Commercial 

Airplanes 747

Service Bulletin

Number: 747-56A2012

Original Issue: August 24, 2006

Revision 1: August 12, 2010

ATA System: 5611

SUBJECT: WINDOWS - Flight Compartment - Flight Compartment Windows - Inspection of Glass

No. 2 and No. 3 Windows for Cracks in the Fail-Safe Interlayer

Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15

CFR 730-774). An export license may be required before it is used for development, production or use by foreign

persons from specific countries. The controller of this data has the individual responsibility to abide by all export

laws.

ECCN: 9E991

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 2006 The Boeing Company

Unpublished Work - All Rights Reserved

Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable

subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.

This document includes proprietary information owned by The Boeing Company and/or one or more third parties.

Treatment of the document and the information it contains is governed by contract with Boeing. For more

information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.

Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,

BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the

Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in

connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

1 of 52

8.0
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

2 of 52

BOEING SERVICE BULLETIN 747-56A2012

BLANK PAGE
Table of Contents

Revision Transmittal Sheet ............................................ 5

Summary ...................................................... 7

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 30

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 31

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 32

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

FIGURE 1: NO. 2 AND NO. 3 WINDOW IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . 36

FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3

WINDOW DETAILED INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3

WINDOW DETAILED INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

3 of 52

BOEING SERVICE BULLETIN 747-56A2012
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

4 of 52

BOEING SERVICE BULLETIN 747-56A2012

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

Revision Transmittal Sheet Number: 747-56A2012

Original Issue: August 24, 2006

Revision 1: August 12, 2010

ATA System: 5611

SUBJECT: WINDOWS - Flight Compartment - Flight Compartment Windows - Inspection of Glass

No. 2 and No. 3 Windows for Cracks in the Fail-Safe Interlayer

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

Federal Aviation Administration (FAA) Airworthiness Directive FAA AD 2007-15-10 is related to this service

bulletin.

No more work is necessary on airplanes changed as given in the original issue of this service bulletin. Continue

to do repeat inspections as given in Revision 1 until the new dual structural glass pane windows are installed

as given in Paragraph 1.E., Compliance.

No airplanes were added to the service bulletin effectivity; however, airplanes line number 1418 and on were

removed.

REASON FOR REVISION

This revision is sent to remove airplanes line number 1418 and on from the service bulletin effectivity and give

terminating action for the requirements of continued inspection as given in this service bulletin. The inspections

as given in this service bulletin are necessary on airplanes prior to line number 1418, which had single structural

glass pane windows that can have cracks in the internal fail-safe interlayer. The inspections as given in this

service bulletin are not necessary on airplanes line number 1418 and on, which have the new dual structural

glass pane windows installed in production. The installation of the new dual structural glass pane windows as

given in Revision 1 of this service bulletin is terminating action for the requirements of continued inspection as

given in this service bulletin.

These sections were changed:

1. Summary (Background and Action); Paragraph 1.C., Reason; and Paragraph 1.D., Description, were

changed to clarify the difference between the single structural and dual structural glass pane windows.

Correct names of different parts of the window assembly were added. Also added production incorporation

information of the new dual structural glass pane window.

2. In Summary (Effectivity) and Paragraph 1.A., Effectivity, airplanes line number 1418 and on were removed.

3. In Summary (Compliance), added a reference to AD 2007-15-10.

4. In Paragraph 1.D., Description, a note in reference to sending inspection program and results was deleted.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

5 of 52
5. In Paragraph 1.E., Compliance, updated compliance tables to show conditions that affect the new dual

structural glass pane windows, which is terminating action to the requirements of the continued inspection.

Also added a reference to AD 2007-15-10.

6. In Paragraph 1.F., Approval, an Alternative Method of Compliance statement to the requirements of AD

2007-15-10 was added.

7. In Paragraph 1.G., Manpower, the words "single structural glass pane" were added to the No. 2 and No. 3

window inspection task.

8. In Paragraph 1.J.1., Existing Data, references were updated.

9. In Paragraph 1.K., Publications Affected, affected publications and damage tolerance evaluation statement

were added.

10. In Paragraph 1.L., Interchangeability and Intermixability of Parts, statement was updated.

11. In Paragraph 2.C.2., Parts and Materials Supplied by the Operator, part information was updated.

12. In Paragraph 3.A., General Information, 747 minor models were removed from the reference to Structural

Repair Manual, Chapter 51. Also added a note.

13. In Paragraph 3.B., Work Instructions, updated PART 1 and PART 2 instructions that affect the new dual

structural glass pane windows. Added PART 3 to give window replacement instructions.

14. In Figure 1, notes were updated and added new dual structural glass pane window part numbers in the

step table.

15. In Figure 2 and Figure 3, updated the step tables to add and clarify inspection requirements of the windows.

Information Notice 747-56A2012 IN 01 and 02 were addressed.

16. In Summary Figure, Figure 2, and Figure 3, illustrations were updated to show text changes on part

description.

Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location

of important changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

Original Issue: August 24, 2006

Revision 1: August 12, 2010

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

6 of 52

BOEING SERVICE BULLETIN 747-56A2012
Commercial 

Airplanes 747

Service Bulletin

Summary Number: 747-56A2012

Original Issue: August 24, 2006

Revision 1: August 12, 2010

ATA System: 5611

SUBJECT: WINDOWS - Flight Compartment - Flight Compartment Windows - Inspection of Glass

No. 2 and No. 3 Windows for Cracks in the Fail-Safe Interlayer

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Accomplishment of the inspection given in this service bulletin will make sure that no cracks are present in the

internal fail-safe interlayer of the No. 2 and No. 3 windows that use a single structural glass pane. Fail-safe

interlayer cracks can cause the affected windows to not be capable of carrying cabin pressurization loads if the

structural glass pane of the window becomes broken. This could result in loss of a window and rapid loss of

cabin pressure. Loss of a window can also cause crew communication difficulties or incapacitation of the crew.

The left No. 2 and No. 3 windows are the pilot's side windows. The right No. 2 and No. 3 windows are the

co-pilot's side windows.

Affected airplanes may have No. 2 and No. 3 windows that are made from either acrylic or glass. The detailed

inspections in this service bulletin are required only for glass windows that use a single structural glass pane to

carry pressure loads. Airplanes prior to line number 1418 had single structural glass pane window, which can

have cracks in the internal fail-safe interlayer. Windows that use dual structural glass panes or acrylic panes do

not require inspections. Airplanes line number 1418 and on have No. 2 and No. 3 windows that use dual structural

glass panes, which are installed in production. For airplanes prior to line number 1418, installation of the new

dual structural glass pane windows is terminating action for the requirements of continued inspection as given

in this service bulletin.

There are two different, but interchangeable, designs for the No. 2 and No. 3 windows that use a single structural

glass pane. The 65B27042-( ) and 65B27043-( ) windows consist of an outer glass pane and a structural inner

glass pane, with a vinyl interlayer between them. The vinyl interlayer alone acts as the structural fail-safe load

path if the structural inner glass pane becomes broken. The 65B27046-( ) and 65B27047-( ) windows consist

of an outer glass pane and a structural inner glass pane, separated by an outboard urethane interlayer, a vinyl

interlayer, and an inboard urethane interlayer. The vinyl and inboard urethane interlayers act as the structural

fail-safe load path if the structural inner glass pane becomes broken.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

7 of 52
One operator told Boeing that a glass No. 3 window with 36,131 flight-hours and 5,607 flight-cycles departed

an airplane in-flight. Loss of the window resulted in rapid loss of cabin pressure, and an emergency landing was

performed. Investigation revealed that a crack was present in the fail-safe interlayer of the 65B27043-2 single

structural glass pane No. 3 window, along the inner edge of the window's aluminum edge insert. When the

structural inner glass pane cracked due to an electrical arcing event not associated with the interlayer cracking,

the interlayer was not able to support the airplane's cabin pressurization load and the window departed the

airplane. The remaining single structural glass pane No. 3 window and both single structural glass pane No. 2

windows of this airplane were inspected, and all were found to have cracks in the fail-safe interlayer.

Subsequent to this report, inspections accomplished by Boeing and some operators have found many additional

instances of fail-safe interlayer cracks in 65B27042-( ) and 65B27043-( ) single structural glass pane No. 2 and

No. 3 windows. In addition, several instances of inboard fail-safe interlayer cracks were found in 65B27046-( )

and 65B27047-( ) glass No. 2 and No. 3 windows.

Interlayer cracks are primarily caused by thermal stress due to the different thermal expansion properties of the

vinyl, glass, and window edging material. Moisture ingression into the window can also contribute to interlayer

cracks.

Accomplishment of the inspection in this service bulletin will ensure the structural integrity of the No. 2 and No.

3 windows that use a single structural glass pane.

Boeing Service Related Problem (SRP) 747-SRP-56-0016 is related to this service bulletin.

ACTION (PRR 85901-85S)

Get internal access to the No. 2 and No. 3 windows on both the left and right sides of the airplane. Identify the

windows (by part number) to determine if they are single structural glass pane, dual structural glass pane, or

acrylic windows. No additional inspections are necessary on the following No. 2 and No. 3 windows, unless the

windows are replaced with the single structural glass pane windows:

– 65B07639-( ) or 65B07640-( ) acrylic windows

– 141U4821-( ), 141U4831-( ), 141U4822-( ), or 141U4832-( ) dual structural glass pane windows

Do a detailed inspection for cracks or damage, particularly in the internal interlayers for the following No. 2 and

No. 3 windows that use single structural glass panes: 65B27042-( ), 65B27043-( ), 65B27046-( ), and 65B27047-(

). If no cracks or damage are found, do the inspection again at the time as given in this service bulletin. If any

cracks or damage as given in this service bulletin are found, replace the affected window before any more flights.

Do the inspection of all four windows again at the times as given in this service bulletin.

NOTE: Color photographs of typical No. 2 and No. 3 window damage can be found in Fleet Team Digest

Articles 747 FTD 56-05001 and 747-400 FTD 56-05001. These articles can be accessed through the

MyBoeingFleet website, or you may obtain copies from your local Boeing Field Service office.

As an alternative replace the single structural glass pane windows with dual structural glass pane windows.

