivalent as specified in Reference 5,

Aircraft Maintenance Manual)

Other Material Information Data

Not Applicable.

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REVISION NO. 1 - July 1/10 Page 6

UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
Accomplishment Instructions

NOTE: Service Bulletin incorporation on engines installed on aircraft may be desirable and

should be individually evaluated.

FOR ENGINES INSTALLED ON THE AIRCRAFT

1. Do an inspection of the 15th Stage Disk, PN 55H615 by one of the procedures that follow.

See Figure 1.

A. Do an ECI of the disk as specified in Reference 7, NDIP-1014 Revision B. NDIP-1014

Revision B is provided in the Appendix section of this Service Bulletin.

Or

B. Do a borescope inspection of the disk as follows:

(1) Open fan cowl doors and thrust reversers as specified in Reference 5, Aircraft

Maintenance Manual, Chapter/Section 71-11-04 and 78-31-00.

NOTE: The variable vanes must be fully open when the engine is shutdown.

If the vanes are not open use a large wrench or a crows foot wrench

to rotate the bellcrank on the stator vane actuator to the fully open

position.

(2) Access the disk through the AP-7 (borescope) port as specified in the

Reference 5, Aircraft Maintenance Manual, Chapter/Section 72-00-00. See

Figure 2, Sheets 1 and 2.

(3) Insert the borescope into the AP-7 port to view the front rail of the disk. See

Figure 2, Sheets 3 and 4.

(4) Remove the gearbox crank pad cover and use a PWA 88247 Rotator or

equivalent to rotate the rotor at the gearbox crank pad.

(5) Rotate the rotor until the first blade lock is seen. Use the blade lock locations

for angular reference. See Figure 3.

(6) Rotate the rotor in the same direction past two additional blades. If another

blade lock is found just past the second blade then the current location is a

lock and loading location. The loading slot (which is not visible) is between the

two blade locks. See Figure 3.

(7) Do an inspection of the front rail in the areas adjacent to the locking slots and the

area between the two locking slots for cracks. Cracks typically run in the radially

inboard direction from the outer rim of the rail. See Figure 2, Sheet 4.

(8) If another blade lock is not found just past the second blade, then the present

location is a blade lock only. See Figure 3.

(9) Do an inspection of the front rail for cracks adjacent to the blade lock. Cracks

typically run in the radially inboard direction from the outer rim of the rail. See

Figure 2, Sheet 4.

(10) Rotate the rotor until the next blade lock is visible and do the inspection of the

two blade lock and loading areas and four blade lock areas.

NOTE: Rotating the crack pad 360 degrees represents more than 360 degrees

of rotor rotation.

(11) The inspection criteria is as follows:

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
(a) If the disk does not have a crack, the disk is acceptable.

(b) If the disk does have a crack, replace the disk.

(c) If a crack is suspected, but cannot be visually confirmed, do an ECI within

5 cycles, as specified in Reference 7, NDIP-1014 Revision B. NDIP-1014

Revision B is provided in the Appendix section of this Service Bulletin.

(12) Remove the borescope and install the AP-7 borescope plug and new Key

Washer, PN 58H216 as specified in Reference 5, Aircraft Maintenance Manual,

Chapter/Section 72-00-00.

(13) Remove the PWA 88247 Rotator or equivalent and install the gearbox crank

pad cover.

(14) Close fan cowl doors and thrust reversers as specified in Reference 5, Aircraft

Maintenance Manual, Chapter/Section 71-11-04 and 78-31-00.

(15) Record the inspection results. For all disks that have cracks: operators are

requested to provide the results of the inspection to their local Pratt & Whitney

service representative. See Figure 4 for the data retrieval form.

FOR ENGINES REMOVED FROM THE AIRCRAFT (ASSEMBLED ENGINES AND/OR HPC

MODULES NOT SCHEDULED FOR DISASSEMBLY OR INSPECTION)

1. Do an inspection of the 15th stage disk, PN 55H615 by one of the procedures that follow.

See Figure 1.

NOTE: This inspection does not supersede or replace Reference 6, Service Bulletin No.

PW4G-112-72-243. This procedure is intended for assembled engines and/or

HPC modules not scheduled for disassembly or inspection as specified by

Reference 4, CIR Manual, Chapter/Section 72-35-92, Inspection/Check-02 or

Reference 6, Service Bulletin No. PW4G-112-72-243.

