# General Electric Service Bulletin 72-0528: Revision R01

- Rights: © General Electric Company. Filed by the FAA in regulations.gov docket FAA-2013-0186; AD 2013-17-07 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [General Electric Service Bulletin 72-0528](https://openairdocs.org/service-documents/ge/sb-72-0528.md)
- Title as filed: GE 90-100 Service Bulletin - 72-0528-R01
- Pages: 20
- PDF: https://openairdocs.org/files/sha256/12/fc/12fced596bf02729796aefac60f7835d14f92b9f612758fbd24aaf048b335d56
- Page: https://openairdocs.org/service-documents/ge/sb-72-0528/file/12fced596bf0

## Text

This text is OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
GE PROPRIETARY INFORMATION
The information contained in this document is GE proprietary information
and is disclosed in confidence. It is the property of GE and shall not
be used, disclosed to others or reproduced without the express written
consent of GE, including, but without limitation, it is not to be used
in the creation, manufacture, development, or derivation of any repairs,
modifications, spare parts, designs, or configuration changes or to
obtain FAA or any other government or regulatory approval to do so. If
consent is given for reproduction in whole or in part, this notice and
the notice set forth on each page of this document shall appear in any
such reproduction in whole or in part.
This technical data is considered EAR controlled pursuant to 15 CFR
Parts 730-774 respectively. Transfer of this data by any means to a Non-
US Person, whether in the United States or abroad, without the proper
U.S. Government authorization (e.g., License, exemption, NIR, etc.), is
strictly prohibited.
Copyright (2013) General Electric Company, U.S.A.
TRANSMITTAL INFORMATION
REVISION 1 TO SERVICE BULLETIN 72-0528
Revision 1 is issued to update paragraph 3., ACCOMPLISHMENT
INSTRUCTIONS.
The original was issued November 15, 2012. Revision bars in the left
margin identify changes.
1. PLANNING INFORMATION
A. Effectivity
* * * GE90-110B1 and -115B
This Service Bulletin is applicable to these GE90-100 engines:
•GE90-100 engines, serial numbers 906-682 through 906-690, 906-
701 through 906-704, 906-706 through 906-709, 906-712, 906-713,
906-716 and up.
These serial numbers are the best available data.
This Service Bulletin is also applicable to all GE90-100 engines
that had the stage 1 high pressure turbine (HPT) stator shrouds
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical  Page
Printed:  data is considered ITAR and/or EAR controlled; transfer of this
1 of 20
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 2 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
P/N 1847M52P16 installed during a shop visit (post-GE90-100 S/B
72-0363).
B. Description
This Service Bulletin provides on-wing borescope inspection (BSI)
procedures for the stage 1 HPT stator shrouds P/N 1847M52P16.
C. Compliance
Category 2
GE recommends this inspection be performed at a 2,000 cycles
since new (CSN)  threshold for production engines and 2,000 cycles
since installation (CSI) on engines that had the stage 1 HPT
stator shrouds P/N 1847M52P16 installed during a shop visit.
GE also recommends this inspection be repeated at 250 cycle
intervals thereafter.
NOTE: For engines that have accumulated more than 2,000 cycles on the stage 1 HPT
stator shroud P/N 1847M52P16 at the time of initial publication of this
Service Bulletin, GE recommends the affected engine be inspected within two
months of the initial publication date of this Service Bulletin.
NOTE: For engines that have less than 2,000 cycles on the stage 1 HPT stator shroud
P/N 1847M52P16 at the time of initial publication of this Service Bulletin, GE
recommends the affected engine be inspected within two months of reaching
2,000 cycles on the stage 1 HPT stator shrouds.
NOTE: Compliance with GE90-100 S/B 72-0348 is a terminating action for this Service
Bulletin.
NOTE: This Service Bulletin does not supersede GE90-100 S/B 72-0401, and has a
different effectivity.
NOTE: This Service Bulletin can be accomplished on wing or in shop.
This Service Bulletin is offered to improve the reliability or
performance of your GE product, or to help prevent the occurrence
of the event or condition described in this Service Bulletin. If