Installation of the dual structural glass pane windows is terminating action for the requirements of continued

inspections as given in Paragraph 1.E., Compliance. Installation of the dual structural glass pane windows is

necessary at the time as given in Paragraph 1.E., Compliance.

EFFECTIVITY

747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F,

747SP, and 747SR airplanes. See Service Bulletin Paragraph 1.A.1 for effectivity.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

8 of 52

BOEING SERVICE BULLETIN 747-56A2012
COMPLIANCE

See Service Bulletin Paragraph 1.E. for compliance information.

Federal Aviation Administration (FAA) Airworthiness Directive AD 2007-15-10 is related to this service bulletin.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the inspection or repair procedures given in this service bulletin.

MANPOWER

Task Total Task-Hours Elapsed Hours

Window Identification and Inspection 4.50 2.50

MATERIAL INFORMATION

Operator Supplied Parts.

Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

9 of 52

BOEING SERVICE BULLETIN 747-56A2012
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

10 of 52

BOEING SERVICE BULLETIN 747-56A2012
Commercial 

Airplanes 747

Service Bulletin

Number: 747-56A2012

Original Issue: August 24, 2006

Revision 1: August 12, 2010

ATA System: 5611

SUBJECT: WINDOWS - Flight Compartment - Flight Compartment Windows - Inspection of Glass

No. 2 and No. 3 Windows for Cracks in the Fail-Safe Interlayer

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

This service bulletin is for the airplanes shown below. An equivalent change is on subsequent

production airplanes. Refer to PRR 85901-85S for data about this change.

Refer to Service Bulletin Index Document D6-30300 Part 3 for Airplane Variable Number, Line

Number, and Serial Number data.

GROUP CONFIGURATION DESCRIPTION

1 - 747 airplanes line number 1 through 1417.

Airplane Models:

747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400,

747-400D, 747-400F, 747SP, 747SR

Variable Number Group

RA001 - RA034 1

RA101 - RA115 1

RA161 - RA164 1

RA201 - RA203 1

RA216 - RA217 1

RA245 - RA246 1

RA251 - RA266 1

RA301 - RA318 1

RA351 - RA360 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

11 of 52
Variable Number Group

RA369 - RA373 1

RA401 - RA418 1

RA501 - RA502 1

RA521 - RA528 1

RA532 - RA548 1

RA551 - RA552 1

RA559 - RA561 1

RA581 - RA582 1

RA585 1

RA601 - RA602 1

RA631 - RA635 1

RA651 - RA652 1

RA671 - RA677 1

RA701 - RA702 1

RA721 - RA731 1

RA741 - RA745 1

RA749 - RA750 1

RA761 - RA762 1

RA781 - RA784 1

RA901 - RA916 1

RB001 - RB016 1

RB041 - RB044 1

RB071 - RB075 1

RB101 - RB102 1

RB411 - RB413 1

RB421 1

RB601 - RB607 1

RB681 - RB697 1

RB711 1

RB721 - RB723 1

RB741 - RB748 1

RD001 - RD004 1

RD021 - RD022 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

12 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RD041 - RD059 1

RD071 - RD072 1

RD081 - RD083 1

RD091 - RD092 1

RD101 - RD104 1

RD121 - RD127 1

RD131 - RD144 1

RD166 - RD167 1

RD171 - RD172 1

RD181 - RD183 1

RD201 - RD204 1

RD221 - RD227 1

RD231 - RD235 1

RD241 - RD243 1

RD251 - RD262 1

RD271 - RD272 1

RD291 - RD292 1

RD301 - RD302 1

RD311 1

RD351 - RD358 1

RD361 - RD366 1

RD381 - RD383 1

RD411 - RD414 1

RD421 - RD426 1

RD431 - RD435 1

RD441 - RD442 1

RD451 - RD456 1

RD461 1

RD471 - RD475 1

RD513 - RD519 1

RD531 - RD533 1

RD551 1

RD561 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

13 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RD571 1

RD581 - RD583 1

RD591 - RD593 1

RD601 - RD607 1

RD621 - RD623 1

RD641 - RD649 1

RD651 - RD659 1

RD661 1

RD671 1

RD681 - RD682 1

RD691 - RD692 1

RD701 - RD702 1

RD721 - RD722 1

RD741 - RD742 1

RD751 - RD755 1

RD761 1

RD771 - RD775 1

RD781 - RD783 1

RD791 - RD792 1

RE001 1

RF001 - RF006 1

RG001 - RG009 1

RG091 1

RG095 1

RG101 - RG104 1

RG121 - RG126 1

RG141 - RG142 1

RG161 - RG164 1

RG171 - RG174 1

RG191 - RG193 1

RG211 - RG213 1

RG221 - RG222 1

RH101 - RH102 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

14 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RH111 - RH112 1

RH121 - RH122 1

RJ131 - RJ133 1

RJ151 - RJ152 1

RJ301 - RJ303 1

RJ321 - RJ322 1

RJ331 - RJ333 1

RL401 - RL403 1

RL411 - RL436 1

RL451 - RL456 1

RL461 - RL462 1

RL471 - RL479 1

RL481 1

RL491 - RL492 1

RL501 - RL502 1

RL511 - RL516 1

RL521 - RL522 1

RL531 - RL534 1

RL551 1

RL561 - RL568 1

RL571 1

RL576 - RL577 1

RL579 1

RL581 - RL586 1

RL651 - RL655 1

RL671 - RL675 1

RL681 - RL684 1

RL751 - RL752 1

RM001 - RM007 1

RM010 - RM013 1

RM021 - RM024 1

RM026 - RM030 1

RM036 - RM045 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

15 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RM051 - RM053 1

RM071 1

RM081 - RM084 1

RM091 1

RM096 - RM097 1

RM116 - RM117 1

RM126 - RM132 1

RM136 - RM147 1

RM156 - RM158 1

RM166 - RM177 1

RM191 - RM192 1

RM231 - RM233 1

RM241 - RM246 1

RM261 - RM264 1

RM316 - RM318 1

RM331 - RM333 1

RM341 1

RM351 - RM355 1

RM366 - RM367 1

RM401 - RM403 1

RM426 1

RM431 1

RM441 - RM443 1

RM445 1

RM801 - RM803 1

RM811 - RM813 1

RM851 - RM859 1

RM861 - RM863 1

RM871 - RM899 1

RM901 - RM906 1

RM911 1

RR001 - RR005 1

RR021 - RR025 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

16 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RR031 1

RR201 - RR206 1

RR221 - RR226 1

RR261 - RR267 1

RR301 - RR310 1

RR331 - RR332 1

RR336 1

RR341 - RR345 1

RR361 - RR362 1

RR421 - RR422 1

RR431 - RR432 1

RR441 - RR442 1

RR451 1

RR501 - RR504 1

RR521 - RR522 1

RR526 1

RR531 1

RR551 - RR556 1

RR561 1

RR566 1

RR701 1

RR721 - RR724 1

RR746 - RR748 1

RR851 - RR856 1

RR861 - RR862 1

RR951 - RR952 1

RS001 - RS002 1

RS201 1

RS211 - RS212 1

RS221 - RS222 1

RS231 - RS241 1

RS251 - RS259 1

RS263 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

17 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RS265 - RS268 1

RS271 - RS276 1

RS291 - RS292 1

RS301 - RS306 1

RS311 - RS320 1

RS331 - RS333 1

RS341 - RS342 1

RS699 1

RS701 - RS703 1

RS711 - RS713 1

RS721 - RS722 1

RS731 - RS732 1

RS741 - RS743 1

RS751 - RS752 1

RS761 - RS762 1

RS771 1

RS781 - RS782 1

RS786 1

RT001 - RT014 1

RT021 - RT022 1

RT031 - RT035 1

RT041 - RT047 1

RT061 1

RT071 - RT075 1

RT101 - RT103 1

RT121 1

RT131 - RT137 1

RT151 - RT152 1

RT161 - RT168 1

RT401 - RT412 1

RT431 - RT447 1

RT451 - RT469 1

RT471 - RT499 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

18 of 52

BOEING SERVICE BULLETIN 747-56A2012
Variable Number Group

RT501 - RT535 1

RT551 - RT568 1

RT571 - RT591 1

RT601 - RT657 1

RT671 - RT673 1

RT681 - RT682 1

RT691 - RT699 1

RT701 - RT704 1

RT711 - RT717 1

RT741 - RT757 1

RT776 - RT777 1

RT781 - RT784 1

RT801 - RT803 1

RT811 - RT814 1

RT831 - RT837 1

RT861 - RT864 1

RT876 - RT880 1

RT931 - RT932 1

RT945 - RT949 1

RT951 - RT955 1

RT966 - RT967 1

RU001 - RU006 1

RU016 - RU017 1

RU031 - RU032 1

RU051 - RU052 1

RU059 - RU062 1

RU081 - RU083 1

RU101 - RU102 1

RU121 - RU132 1

RU801 - RU809 1

RU831 - RU841 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

19 of 52

BOEING SERVICE BULLETIN 747-56A2012
2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of the inspection given in this service bulletin will make sure that no cracks are present

in the internal fail-safe interlayer of the No. 2 and No. 3 windows that use a single structural glass pane.

Fail-safe interlayer cracks can cause the affected windows to not be capable of carrying cabin

pressurization loads if the structural glass pane of the window becomes broken. This could result in

loss of a window and rapid loss of cabin pressure. Loss of a window can also cause crew communication

difficulties or incapacitation of the crew.

The left No. 2 and No. 3 windows are the pilot's side windows. The right No. 2 and No. 3 windows are

the co-pilot's side windows.

Affected airplanes may have No. 2 and No. 3 windows that are made from either acrylic or glass. The

detailed inspections in this service bulletin are required only for glass windows that use a single structural

glass pane to carry pressure loads. Airplanes prior to line number 1418 had single structural glass

pane window, which can have cracks in the internal fail-safe interlayer. Windows that use dual structural

glass panes or acrylic panes do not require inspections. Airplanes line number 1418 and on have No.

2 and No. 3 windows that use dual structural glass panes, which are installed in production. For airplanes

prior to line number 1418, installation of the new dual structural glass pane windows is terminating

action for the requirements of continued inspection as given in this service bulletin.