A. Do an ECI of the disk as specified in Reference 7, NDIP-1014, Revision B. NDIP-1014,

Revision B is provided in the Appendix section of this Service Bulletin.

or

B. Do a borescope inspection of the disk as follows:

(1) Access the disk through the AP-7 (borescope) port as specified in the

Reference 3, Engine Manual, Chapter/Section 72-00-00, Inspection/Check-03.

See Figure 2, Sheets 1 and 2.

NOTE: The variable vanes must be fully open when the engine is shutdown.

If the vanes are not open use a large wrench or a crows foot wrench

to rotate the bellcrank on the stator vane actuator to the fully open

position.

(2) Insert the borescope into the AP-7 port to view the front rail of the disk. See

Figure 2, Sheets 3 and 4.

(3) Remove the gearbox crank pad cover and use a PWA 88247 Rotator or

equivalent to rotate the rotor at the gearbox crank pad.

(4) Rotate the rotor until the first blade lock is seen. Use the blade lock locations

for angular reference. See Figure 3.

(5) Rotate the rotor in the same direction past two additional blades. If another

blade lock is found just past the second blade then the current location is a

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REVISION NO. 1 - July 1/10 Page 8

UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
lock and loading location. The loading slot (which is not visible) is between the

two blade locks. See Figure 3.

(6) Do an inspection of the front rail in the areas adjacent to the locking slots and the

area between the two locking slots for cracks. Cracks typically run in the radially

inboard direction from the outer rim of the rail. See Figure 2, Sheet 4.

(7) If another blade lock is not found just past the second blade, then the location is

a blade lock only. See Figure 3.

(8) Do an inspection of the front rail for cracks adjacent to the blade lock. Cracks

typically run in the radially inboard direction from the outer rim of the rail. See

Figure 2, Sheet 4.

(9) Rotate the rotor until the next blade lock is visible and do the inspection of the

two blade lock and loading areas and four blade lock areas.

NOTE: Rotating the crack pad 360 degrees represents more than 360 degrees

of rotor rotation.

(10) The inspection criteria is as follows:

(a) If the disk does not have a crack, the disk is acceptable.

(b) If the disk does have a crack, replace the disk.

(c) If a crack is suspected, but cannot be visually confirmed, do an ECI within

5 cycles, as specified in Reference 7, NDIP-1014 Revision B. NDIP-1014

Revision B is provided in the Appendix section of this Service Bulletin.

(11) Remove the borescope and install the AP-7 borescope plug and new

Key Washer, PN 58H216 as specified in Reference 3, Engine Manual,

Chapter/Section 72-00-00, Inspection/Check-03.

(12) Remove the PWA 88247 Rotator or equivalent and install the gearbox crank

pad cover.

(13) Record the inspection results. For all disks that have cracks: operators are

requested to provide the results of the inspection to their local Pratt & Whitney

service representative. See Figure 4 for the data retrieval form.

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
LOCATION OF THE 15TH STAGE HPC DISK

72-35-00

FIGURE 1

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
INSPECTION OF THE 15TH STAGE HPC DISK

FIGURE 2, SHEET 1

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
INSPECTION OF THE 15TH STAGE HPC DISK

FIGURE 2, SHEET 2

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
INSPECTION OF THE 15TH STAGE HPC DISK

FIGURE 2, SHEET 3

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REVISION NO. 1 - July 1/10 Page 13

UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
INSPECTION OF THE 15TH STAGE HPC DISK

FIGURE 2, SHEET 4

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
TYPICAL VIEW OF BLADE LOADING SLOT AREAS

FIGURE 3

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
DATA RETRIEVAL FORM

FIGURE 4

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
Appendix

Added Data

Internal Reference Information

Revision No.

Reference

Document

Origination

Original

EA09KA050

EA09KCC43

DB/IEL

1 EA09KCC43 DB/JEJ

Non-Destructive Inspection Procedure NDIP-1014, Revision B follows:

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UTC/P&W PROPRIETARY INFORMATION

Subject to the restrictions on the cover or first page.
NDIP-1014 REV. B Effective 06/07/2010

1

PW4074 / PW4077 

15th Stage HPC Disk 

Front Rail Blade Loading Slot and Locking Areas 

Eddy Current Inspections 

(Assembled/Aircraft Installed) 