the operator elects not to participate in the bulletin, that
decision will be taken into consideration by GE in evaluating
future product performance issues that may arise in the
operator's fleet.
D. Concurrent Requirements
None.
E. Reason
(1) Objective:
To improve reliability and reduce significant events.
(2) Condition:
The stage 1 HPT stator shrouds show an accelerated
deterioration that can result in an unserviceable condition.
(3) Cause :
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical  Page
Printed:  data is considered ITAR and/or EAR controlled; transfer of this
2 of 20
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 3 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
The cause for the accelerated distress is currently under
investigation.
(4) Inspection:
Inspect the stage 1 HPT stator shrouds for corrosion/oxidation
and missing material/holes.
(5) Substantiation:
Substantiation is by fleet experience and analysis.
F. Approval
This Service Bulletin contains no modification information that
revises the approved configuration and therefore does not require
FAA approval.
G. Manpower
After you get access to the borescope port of the stage 1 HPT
stator shrouds, you will need approximately 4 man-hours to do the
inspection portion of this Service Bulletin.
H. Weight and Balance
Weight and balance are not changed.
I. References (Use the latest version of these documents)
GE90-100 Boeing 777 Aircraft Maintenance Manual (AMM)
GEK 110005, GE90-100 Illustrated Parts Catalog (IPC)
GE90-100 S/B 72-0348, ENGINE - HPT Stage 2 Nozzle Assembly (72-
52-00) - Stage 1 HPT Stator Shroud and Stage 1 HPT Stator Shroud
Hanger - New and Rework
GE90-100 S/B 72-0363, ENGINE - General (72-00-00) - Spare Parts
Release for GE90-100  Engines
GE90-100 S/B 72-0401, ENGINE - HPT Stage 2 Nozzle (72-52-00) -
On-Wing Borescope Inspection of Stage 1 HPT Stator Shroud
J. Publications Affected
GE90-100 Boeing 777 Aircraft Maintenance Manual (AMM)
K. Interchangeability
Not applicable.
L. Software Accomplishment Summary
Not applicable.
2. MATERIAL INFORMATION
A. Material - Price and Availability
(1) Parts necessary to do this Service Bulletin:
None.
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical
Page
Printed:  data is considered ITAR and/or EAR controlled; transfer of this  3 of 20
Jun 24,  2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 4 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013 Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
(2) Other Spare Parts:
None .
(3) Consumables:
None.
B. Industry Support Information
Contact your Customer Support Manager (CSM).
C. Confiquration Chart
Not applicable.
D. Parts Disposition
None.
E. Tooling - Price and Availability
Tool Number  Description
Torque Wrench capable of up to 220 1b in. (25 N m)
Flexible Borescope (flexscope) 6 mm or 8 mm
diameter minimum of 3.5 meters in length
(recommended equipment)
NOTE:A flexscope shorter than 3.5 meters cannot be used to accomplish this
inspection.
3. ACCOMPLISHMENT INSTRUCTIONS
A. Stage 1 HPT Stator Shroud BSI with a 3.5-Meter or Longer
Flexscope
NOTE: Video BSI or photos are strongly recommended when this inspection is done.
NOTE: Stage 1 HPT stator shroud damage has been seen at all clock positions.
Damage occurs more at mid chord and aft on stage 1 HPT stator shroud
surface. Inspection of the entire stage 1 HPT stator shroud surface is
required. You must look between the blades and under the blade tips to
make sure that no indications are missed.
WARNING: USE THERMAL GLOVES WHEN YOU MOVE OR TOUCH HOT OR COLD PARTS. HOT OR COLD
PARTS CAN CAUSE INJURY.
CAUTION: MAKE SURE THE TEMPERATURE OF THE ENGINE AND THE ADJACENT AREAS NEAR THE
BSI PORTS ARE LESS THAN 150 F (66 C) DEGREES. DO NOT DO A BSI IF THE
ADJACENT AREAS ARE TOO HOT TO TOUCH. DO THE BSI WHEN THE ENGINE
TEMPERATURE IS LESS THAN 150 F (66 C) DEGREES. THIS WILL PREVENT DAMAGE
TO THE BORESCOPE EQUIPMENT.
(1) Do a 360-degree BSI of the stage 1 HPT stator shroud (1,
Figure 1) leading edge (LE) and mid chord. Refer to the GE90-
100 Boeing 777 AMM, TASK 72-00-00-290-805-H01, SUBTASK 72-00-
00-290-007-H01, and do as follows:
NOTE: A flexscope less than 3.5 meters in length cannot be used to do the BSI of
the stage 1 HPT stator shrouds.
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  4 of 20
prohibited.

