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Copyright (2017) General Electric Company, U.S.A.
TRANSMITTAL INFORMATION
REVISION 1 TO SERVICE BULLETIN 73-0059
Revision 1 is issued to update paragraphs 1., PLANNING INFORMATION, 2., MATERIAL INFORMATION, and 3., ACCOMPLISHMENT INSTRUCTIONS.
The original was issued July 13, 2017. Revision bars in the left margin identify changes.
1.PLANNING INFORMATION
A.Effectivity
* * * FOR GEnx-1B64, -1B64/P1, -1B64/P2, -1B67, -1B67/P1, -1B67/P2, -1B70, -1B70/75/P1, -1B70/75/P2, -1B70/P1, -1B70/P2, -1B70C/P1, -1B70C/P2, -1B74/75/P1, -1B74/75/P2, -1B76A/P2
This Service Bulletin is applicable to these GEnx-1B engines:
GEnx-1B engines, serial numbers 956-101 through 956-943.
These serial numbers are the best available data.
The machine bolts P/N AS3237-14 are affected by this Service Bulletin.
B.Description
 This Service Bulletin provides instructions to replace the machine bolts P/N AS3237-14 with longer machine bolts P/N J1494P15A or P/N AS3237-16 when the machine bolts of an individual fuel nozzle are removed from the engine in order to prevent future occurrences of loose or missing machine bolts, and any subsequent damage that can result to the under-cowl hardware.
C.Compliance
Category 5
GE recommends that you do this Service Bulletin as soon as the individual fuel nozzles are removed from the engine.
Impact C
This recommendation is to address a condition that may result in a Non-Event operational disruption, Unscheduled Engine Removals (UER), Out-Station-Removals or Aircraft on the Ground (AOG).
NOTE:
This Service Bulletin can be done 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 introduce new parts and reduce significant events.
(2)Condition:
Three engines have been found with loose or missing machine bolts from the fuel nozzle.
(3)Cause:
It has been determined that at 34 of the 88 fuel nozzle machine bolt locations, where additional support brackets are mounted to the combustor diffuser nozzle (CDN) case, the current machine bolt length is insufficient to supply an adequate margin of proper thread engagement with the secondary retention feature of the threaded inserts.
(4)Improvement:
The current fuel nozzle machine bolt is being replaced with a longer machine bolt at all 88 locations. This will ensure that, at the 34 locations identified with brackets, there will be sufficient thread engagement. This Service Bulletin addresses any situation prior to shop visit where a fuel nozzle is removed from the engine and the bolts are exposed.
(5)Substantiation:
Substantiation is by comparative analysis.
F.Approval
The data contained in this Service Bulletin has been reviewed by the FAA or authorized entity representing the FAA and the repair(s) and modification(s) herein comply with the applicable Aviation Regulations and are APPROVED for installation in the model(s) listed in this Service Bulletin.
G.Manpower
No additional man-hours are required to comply with this Service Bulletin.
H.Weight and Balance
Weight and balance are not changed.
I.References (Use the latest version of these documents)
GEnx-1B, Boeing 787 Aircraft Maintenance Manual (AMM)
 GEK 112851, GEnx-1B Engine Manual (EM)
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
NOTE:
The reference documents listed below are for the engine manufacturer's internal use only:
CID: 575919
BPP: 17-72-41-61968
J.Publications Affected
GEnx-1B, Boeing 787 Aircraft Maintenance Manual (AMM)
GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC)
K.Interchangeability
Qualified interchangeability.
Replace the old bolt with the new longer bolt. Do not replace the new longer bolt with the old bolt.
L.Software Accomplishment Summary
Not applicable.
2.MATERIAL INFORMATION
A.Material - Price and Availability
(1)Parts necessary to do this Service Bulletin:
 
Part Number
Qty/ Eng
Part Name
Unit ($) Price
Pkg Qty
Lead Time Days
 
J1494P15A
(AR)
Bolt, Machine
7.75
(1)
5
 
OR
 
AS3237-16*
(AR)
Bolt, Machine
NP
(-)
--
 
*Part not supplied by GE Engine Services Distribution L.L.C. Procure through local purchase.
NP = Not Provisioned
 NOTE:
Quantity is as required (AR) depending on the number of fuel nozzles removed.
NOTE:
Prices are provided for planning purposes and are subject to change.
(2)Other Spare Parts:
None.
(3)Consumables:
None.
B.Industry Support Information
None.
C.Configuration Chart
 
New Part Number
Qty/ Eng
Part Name
Old Part Number/ IPC Location
Qty/ Eng
Op Code
Chg/ Sprt Code
 
2376M54G01/
G02/G03/G04/
G05/G06/G07/
G08
(X)
Combustor Diffuser Assembly
2376M54G01/
G02/G03/G04/
G05/G06/G07/
G08
(X)
RM
-/-
 
.J1494P15A
05-010A, 73-11-30

06-010A, 73-11-30

(88)*
Bolt, Machine
(SIN 12520)
.AS3237-14
05-010, 73-11-30

06-010, 73-11-30

(88)*
RE
5/E
 
.AS3237-16
05-010B, 73-11-30

06-010B, 73-11-30

(ALT)
Bolt, Machine
(SIN 12520)
--
(-)
AD
5/-
 
*Actual quantity will depend on the number of fuel nozzles removed.
Operation Codes
AD=Add
RE=Replace
RM=Remains
Change Codes
5=Qualified interchangeability. Refer to paragraph 1.K., Interchangeability.
Support Codes
E=Old parts will be supplied, and can be used at other engine locations.
D.Parts Disposition
Use serviceable old parts at other engine locations.
E.Tooling - Price and Availability
None.
3.ACCOMPLISHMENT INSTRUCTIONS
A.General
 (1)Removal and installation instructions for the fuel nozzles (Figure 1) have not changed:
 (a)For on-wing replacement of the fuel nozzles (Figure 1), refer to the GEnx-1B, Boeing 787 AMM, 73-11-05, DMC-787-A-G73-11-05-00A-520A-A and DMC-787-A-G73-11-05-00A-720A-A.
 (b)For in-shop replacement of the fuel nozzles (Figure 1), refer to the GEnx-1B EM, 72-41-00, DISASSEMBLY 001, CONFIG 01, Subtask 72-41-00-040-024 or CONFIG 02, Subtask 72-41-00-040-044 and 72-40-00, ASSEMBLY 001, CONFIG 01, Subtask 72-40-00-440-085 or CONFIG 02, Subtask 72-40-00-440-180.
(2)Make sure to use the new machine bolt (1, Figure 1) in the position of the old machine bolt during the installation procedure.
Fuel Nozzle and Machine Bolt Location
Figure 1   (Sheet 1)
Fuel Nozzle and Machine Bolt Location
Figure 1   (Sheet 2)