NDIP–1014 

REVISION B

WARNING 

THIS DOCUMENT MAY CONTAIN INFORMATION SUBJECT TO THE INTERNATIONAL TRAFFIC IN ARMS REGULATION (ITAR) OR THE EXPORT 

ADMINISTRATION REGULATION (EAR) OF 1979. THIS INFORMATION MAY NOT BE EXPORTED, RELEASED, OR DISCLOSED TO FOREIGN 

NATIONALS OUTSIDE THE UNITED STATES WITHOUT FIRST COMPLYING WITH THE EXPORT LICENSE REQUIREMENTS OF THE 

INTERNATIONAL TRAFFIC IN ARMS REGULATION (ITAR) AND/OR THE EXPORT ADMINISTRATION REGULATION (EAR). A VIOLATION OF THE 

ITAR OR EAR MAY BE SUBJECT TO A PENALTY OF UP TO 10 YEARS IMPRISONMENT AND A FINE OF $1,000,000 UNDER 22 U.S.C 2778 OR 

SECTION 2410 OF THE EXPORT ADMINISTRATION ACT OF 1979. INCLUDE THIS NOTICE WITH ANY REPRODUCED PORTION OF THIS 

DOCUMENT. 

RESTRICTION 

PAGES OF THIS DOCUMENT MARKED WITH THE NOTICES SET FORTH BELOW CONTAIN CONTRACTOR COMPETITION SENSITIVE DATA 

AND/OR PRATT & WHITNEY PROPRIETARY DATA WHICH IS SUBMITTED IN CONFIDENCE. NO DISCLOSURE OR USE OF THIS INFORMATION 

IS PERMISSIBLE WITHOUT PRIOR WRITTEN CONSENT OF UNITED TECHNOLOGIES CORPORATION EXCEPT FOR OFFICIAL PURPOSES 

WITHIN THE U.S. GOVERNMENT. 

DOCUMENT PROPERTY RIGHTS NOTICE 

THIS DOCUMENT IS THE PROPERTY OF UNITED TECHNOLOGIES CORPORATION (UTC). YOU MAY NOT POSSESS, USE, COPY OR 

DISCLOSE THIS DOCUMENT OR ANY INFORMATION IN IT, FOR ANY PURPOSE, INCLUDING WITHOUT LIMITATION TO DESIGN, 

MANUFACTURE OR REPAIR PARTS, OR OBTAIN FAA OR OTHER GOVERNMENT APPROVAL TO DO SO, WITHOUT UTC’S EXPRESS WRITTEN 

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POSSESSION, USE, COPYRIGHT OR DISCLOSURE BY ANYONE WITHOUT UTC’S EXPRESS WRITTEN PERMISSION IS NOT AUTHORIZED AND 

MAY RESULT IN CRIMINAL AND OR CIVIL LIABILITY. 

NOTICES 

P&W PROPRIETARY INFORMATION ECCN 9E991 - EXPORT CONTROLLED 
NDIP-1014 REV. B Effective 06/07/2010

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 

2

PW4074 / PW4077 

15th Stage HPC Disk 

Front Rail Blade Loading Slot and Locking Areas 

Eddy Current Inspections 

(Assembled/Aircraft Installed) 

NDIP–1014 Revision B 

Issue Date: June 07, 2010 

Written By: Wenji Peng 

Approved By: Jonathan Sullivan PL3

Instructions described within this procedure do not replace, amend or supersede any instructions 

included in other Pratt & Whitney technical publications. Active Service Bulletins and other 

technical publications published by Pratt & Whitney comprise approved technical data. 

The purpose of Revision A: 1. Apply this procedure only to engine models PW4074 / PW4077. 2. 

Add the requirements of eddy current inspections on all blade loading and locking areas of 15th 

stage HPC disk front rail. 

The purpose of revision B: Remove Figure 4, in which the AP7 and gear box locations have 

already been depicted and described in page 11-13 of the revision of Service Bulletins PW4G-112-

72-309, from NDIP-1014 A. 
NDIP-1014 REV. B Effective 06/07/2010

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 

3

PW4074 / PW4077 

15th Stage HPC Disk 

Front Rail Blade Loading Slot and Blade Locking Areas 

Eddy Current Inspections 

(Assembled/Aircraft Installed) 

I. GENERAL 

The objective of this eddy current inspection is to verify crack indications in the front rail at 

the blade loading slot or blade locking areas of the 15th stage high pressure compressor 

(HPC) disk for the PW4074/PW4077 engine models. The inspection is conducted on 

assembled engines and may be applied to an aircraft installed engine. 