### Page 5 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
(a) Remove the borescope plug at the "Q" location.
(b) Insert a flexscope into the borescope port of the combustor
diffuser nozzle (CDN) and pass it into the flow path.
(c) Follow the direction of the stage 1 HPT nozzle and continue
to insert the flexscope over the top of the engine.
Continue to feed the flexscope into the flow path until you
can see the flexscope insertion point (flexscope entering
through the borescope port).
NOTE: It is very important that you can see the borescope entry point to make
sure that a full 360 degrees flexscope travel has been accomplished for
the inspection.
(d) Carefully remove the flexscope. Make sure to examine the
stage 1 HPT stator shrouds as you remove the flexscope.
Inspect the mid chord of the stage 1 HPT stator shrouds
(area of the stage 1 HPT stator shrouds between the blades)
and the LE of the stage 1 HPT stator shrouds.
(e) While you examine the stage 1 HPT stator shrouds, evaluate
each stage 1 HPT stator shroud as specified in paragraph
3.B., Inspection Results Evaluation, and complete the
Inspection Findings Report Form as specified in paragraph
3.C., Inspection Findings Reporting, and Figure 3.
(f) When you complete the inspection, install the borescope
plug. Refer to the GE90-100 Boeing 777 AMM, SUBTASK 72-00-
00-410-011-H01.
(2) Do a 360-degree BSI of the stage 1 HPT stator shroud (1,
Figure 1) trailing edge (TE) and mid chord as follows:
NOTE:A flexscope less than 3.5 meters in length cannot be used to do the BSI of
the stage 1 HPT stator shrouds.
(a) Remove the borescope plug at the "R" location.
(b) Insert a flexscope into the borescope port of the HPT case
and pass it into the flow path.
(c) Follow the direction of the stage 2 HPT nozzle and continue
to insert the ilexscope under the bottom oi the engine.
Continue to feed the flexscope into the flow path until you
can see the flexscope insertion point (flexscope entering
through the borescope port).
NOTE: It is very important that you can see the borescope entry point to make
sure that a full 360 degrees flexscope travel has been accomplished for
the inspection.
(d) Carefully remove the flexscope. Make sure to examine the
stage 1 HPT stator shrouds as you remove the flexscope.
Inspect the mid chord of the stage 1 HPT stator shrouds
(area of the stage 1 HPT stator shrouds between the blades)
and the TE of the stage 1 HPT stator shrouds.
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical
Page
Printed:  data is considered ITAR and/or EAR controlled; transfer of this  5 of 20
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 6 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
(e) While you examine the stage 1 HPT stator shrouds, evaluate
each stage 1 HPT stator shroud as specified in paragraph
3.B., Inspection Results Evaluation, and complete the
Inspection Findings Report Form as specified in paragraph
3.C., Inspection Findings Reporting, and Figure 4.
(f) When you complete the inspection, install the borescope
plug. Refer to the GE90-100 Boeing 777 AMM, SUBTASK 72-00-
00-410-014-H01.
B. Inspection Results Evaluation
(1) Use the shroud serviceability limits published in the GE90-100
Boeing 777 AMM, TASK 72-00-00-290-805-H01, SUBTASK 72-00-00-
290-007-H01, except for the following:
NOTE: Refer to Figure 2 for examples of the stage 1 HPT stator shrouds thermal
distress.
(a) Holes within 0.35 inch (8.9 mm) of the LE are serviceable
on a reduced inspection interval of every 50 cycles.
(b) Holes beyond 0.35 inch (8.9 mm) of the LE less than 0.15
inch (3.8 mm) in diameter [maximum area of 0.018 sq in.
(0.12 sq cm)] are serviceable on a reduced inspection
interval of every 25 cycles if the LE of the shroud is
present forward of the hole.
NOTE: If you can see the stage 1 hanger internal baffle, the damage is more
than 0.35 inch (8.9 mm) from the LE and must be evaluated in accordance
with the serviceability requirements listed above in this Service
Bulletin.
(c) Holes beyond 0.35 inch (8.9 mm) of the LE between 0.15 inch
(3.8 mm) in diameter [maximum area of 0.018 sq in. (0.12 sq
cm)] and 0.25 inch (6.4 mm) in diameter [maximum area of
0.049 sq in. (0.32 sq cm)] are serviceable on a reduced
inspection interval of every 10 cycles if the LE of the
shroud is present forward of the hole.
NOTE: If you can see the stage 1 hanger internal baffle, the damage is more
than 0.35 inch (8.9 mm) from the LE and must be evaluated in accordance
with the serviceability requirements listed above in this Service
Bulletin.
(d) Lifting of the shroud split line, LE or TE is acceptable if
the area of the lifting material meets the requirements in
the GE90-100 Boeing 777 AMM, SUBTASK 72-00-00-290-007-H01
for missing material.
(e) Black oxide/corrosion build up around the shroud cooling
holes on shroud flow path surface is acceptable for repeat
inspection interval of every 250 cycles.
(f) Black oxide/corrosion build up on shroud surface that
blocks cooling holes is acceptable for repeat inspection
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical  Page
Printed:  data is considered ITAR and/or EAR controlled; transfer of this
6 of 20
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 7 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
interval of every 100 cycles.
C. Inspection Findings Reporting
(1) Report the inspection findings to GE Group Field Service/PSE
Representative. Fill out the Inspection Findings Report Form.
Refer to Figure 3 and Figure 4.
(2) Video borescope/photograph the inspection of the stage 1 HPT
stator shrouds. Retain the inspection records for one year (12
months) .
(3) Send the completed Inspection Findings Report Form and
pictures to: kyle.blomgren@ge.com
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical  Page
Printed:  Jun 24, 2013  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  7 of 20