There are two different, but interchangeable, designs for the No. 2 and No. 3 windows that use a single

structural glass pane:

— The 65B27042-( ) and 65B27043-( ) windows consist of an outer glass pane and a structural inner

glass pane, with a vinyl interlayer between them. The vinyl interlayer alone acts as the structural

fail-safe load path if the structural inner glass pane becomes broken.

— The 65B27046-( ) and 65B27047-( ) windows consist of an outer glass pane and a structural inner

glass pane, separated by an outboard urethane interlayer, a vinyl interlayer, and an inboard

urethane interlayer. The vinyl and inboard urethane interlayers act as the structural fail-safe load

path if the structural inner glass pane becomes broken.

In No. 2 and No. 3 windows that use dual structural glass panes or acrylic panes, the second pane,

not vinyl interlayer, acts as the structural fail-safe element.

One operator told Boeing that a glass No. 3 window with 36,131 flight-hours and 5,607 flight-cycles

departed an airplane in-flight. Loss of the window resulted in rapid loss of cabin pressure, and an

emergency landing was performed. Investigation revealed that a crack was present in the fail-safe

interlayer of the 65B27043-2 single structural glass pane No. 3 window, along the inner edge of the

window's aluminum edge insert. When the structural inner glass pane cracked due to an electrical

arcing event not associated with the interlayer cracking, the interlayer was not able to support the

airplane's cabin pressurization load and the window departed the airplane. The remaining single

structural glass pane No. 3 window and both single structural glass pane No. 2 windows of this airplane

were inspected, and all were found to have cracks in the fail-safe interlayer.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

20 of 52

BOEING SERVICE BULLETIN 747-56A2012
Subsequent to this report, inspections accomplished by Boeing and some operators have found many

additional instances of fail-safe interlayer cracks in 65B27042-( ) and 65B27043-( ) single structural

glass pane No. 2 and No. 3 windows. In addition, several instances of inboard fail-safe interlayer cracks

were found in 65B27046-( ) and 65B27047-( ) single structural glass pane No. 2 and No. 3 windows.

Interlayer cracks are primarily caused by thermal stress due to the different thermal expansion properties

of the vinyl, glass, and window edging material. Moisture ingression into the window can also contribute

to interlayer cracks.

Accomplishment of the inspection in this service bulletin will ensure the structural integrity of the No.

2 and No. 3 windows that use a single structural glass pane.

Revision 1 is sent to remove airplanes line number 1418 and on from the service bulletin effectivity

and give terminating action for the requirements of continued inspection as given in this service bulletin.

The inspections as given in this service bulletin are necessary on airplanes prior to line number 1418,

which had single structural glass pane windows that can have cracks in the internal fail-safe interlayer.

The inspections as given in this service bulletin are not necessary on airplanes line number 1418 and

on, which have the new dual structural glass pane windows installed in production. The installation of

the new dual structural glass pane windows as given in Revision 1 of this service bulletin is terminating

action for the requirements of continued inspection as given in this service bulletin.

These sections were changed:

1. Summary (Background and Action); Paragraph 1.C., Reason; and Paragraph 1.D., Description,

were changed to clarify the difference between the single structural and dual structural glass pane

windows. Correct names of different parts of the window assembly were added. Also added

production incorporation information of the new dual structural glass pane window.

2. In Summary (Effectivity) and Paragraph 1.A., Effectivity, airplanes line number 1418 and on were

removed.

3. In Summary (Compliance), added a reference to AD 2007-15-10.

4. In Paragraph 1.D., Description, a note in reference to sending inspection program and results was

deleted.

5. In Paragraph 1.E., Compliance, updated compliance tables to show conditions that affect the new

dual structural glass pane windows, which is terminating action to the requirements of the continued

inspection. Also added a reference to AD 2007-15-10.

6. In Paragraph 1.F., Approval, an Alternative Method of Compliance statement to the requirements

of AD 2007-15-10 was added.

7. In Paragraph 1.G., Manpower, the words "single structural glass pane" were added to the No. 2

and No. 3 window inspection task.

8. In Paragraph 1.J.1., Existing Data, references were updated.

9. In Paragraph 1.K., Publications Affected, affected publications and damage tolerance evaluation

statement were added.

10. In Paragraph 1.L., Interchangeability and Intermixability of Parts, statement was updated.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

21 of 52

BOEING SERVICE BULLETIN 747-56A2012
11. In Paragraph 2.C.2., Parts and Materials Supplied by the Operator, part information was updated.

12. In Paragraph 3.A., General Information, 747 minor models were removed from the reference to

Structural Repair Manual, Chapter 51. Also added a note.

13. In Paragraph 3.B., Work Instructions, updated PART 1 and PART 2 instructions that affect the

new dual structural glass pane windows. Added PART 3 to give window replacement instructions.

14. In Figure 1, notes were updated and added new dual structural glass pane window part numbers

in the step table.

15. In Figure 2 and Figure 3, updated the step tables to add and clarify inspection requirements of the

windows. Information Notice 747-56A2012 IN 01 and 02 were addressed.

16. In Summary Figure, Figure 2, and Figure 3, illustrations were updated to show text changes on

part description.

Boeing Service Related Problem (SRP) 747-SRP-56-0016 is related to this service bulletin.

D. Description

Get internal access to the No. 2 and No. 3 windows on both the left and right sides of the airplane.