The inspection is accomplished by inserting and manipulating an eddy current probe 

assembly through the AP-7 borescope access port to place the probe tip in contact with the 

front rail, and then rotating the HPC rotor to traverse the blade loading slot or blade 

locking area(s) past the probe. A borescope is in the AP-7 borescope access port alongside 

the probe assembly to visually aid in the placement of the eddy current probe and 

verification of proper probe position during inspection. 

This manual is provided as an inspection training guide. 
NDIP-1014 REV. B Effective 06/07/2010

II. ACCOMPLISHMENT INSTRUCTIONS 

 A. EQUIPMENT REQUIRED, Figure 1.

FIGURE 1 

EQUIPMENT REQUIRED 

4

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 
NDIP-1014 REV. B Effective 06/07/2010

1. PWA 105249, Eddy Current Probe Assembly, Figure 2. 

FIGURE 2 

PWA 105249 EDDY CURRENT PROBE ASSEMBLY 

NOTE: The PWA 105249 eddy current probe assembly consists of an absolute 

coil at the tip of a shaft attached to a handle with the electrical cables 

located within the shaft. 

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 

5
NDIP-1014 REV. B Effective 06/07/2010

2. PWA 26964 Sensitivity Setting Standard, Figure 3. 

FIGURE 3 

PWA 26964 SENSITIVITY SETTING STANDARD 

NOTE: The PWA 26964 sensitivity setting standard consists a flat plate with a 

simulated defect, 0.750 inch (19.1 mm) long by 0.025 inch (0.64 mm) 

deep by 0.010 inch (0.25 mm) wide, electro-discharged machined into 

the surface

6 

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 
NDIP-1014 REV. B Effective 06/07/2010

Pratt & Whitney Proprietary Information – ECCN 9E991 

Use or disclosure of the data contained in this sheet is subject to the restriction on the title page of this document 

7

3. Eddy Current Instrument, Foerster Defectometer® Model H 2.835 or equivalent — available 

from: 

Foerster Instruments 

Inc. RIDC Park West 

140 Industry Drive 

Pittsburgh, PA 

15275 U.S.A. 

or Institut Dr. Friedrich Forster 

Prufgeratebau GmbH & Co. KG In 

Laisen 70 

D-7410 Reutlingen 

Germany 

NOTE: This inspection uses an eddy current instrument operating at 

a frequency of 2 MHz. 

NOTE: The equipment described in this procedure is consistent with the 

listed requirements but is not intended to prevent the use of alternate 

equivalent eddy current instruments. 

NOTE: The operating manual for the eddy current instrument applied to 

this inspection should be referenced to obtain a complete understanding of 

instrument operating procedure. 

4. Oscillographic Recorder, Yokogawa OR100 or equivalent — available from: 

Yokogawa Electric Corp. or Yokogawa Corp. of America 

2 Dart Road 9-32, Nakacho 2-chome 

Shenandoah Industrial Musashino-shi 

Newman, GA 302650 Tokyo 18 

U.S.A. Japan 

NOTE: This inspection uses an oscillographic recorder operating at a chart speed 

of 2 seconds per division with an input amplifier gain set to 0.5 volts per division. 

The equipment described in this procedure is consistent with the listed 

requirements but is not intended to prevent the use of alternate equivalent 

recorders. 

NOTE: The operating manual for the recorder applied to this inspection should 

be referenced to obtain a complete understanding of recorder operating procedure. 

5. Patch Cord, Defectometer® H 2.835 to Yokogawa OR100 or equivalent. Purchase from 

the eddy current instrument manufacturer or fabricate locally. Refer to instrument and 

recorder operating manuals for wiring diagrams and appropriate connectors. 

6. Borescope, Flexible, 0.181 inch (4 mm) maximum diameter by 39 inches (100 cm) 

long, direct view, 50 degree minimum field of view, Machida FBA-4D-100, or equivalent 

— available from: 

Machida, Inc. 

40 Ramland Road 

Orangeburg, NY 10962 

U.S.A. 

www.machidascope.com
NDIP-1014 REV. B Effective 06/07/2010

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8

7. Light Source, Model LB-24, 24 watt xenon or equivalent — available from: 

Machida, Inc. 