### Page 8 (OCR)

88) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
A-A
1 (REF)
D
LEGEND:
1. STAGE 1 HPT STATOR SHROUD (QTY -40)  1368214-00
Location of the Stage 1 HPT Stator Shroud
Figure 1 (Sheet 1)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical
Printed:  Jun 24, 2013  ' 2013 prohibited ion us Person, without  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  8 of 20  Page

### Page 9 (OCR)

06] GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
TE STAGE 1 HPT  • STAGE 1 HPT STATOR
NOZZLE  SHROUD HANGER
LE STAGE 2 HPT
NOZZLE
1 (REF)
STAGE 1 HPT ROTOR
BLADE TIP TE
1368219-00
Location of the Stage 1 HPT Stator Shroud
Figure 1 (Sheet 2)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  or reproduced without the express written consent of GE. Technical
Printed:  data is considered ITAR and/or EAR controlled; transfer of this  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  9 of 20
prohibited.

### Page 10 (OCR)

96) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
DISTANCE FROM SHROUD
LE TO FORWARD
SIDE OF SHROUD RAIL
0.200  LE  0.350
(5.08)  (8.89)
STAGE 1 SHROUD
APPROXIMATED
DIMENSIONS TO
COOLING HOLE ROWS
0.200  TE  LE
(5.08)
1. BLACK DOTS ARE THE AIR FLOW EXIT HOLES
OF THE STACE 1 HPT STATOR SHROUD.
2. DIMENSIONS FOR HOLE COOLING HOLE
LOCATIONS ARE FOR THE STAGE 1 HPT
STATOR SHROUD P/N 1847M52P16.
3. DIMENSIONS ARE IN INCHES WITH
MILLIMETERS IN PARENTHESES.
4. DIMENSIONS ARE APPROXIMATE AND TO
BE USED FOR REFERENCE ONLY.  1368220-00
Location of the Stage 1 HPT Stator Shroud
Figure 1 (Sheet 3)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  10 of 20
prohibited.

### Page 11 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
APPROXIMATE DISTANCE BETWEEN
COOLING HOLE ROWS 0.300 (7.62)
APPROXIMATE DISTANCE BETWEEN
COOLING HOLE ROWS 0.200 (5.08)
BLOCKED COOLING HOLES
SERVICEABLE ON A 100 CYCLE
RE-INSPECTION
LE HPT STAGE 1 ROTOR BLADE
NO BLOCKED COOLING HOLES  REFER TO
RE-INSPECTION  SERVICEABLE ON A 250 CYCLE  LE STAGE 1 HPT  TE STAGE 1 HPT NOZZLE  OUTER PLATFORM  NOTE 3
STATOR SHROUD
MATERIAL BUILD-UP IS A
SERVICEABLE CONDITION
1. THE DISTANCE FROM THE LE OF
THE STAGE 1 HPT STATOR SHROUD TO THE
LE OF THE STAGE 1 HPT ROTOR
BLADE IS APPROXIMATELY 0.35 (8.9).
THIS CAN BE USED AS A REFERENCE TO
DETERMINE THE APPROXIMATE LOCATION
OF ANY MISSING MATERIAL
2. INSPECT BETWEEN THE STAGE 1 HPT ROTOR
BLADE AIRFOILS.
3. OXIDE/CORROSION BUILD UP IS BLACK OR SILVER
MATERIAL ON SHROUD FLOW PATH
4. DIMENSIONS ARE IN INCHES WITH
MILLIMETERS IN PARENTHESES,  1368221-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 1)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Printed:  Date  Jun 24, 2013  data is considered ITAR and/or EAR controlled; transfer of this  or reproduced without the express written consent of GE. Technical  data to a Non-US Person, without USG authorization, is strictly  11 of 20  Page
prohibited.