Identify the windows (by part number) to determine if they are single structural glass pane, dual structural

glass pane, or acrylic windows. No additional inspections are necessary on the following No. 2 and

No. 3 windows, unless the windows are replaced with the single structural glass pane windows:

– 65B07639-( ) or 65B07640-( ) acrylic windows

– 141U4821-( ), 141U4831-( ), 141U4822-( ), or 141U4832-( ) dual structural glass pane windows

Do a detailed inspection for cracks or damage, particularly in the internal interlayers for the following

No. 2 and No. 3 windows that use single structural glass panes: 65B27042-( ), 65B27043-( ), 65B27046-(

), and 65B27047-( ). If no cracks or damage are found, do the inspection again at the time as given in

this service bulletin. If any cracks or damage as given in this service bulletin are found, replace the

affected window before any more flights. Do the inspection of all four windows again at the times as

given in this service bulletin.

NOTE: Color photographs of typical No. 2 and No. 3 window damage can be found in Fleet Team

Digest Articles 747 FTD 56-05001 and 747-400 FTD 56-05001. These articles can be accessed

through the MyBoeingFleet website, or you may obtain copies from your local Boeing Field

Service office.

As an alternative replace the single structural glass pane windows with dual structural glass pane

windows. Installation of the dual structural glass pane windows is terminating action for the requirements

of continued inspections as given in Paragraph 1.E., Compliance. Installation of the dual structural

glass pane windows is necessary at the time as given in Paragraph 1.E., Compliance.

Revision 1 - No more work is necessary on airplanes changed as given in the original issue of this

service bulletin. Continue to do repeat inspections as given in Revision 1 until the new dual structural

glass pane windows are installed as given in Paragraph 1.E., Compliance.

The work in this service bulletin is done in the maintenance zone(s) given below.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

22 of 52

BOEING SERVICE BULLETIN 747-56A2012
Affected Maintenance Zones

Model Zone

747-100, 747-100B, 747-100B 221, 222

SUD, 747-200B, 747-200C,

747-200F, 747-300, 747-400,

747-400D, 747-400F, 747SP,

747SR

E. Compliance

Table 1: No. 2 and No. 3 Window Identification

Condition Action Compliance Time (Whichever Occurs First)

Within 2 years after

the original issue

date of this service

bulletin.

Within 5,500 flight-hours after

the window was installed or

1,000 flight-hours after the

original issue date of this service bulletin, whichever occurs

later. (b)

Do Window Identification as

given in PART 1 of Paragraph

3.B., Work Instructions. (a)

All airplanes

Do detailed inspections as Refer to Table 2 Refer to Table 2

shown in Table 2.

65B27042-( ) or

65B27043-( ) single

structural glass pane

windows found or installed

Do detailed inspections as Refer to Table 3 Refer to Table 3

shown in Table 3.

65B27046-( ) or

65B27047-( ) single

structural glass pane

windows found or installed

No further action required for - -

that window position. (c)

65B07639-( ) or

65B07640-( ) acrylic

windows found or installed

No further action required for - -

that window position. (c)

141U4821-( ),

141U4822-( ),

141U4831-( ), or

141U4832-( ) dual structural glass pane windows found or installed

(a) Instead of inspecting the windows for identification, a review of maintenance records is acceptable if the

part number of the window can be positively determined from that review.

(b) If the number of flight-hours since the window was installed is not known, you must assume that the

window is beyond the 5,500 flight-hour limit.

(c) If the window is later replaced, refer to the applicable condition in this table for subsequent inspection

requirements of the replacement window.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

23 of 52

BOEING SERVICE BULLETIN 747-56A2012
Table 2: Detailed Inspections for 65B27042-( ) and 65B27043-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

Within 2 years -

after the original issue date

of this service

bulletin.

Within 5,500 flight-hours

after the window was installed or 1,000 flight-hours

after the original issue date

of this service bulletin,

whichever occurs later. (a)

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27042-( ) or

65B27043-( ) Single Structural

Glass Pane No. 2

and No. 3 Windows.

AND

Within 6 years of the Revision 1 date of this -

service bulletin.

Replace the window with

141U4821-( ), 141U4822-

( ), 141U4831-( ), and/or

141U4832-( ) dual structural glass pane windows

as given in PART 3 of

Paragraph 3.B., Work Instructions.

No further action required - -

for that window position.

(c) (d)

141U4821-( ),

141U4822-( ),

141U4831-( ),

and/or 141U4832-

( ) dual structural

glass pane replacement windows installed.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

24 of 52

BOEING SERVICE BULLETIN 747-56A2012
Table 2: Detailed Inspections for 65B27042-( ) and 65B27043-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

3,000 flight-hours

or 3 years,

whichever occurs

first.

Within 3,000 flight-hours or 3 years of the

initial inspection, whichever occurs first.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

No window cracks

or damage found.

Replace the window as Before further flight. -

given in PART 3 of Paragraph 3.B., Work Instructions. (c)

Window cracks or

damage found.

3,000 flight-hours

or 3 years,

whichever occurs

first.

Within 5,500 flight-hours after the window

was installed.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27042-( )

and/or 65B27043-

( ) single structural glass pane

replacement windows that are

new or have zero

flight hours.