40 Ramland Road 

Orangeburg, NY 10962 

U.S.A. 

www.machidascope.com

NOTE: The operating manual for the Model LB-24 light source applied to this 

inspection should be read to obtain a familiarization with the light source 

operating procedure. 

8. Magic Arm Assembly, Bogen Model 2930-Art #143A, with two (2) Super Clamps, Bogen 

Model 2900-Art. #035 — available from: 

Bogen Photo Corporation 

565 East Crescent Avenue 

P.O. Box 506 

Ramsey, NJ 07446-0506 

U.S.A. 

www.bogenphoto.com

info@bogenphoto.com

or Manfrotto & Co. Italy 

9. Engine Turning Tool — Breaker bar with spline socket. 

NOTE: It is acceptable to use a motorized engine turning tool, SMI Model TT-70 or 

equivalent — available from: 

Machida, Inc. 

40 Ramland Road 

Orangeburg, NY 10962 U.S.A. 

www.machidascope.com

10. Low Friction Tape, 3M Electrical Tape, Scotch® #60-1/4, 0.003 inch (0.08 mm) thick 

adhesive backed or equivalent — available from: 

3M 

St. Paul, MN 55144 

U.S.A. 

NOTE: Low friction tape is used to cover the probe coil area to minimize probe wear 

and to provide a low friction contact surface between the probe and the 15th 

stage HPC disk front rail surface. 

11. Refer to the similar Instructional Videotape, PN 01V039, “PW4090/PW4098 15th 

Stage HPC Disk Borescope and Eddy Current On-Wing Inspections′′. 
NDIP-1014 REV. B Effective 06/07/2010

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B. INSPECTOR QUALIFICATION/TRAINING REQUIREMENT 

CAUTION: INSPECTION PERSONNEL PERFORMING THE EDDY CURRENT 

INSPECTION PER NDIP-1014 MUST MEET THE FOLLOWING 

REQUIREMENTS: 

• MUST HAVE EXPERIENCE IN EDDY CURRENT INSPECTION 

THEORY AND APPLICATION PER THE INTERNAL REQUIREMENTS OF 

THE OPERATOR/OVERHAUL FACILITY, OR EQUIVALENT TO THE 

NAS-410 LEVEL II REQUIREMENTS; AND 

• SHOULD VIEW THE SIMILAR INSTRUCTIONAL VIDEOTAPE, PN 

01V039, “PW4090/PW4098 15TH STAGE HPC DISK BORESCOPE AND 

EDDY CURRENT ON-WING INSPECTIONS′′ TO OBTAIN A 

FAMILIARIZATION WITH THE INSPECTION APPLICATION. 

C. AIRFRAME/ENGINE PREPARATION 

CAUTION: THIS INSPECTION IS CONDUCTED ON AN ASSEMBLED 

ENGINE AND ON AN AIRCRAFT INSTALLED ENGINE. 

EVERY PRECAUTION MUST BE TAKEN TO INSURE THE 

INSPECTION IS CONDUCTED IN A SAFE MANNER TO 

PREVENT ACCIDENT OR INJURY. 

NOTE: The engine must cool down for a minimum of 4 hours prior to the inspection to 

allow the HPC area to achieve a temperature equal to or less than 150 degrees 

Fahrenheit (65 degrees Celsius). 

CAUTION: APPLICATION OF THE INSPECTION TO AN ENGINE WITH AN HPC 

TEMPERATURE OF GREATER THAN 150 DEGREES 

FAHRENHEIT (65 DEGREES CELSIUS) WILL DAMAGE THE PWA 

105249 EDDY CURRENT PROBE ASSEMBLYAND/OR PROVIDE 

ERRONEOUS EDDY CURRENT INSPECTION RESULTS. 

 1. Close the thrust reverser and open the cowl panels as required to obtain access to 

the AP-7 borescope access port and gearbox. 

 2. Remove AP-7 borescope access port plug and sleeve. 

3. Remove the gearbox crank pad cover and install engine rotating device. 

4. Position and secure inspection equipment in locations convenient to the AP-7 

borescope access port which will allow comfortable viewing during inspection and 

connection of power cords, connecting cables and light guide. 
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5. Attach and secure the magic arm assembly at an appropriate location on the 

engine. 

CAUTION: IT IS IMPORTANT TO ATTACH THE MAGIC ARM ASSEMBLY ON AN 

EXTERNAL COMPONENT THAT WILL NOT BE DAMAGED BY THE 

ATTACHMENT CLAMP. 