### Page 12 (OCR)

86) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
HOLED STAGE 1 HPT STATOR
SHROUD FOUND AT SHOP VISIT
NOT A SERVICEABLE CONDITION
1. STAGE I HPT STATOR SHROUD DAMAGE
IS FOUND ANYWHERE AROUND THE
CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT.
3. INSPECTION OF THE ENTIRE STAGE 1 HPT
STATOR SHROUD FROM LE TO TE VUST BE
ACCOMPLISHED.  1368223-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 2)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
data is considered ITAR and/or EAR controlled; transfer of this  or reproduced without the express written consent of GE. Technical  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  12 of 20
prohibited.

### Page 13 (OCR)

| GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
HOLED STAGE 1 HPT STATOR
SHROUD FOUND AT SHOP VISIT
NOT A SERVICEABLE CONDITION
1. STAGE 1 HPT STATOR SHROUD DAMAGE
IS FOUND ANYWHERE AROUND THE
CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT
3. INSPECTION OF THE ENTIRE STAGE 1 HPT
STATOR SHROUD FROM LE TO TE VUST BE
ACCOMPLISHED.  1368321-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 3)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  _ Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  13 of 20
prohibited.

### Page 14 (OCR)

96) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
HOLED STAGE 1 HPT STATOR
SHROUD FOUND AT SHOP VISIT
NOT A SERVICEABLE CONDITION
1. STAGE 1 HPT STATOR SHROUD DAMAGE IS
FOUND ANYWHERE AROUND THE
CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT.
3. INSPECTION OF THE ENTIRE STAGE 1 HPT
STATOR SHROUD FROM LE TO TE MUST BE
ACCOMPLISHED  1368237-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 4)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  14 of 20
prohibited.

### Page 15 (OCR)

56) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
BSI OF HOLED STAGE 1
HPT STATOR SHROUD LE
NOT A SERVICEABLE CONDITION
TYPICAL BSI RESULTS SHOWING
MATERIAL BUILDUP ON STAGE 1
HPT STATOR SHROUD SURFACE LE
BLOCKED COOLING HOLES
SERVICEABLE ON A 100 CYCLE INSPECTION
NOTES:
1. STAGE 1 HPT STATOR SHROUD DAMAGE IS FOUND ANYWHERE
AROUND THE CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT,
3. INSPECTION OF THE ENTIRE STAGE 1 HPT STATOR SHROUD FROM
LE TO TE MUST BE ACCOMPLISHED.  1368322-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 5)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Printed:  Jun 24, 2013  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  15 of 20  Page
prohibited.

### Page 16 (OCR)

56) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
- 09 Now 12
15.57
THROUGH HOLE FOUND DURING BSI
FROM THE TE BORESCOPE
NOT A SERVICEABLE CONDITION
1. STAGE 1 HPT STATOR SHROUD DAMAGE IS FOUND ANYWHERE
AROUND THE CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT.
3. INSPECTION OF THE ENTIRE STAGE 1 HPT STATOR SHROUD FROM
LE TO TE MUST BE ACCOMPLISHED.  1368323-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 6)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Jun 24, 2013  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  16 of 20  Page
prohibited.

### Page 17 (OCR)

8) GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
07 Nov 12
05.33
DAMAGED COOUNG HOLE OF THE STAGE 1 HPT STATOR SHROUD.
NOT A THROUGH HOLE, SERVICEABLE CONDITION
1. STAGE 1 HPT STATOR SHROUD DAMAGE IS FOUND ANYWHERE
AROUND THE CIRCUMFERENCE OF THE ENGINE.
2. DAMAGE IS FOUND AT MID CHORD AND AFT
3. INSPECTION OF THE ENTIRE STAGE 1 HPT STATOR SHROUD FROM
LE TO TE MUST BE ACCOMPLISHED  1368324-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 7)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Jun 24, 2013  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  17 of 20  Page
prohibited.