3,000 flight-hours

or 3 years,

whichever occurs

first.

Do a detailed inspection of Before installation.

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27042-( )

and/or 65B27043-

( ) single structural glass pane

replacement windows that are not

new or have unknown flight

hours.

7,500 flight-hours

or 5 years,

whichever occurs

first.

Within 22,000 flight-hours after the window

was installed.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27046-( )

and/or 65B27047-

( ) single structural glass pane

replacement windows that are

new or have zero

flight hours.

7,500 flight-hours

or 5 years,

whichever occurs

first.

Do a detailed inspection of Before installation.

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27046-( )

and/or 65B27047-

( ) single structural glass pane

replacement windows that are not

new or have unknown flight

hours.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

25 of 52

BOEING SERVICE BULLETIN 747-56A2012
Table 2: Detailed Inspections for 65B27042-( ) and 65B27043-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

(a) If the number of flight-hours since the window was installed is not known, you must assume that the

window is beyond the 5,500 flight-hour limit.

(b) The detailed inspection of single structural glass pane windows is only applicable within 6 years after the

Revision 1 date of this service bulletin.

(c) Installation of 141U4821-( ), 141U4822-( ), 141U4831-( ), and/or 141U4832-( ) dual structural glass pane

windows is terminating action for the continued inspections as given in this service bulletin and is necessary

within 6 years after the Revision 1 date of this service bulletin.

(d) If the window is later replaced, refer to the applicable condition in this table for subsequent inspection

requirements of the replacement window.

Table 3: Detailed Inspections for 65B27046-( ) and 65B27047-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

Within 3 years -

after the original issue date

of this service

bulletin.

Within 22,000 flight-hours

after the window was installed or 1,000 flighthours after the original issue date of this service

bulletin, whichever occurs

later. (a)

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27046-( ) or

65B27047-( ) Single Structural

Glass Pane No. 2

and No. 3 Windows.

AND

Within 6 years of the Revision 1 date of this -

service bulletin.

Replace the window with

141U4821-( ), 141U4822-

( ), 141U4831-( ), and/or

141U4832-( ) dual structural glass pane windows

as given in PART 3 of

Paragraph 3.B., Work Instructions.

No further action required - -

for that window position.

(c) (d)

141U4821-( ),

141U4822-( ),

141U4831-( ),

and/or 141U4832-

( ) dual structural

glass pane replacement windows installed.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

26 of 52

BOEING SERVICE BULLETIN 747-56A2012
Table 3: Detailed Inspections for 65B27046-( ) and 65B27047-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

7,500 flight-hours

or 5 years,

whichever occurs

first.

Within 7,500 flight-hours or 5 years of the

initial inspection, whichever occurs first.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

No window cracks

or damage found.

Replace the window as Before further flight. -

given in PART 3 of Paragraph 3.B., Work Instructions. (c)

Window cracks or

damage found.

3,000 flight-hours

or 3 years,

whichever occurs

first.

Within 5,500 flight-hours after the window

was installed.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27042-( )

and/or 65B27043-

( ) single structural glass pane

replacement windows that are

new or have zero

flight hours.

3,000 flight-hours

or 3 years,

whichever occurs

first.

Do a detailed inspection of Before installation.

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27042-( )

and/or 65B27043-

( ) single structural glass pane

replacement windows that are not

new or have unknown flight

hours.

7,500 flight-hours

or 5 years,

whichever occurs

first.

Within 22,000 flight-hours after the window

was installed.

Do a detailed inspection of

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27046-( )

and/or 65B27047-

( ) single structural glass pane

replacement windows that are

new or have zero

flight hours.

7,500 flight-hours

or 5 years,

whichever occurs

first.

Do a detailed inspection of Before installation.

the windows as given in

PART 2 of Paragraph 3.B.,

Work Instructions. (b) (c)

65B27046-( )

and/or 65B27047-

( ) single structural glass pane

replacement windows that are not

new or have unknown flight

hours.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

27 of 52

BOEING SERVICE BULLETIN 747-56A2012
Table 3: Detailed Inspections for 65B27046-( ) and 65B27047-( ) Single Structural Glass Pane No. 2 and

No. 3 Windows

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever Occurs

First)

Condition Action

(a) If the number of flight-hours since the window was installed is not known, you must assume that the

window is beyond the 22,000 flight-hour limit.

(b) The detailed inspection of single structural glass pane windows is only applicable within 6 years after

the Revision 1 date of this service bulletin.

(c) Installation of 141U4821-( ), 141U4822-( ), 141U4831-( ), and/or 141U4832-( ) dual structural glass pane

windows is terminating action for the continued inspections as given in this service bulletin and is necessary within 6 years after the Revision 1 date of this service bulletin.

(d) If the window is later replaced, refer to the applicable condition in this table for subsequent inspection

requirements of the replacement window.

Federal Aviation Administration (FAA) Airworthiness Directive AD 2007-15-10 is related to this service

bulletin.

F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified

in this service bulletin comply with the applicable regulations and are FAA approved, as well as European

Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved

airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on

the airplane in its original Boeing delivery configuration or as modified by other approved Boeing

changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval

before incorporating this service bulletin.