6. Set the magic arm assembly in a position that will hold the borescope and allow 

placement of the borescope in the AP-7 borescope access port without 

interference with external engine components and set the locking lever. 

7. Assemble the borescope. 

a. Attach the light guide of the borescope to the light source. 

b. Place the section of the borescope control body away from the focusing and 

articulating controls into the clamp of the magic arm assembly and secure. 

8. Turn on the light source. 

D. CALIBRATION PROCEDURE 

NOTE: The instructions described in these instructions are based on the 

Defectometer® H 2.835 eddy current instrument. 

If an equivalent eddy current instrument is used, the system application and 

control settings should be adjusted to duplicate the Defectometer® H 2.835 

instrument parameters described in this procedure. 

1. Carefully cover the probe coil contact surfaces of the PWA 105249 eddy current probe 

assembly with a smooth and wrinkle-free layer of low friction tape. 

NOTE: Check the low friction tape for damage prior to calibration and inspection and 

replace if damage is noted. It is necessary to conduct the calibration procedure 

after replacement of the teflon tape. 

2. Connect the probe cable to the Defectometer® H 2.835 eddy current instrument. 

3. Connect the eddy current instrument to the oscillographic recorder using the patch 

cord. 

4. Turn on the eddy current instrument. 
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11

5. Select the Fe mode by depressing and releasing the Material (M) button until Fe appears on 

the LCD panel. 

6. Turn on the oscillographic recorder. 

7. Set controls of oscillographic recorder as follows: 

Speed — 2 second/division 

Range — 0.5 Volts/division 

8. Perform the lift-off compensation procedure using the PWA 26964 sensitivity setting 

standard, Figure 4. 

FIGURE 4 

POSITION OF PWA 105249 EDDY CURRENT PROBE ASSEMBLY ON PWA 26964 

SENSITIVITY SETTING STANDARD DURING LIFT-OFF COMPENSATION PROCEDURE 
NDIP-1014 REV. B Effective 06/07/2010

a. With the coil end of the probe approximately 2 inches (51 mm) away from the 

sensitivity setting standard and any other electrically conductive or 

magnetically permeable material or magnetic field, depress the Lift-Off (L) 

button. 

b. After the Z indicator on the LCD panel starts to flash, place the coil end of the 

probe perpendicular to and on the inspection surface of the standard at a 

location midway between the edges and the simulated defect. 

c. Apply a load to the probe to contact the surface of the standard and 

depress the Zero (Z) button. 

9. Set the inspection sensitivity, Figure 5. 

FIGURE 5 

POSITION OF PWA 105249 EDDY CURRENT PROBE ASSEMBLY ON PWA 26964 

SENSITIVITY SETTING STANDARD DURING SENSITIVITY SETTING 

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NDIP-1014 REV. B Effective 06/07/2010

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a. Slowly traverse the probe along the standard while monitoring the recorder 

for the eddy current indication (rapid upscale and return pen movement) from 

the simulated defect, Figure 6. 

FIGURE 6 

TYPICAL RECORDER TRACE OF EDDY CURRENT INDICATION FROM THE SIMULATED 

DEFECT ON THE PWA 26964 SENSITIVITY SETTING STANDARD DURING CALIBRATION 

1) Maintain the coil perpendicular to the standard and traverse the probe across 

the simulated defect at a constant speed of approximately 0.5 inch (12.7 mm) 

per second. 

b. The recorder trace will exhibit a rapid upscale and return pen movement as the 

probe traverses over the simulated defect. 

c. Adjust the eddy current instrument and/or recorder gain control to reproduce the 

recorder trace and amplitude provided on the back of the certification card. 

d. Turn off the oscillographic recorder. 

NOTE: The calibration procedure using the PWA 105249 eddy current probe assembly and 

PWA 26964 sensitivity setting standard should be conducted at the beginning and 

end of each inspection sequence and whenever the inspection has been 

interrupted to maintain accurate inspection results.
NDIP-1014 REV. B Effective 6-2-10

E. INSPECTION PROCEDURE 

FIGURE 7 

BLADE LOADING SLOT and Blade Lock AREAS 

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NDIP-1014 REV. B Effective 6-2-10

1. Carefully insert and manipulate the articulating end of the borescope into the AP-7 

borescope access port. The location distribution of the blade loading slot or locking 

areas to be inspected is referred to Figure 7. 

a. Manipulate the borescope to obtain the view required for inspection, Figure 8a and 8b. 