### Page 18 (OCR)

96 GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
P9 det 12
04:45
LIFTING MATERIAL AT
STAGE 1 HPT STATOR
SHROUD TE AND SPLIT
LINE
SERVICEABLE IF IT MEETS
THE REQUIREMENTS FOR
MISSING MATERIAL PUBLISHED
IN THE GE90-100 BOEING AMM
1368222-00
Stage 1 HPT Stator Shrouds - Thermal Distress
Figure 2 (Sheet 8)
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Jun 24, 2013  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  data to a Non-US Person, without USG authorization, is strictly  18 of 20  Page
prohibited.

### Page 19 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
Clock
Borescapa Port  Stroud  poston
Lecation  Number  Angle  ALF  Description of Findings
Fort o Star Here  30G
12 o'clock  297
280
37  36 35 34  279
Por: Q  39  38  flexscope  5  379.  261  9 o'cloch
insertin  direction  30  252
29  243
28
ESN
Hours
Cycles
A/C Tail Nunaber
Engine Position
8 does
23
22
rural
10  and
direction
13 14  16 16 17
Aft Looking Forward(ALF)  24  20  90  3d clock
Please circle damaged shrouds on the schematic  26  01
above and record findings in the table to the right  21  72
28  63
Note: Identty ehroud No. 1 as the frat shroud to be inspected when the  29
flexscope is fully inserted ane the entrance point is visible (BSI Port Q).  30  45
Shroud No. 2 should be the next shroud to be inspected as the flexecope  31
be the last shrood inspected belore the flexscope is removed froin the  is pulled out counter clockwise (OCW) and so on. No. 40 groud ahould  32
insertion point.  1#
The final report sheuld als contain photographs of damaged areas  360  12 o'clock
labeled with location and damage dimensions.
e-mail completed inspection findings report for to:  35  361
kyle blomgren@ge.com  542
333
- 39  024
_40  _916
1368224-01
Inspection Findings Report Form - LE
Figure 3
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  Page
19 of 20
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly
prohibited.

### Page 20 (OCR)

GE90-100 Service Bulletin  No 72-0528 R01
Revised: 04/01/2013  Issued: 11/15/2012
SB 72-0528 R01 ENGINE - HPT Stage 2 Nozzle (72-52-00) - On-Wing Borescope
Inspection of Stage 1 HPT Stator Shrouds P/N 1847M52P16
12 o'clock  Borescope Port Shroud  position  Clock
Port R  Location  Number  Ample  ALF  Descripion of Findings
37  36 35 34  33  32 31  Port R Stort Here  39  37  342  333
38
39  35*
40  insertion  direction  30  35  36D  12 o'clock
29  3-1
28  33  18
32  27
ESN
31  20
Hours  45
Cycles
26  20  54
A/C Tail Number
20  63
Engine Position  24  27  72
23  26  01
22  25  90  3 c'dock:
24  99
canal
10  11 12  inspection  211kl  20  23  22  108  117
direction  21  126
13 14 15 16 17  20  135  144
Aft Looking Forward(ALF)  17  158  162
Please cirele damaged shrouds on the schematic  16  17*
above and record findings in the table to the right.  15  14  180  189  6 o'clock
13  198
1. entity shroud No. 35 as the first shroud to be inspocted when the
flexscope is fully inserted and the entrance point is visible (BSI Port F  12  207
Shroud No. 37 should be the next shroud to be inspected as the  11  216
flexscope is pulled out clockwise (CW) and so on. The No. 39 shroud  10  225
should be the last shroud inspected before the flexscope is ramoved  224
243
2. Shroud numbering from Port It Is same numbering sequence and
location as the Port O numbering for the LE inspection on Figure 3.  252
Frsl shroud to be inspected is at position number 38 and propresses  26"
270  8 0 0004
The final report should also contain photographa of damaged areas  279
Inbeled with location and damage dimensions
e-mar completed inspection findings report form to:  286
kyle.blomgreni@ge.com  297
306
40  _315
39  324
1368325-01
Inspection Findings Report Form - TE
Figure 4
GE PROPRIETARY INFORMATION - Not to be used, disclosed to others
Date  Printed:  or reproduced without the express written consent of GE. Technical  data is considered ITAR and/or EAR controlled; transfer of this  Page
Jun 24, 2013  data to a Non-US Person, without USG authorization, is strictly  20 of 20
prohibited.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.