FIGURE 8a 

A TYPICAL INSPECTION VIEW SHOWING BLADE LOADING SLOT AREA 

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NDIP-1014 REV. B Effective 06/07/2010

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FIGURE 8b 

A TYPICAL INSPECTION VIEW SHOWING BLADE LOOKING AREA 

2. Rotate the HPC through the gearbox to locate the blade loading slot or locking area to 

be inspected within the inspection view, refer to Figure 8a and 8b. 

3. Rotate the HPC counterclockwise through the gearbox to locate a position on the front 

rail of the 15th stage HPC disk approximately three (3) blades away from the blade 

loading slot or blade locking area to be inspected. 

4. Carefully insert the coil end of the PWA 105249 eddy current probe assembly into the AP7 borescope port alongside the borescope. 

5. Continue to insert the probe into the engine cavity until the coil tip contacts the front rail 

of the 15th stage HPC disk, refer to Figure 9. Verify the position of the coil tip against 

the front rail of the disk using the view provided by the borescope. 

`
NDIP-1014 REV. B Effective 06/07/2010

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EDDY CURRENT PROBE 

 FRONT RAIL 

FWD

POSITION EDDY CURRENT 

PROBE FOR INSPECTION 

IN THIS AREA 

Figure 9 Eddy Current Inspection on the Front Rail of the HPC 15th Stage Disk 

6. Inspect the blade loading slot or blade locking area on the front rail of the 15th stage 

HPC disk. 

a. Turn on the oscillographic recorder. 

b. Apply a slight radial inward pressure to the probe handle to maintain contact of the 

coil tip on the front rail. 

c. Starting at the area three (3) blades away from the blade loading slot or blade 

locking area, rotate the HPC clockwise through the gearbox towards the blade 

loading slot area to be inspected while monitoring the eddy current response. 

d. Continue the HPC rotation until the probe has inspected an area of the front rail that 

encompasses eight (8) blades. 

e. Rotate the HPC counterclockwise through the gearbox back towards the blade 

loading slot area until the area encompassing a total of eight (8) blades has been 

re-inspected to verify the eddy current response. 

e. Turn off the oscillographic recorder. 

7. The recorder trace will exhibit a baseline eddy current response with an amplitude of less 

than 0.5 inch (12.7 mm) as the probe traverses along the inspection area, Figure 10. 
NDIP-1014 REV. B Effective 06/07/2010 

18

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FIGURE 10 

A TYPICAL BASELINE RESPONSE 

a. The recorder trace should be approximately 2 inches (50 mm) long for each 

traverse, refer to Figure 10. 

b. The baseline response should have a wavy appearance with an amplitude 

less than 0.5 inch (12.7 mm) due to a minimal response from the blade 

platforms. 

8. An eddy current indication is a rapid upscale and return pen movement, A 

typical eddy current inspection is shown in Figure 11. 
NDIP-1014 REV. B Effective 06/07/2010

19

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FIGURE 11 

A TYPICAL EDDY CURRENT INDICATION 

a. If an indication is observed, evaluate the eddy current response from the two scans. 

b. If necessary, re-traverse the area to repeat and verify the amplitude of the eddy 

current indication. 

9. Remove the eddy current probe from the AP-7 borescope access port. 
NDIP-1014 REV. B Effective 06/07/2010 

20

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F. ENGINE RE-ASSEMBLY 

1. Carefully remove the borescope from the AP-7 borescope access port. 

2. Carefully disconnect and remove all test equipment and fixturing from the engine and 

store in the container provided to prevent damage. 

3. Remove the engine rotating device and replace the gearbox crank pad cover. 

4. Replace the AP-7 borescope access port sleeve and plug. 

5. Close the cowl panels and open the thrust reverser.

G. REPORTING CRITERIA 

1. Any 15th stage HPC disk front rail which exhibits an eddy current indication with an 

amplitude equal to or greater than 1.0 inch (25.4 mm) must be removed from service. 

H. REPORTING 

1. Report inspection results to local Pratt & Whitney Field Representative detailing the 

following information. 

a. Aircraft serial number and engine position. 

b. Engine model, engine serial number, and engine total time and total cycles. 

c. 15th stage HPC disk part number, total part time and total part cycles since new 

and last inspection, if available. 

d. Inspection method and results.