The Manager of the FAA Seattle Aircraft Certification office (ACO) approves the applicability under

paragraph 1.A., "Effectivity" of Service Bulletin 747-56A2012, Revision 1, as an AMOC to the applicability

required by paragraph (c) of AD 2007-15-10. In addition, the Manager of the FAA Seattle ACO approves

the inspections, investigative and corrective actions with the corresponding compliance times specified

in Tables 1 through 3, under paragraph 1.E., “Compliance," of Service Bulletin 747-56A2012, Revision

1, as an AMOC to the inspection, investigative and corrective actions with the corresponding compliance

times specified in Table 1 through 3, under paragraph 1.E., “Compliance," of Service Bulletin

747-56A2012, dated August 24, 2006, required by paragraphs (f) and (g) of AD 2007-15-10. When this

service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be

approved by the FAA in accordance with paragraph (h) of the AD. All provisions of AD 2007-15-10 that

are not specifically referenced in this paragraph remain fully applicable and must be complied with.

G. Manpower

The table below shows an estimate of the task-hours necessary to do this inspection for each airplane.

This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator

task-hour data if necessary. The estimate does not include lost time. These are some examples of lost

time:

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

28 of 52

BOEING SERVICE BULLETIN 747-56A2012
— Time to adjust to the workplace

— Time to schedule the work

— Time to examine the work

— Time to cure the materials

— Time to make the parts

— Time to find the tools.

Number of Task-Hours Elapsed Hours

Persons

Task

Open Access 1 0.25 0.25

Identify the No. 2 and No. 3 Windows, 2 3.50 1.75

Left and Right (Figure 1)

Inspect the Single Structural Glass 2 0.50 0.25

Pane No. 2 and No. 3 Windows, Left

and Right (Figure 2 or Figure 3)

Close Access 1 0.25 0.25

TOTAL FOR EACH AIRPLANE 4.50 2.50

NOTE: More time will be required for window replacement if damage is found.

H. Weight and Balance Changes

None.

I. Electrical Load Data

747-400: Not changed.

All other 747: Not applicable.

J. References

1. Existing Data:

a. Service Related Problem (SRP) 747-SRP-56-0016

b. Engineering Change Memo PRR 85901-85S

c. Federal Aviation Administration (FAA) Airworthiness Directive AD 2007-15-10

d. 747-100/200/300 Aircraft Maintenance Manual (AMM) 25-13-03, 25-15-02, 56-11-00, 56-11-02

e. 747-400 Aircraft Maintenance Manual (AMM) 25-13-03, 25-15-02, 56-11-00, 56-11-02

2. Data supplied with this Service Bulletin:

None.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

29 of 52

BOEING SERVICE BULLETIN 747-56A2012
3. Installation Drawings Used in the Preparation of this Service Bulletin:

Drawing Number Title

141U0001 Window Instl - Control Cab No. 2

141U0002 Window Instl - Control Cab No. 3

These drawings were used to prepare this service bulletin. These drawings are not necessary to

make the specified changes, and are not supplied with this service bulletin. These drawings may

not be applicable to all airplane configurations or operators.

K. Publications Affected

1. Publications:

Publication Chapter-Section

747-100/200/300 Illustrated Parts Catalog 56-11

747-400 Illustrated Parts Catalog 56-11

747-400LCF Illustrated Parts Catalog 56-11

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.

L. Interchangeability and Intermixability of Parts

Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability

information.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

30 of 52

BOEING SERVICE BULLETIN 747-56A2012
2. MATERIAL INFORMATION

A. Material - Price and Availability

The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary For Each

Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin

does not show the Boeing price and supply data.

B. Industry Support Information

Boeing warranty remedies are not available for the inspection or repair procedures given in this service

bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts:

None.

2. Parts and Materials Supplied by the Operator:

Existing Part Number Notes

(b) (c)

Part Number QTY Name

(a)

65B27042-1 or 65B27046- -

1

Glass No. 2 Window Assembly - Left

Side (Manufactured by GKN)

141U4821-11 1

65B27042-1 or 65B27046- -

1

Glass No. 2 Window Assembly - Left

Side (Manufactured by PPG)

141U4822-11 1

65B27042-2 or 65B27046- -

2

Glass No. 2 Window Assembly -

Right Side (Manufactured by GKN)

141U4821-12 1

65B27042-2 or 65B27046- -

2

Glass No. 2 Window Assembly -

Right Side (Manufactured by PPG)

141U4822-12 1

65B27043-1 or 65B27047- -

1

Glass No. 3 Window Assembly - Left

Side (Manufactured by GKN)

141U4831-1 1

65B27043-1 or 65B27047- -

1

Glass No. 3 Window Assembly - Left

Side (Manufactured by PPG)

141U4832-11 1

65B27043-2 or 65B27047- -

2

Glass No. 3 Window Assembly -

Right Side (Manufactured by GKN)

141U4831-2 1

65B27043-2 or 65B27047- -

2

Glass No. 3 Window Assembly -

Right Side (Manufactured by PPG)

141U4832-12 1

(a) This new part is used in production. The installation of the new part is necessary at the time as given

in Paragraph 1.E., Compliance.

(b) You can not use the existing part to replace the new part.

(c) You can continue to use the existing part until the time as given in Paragraph 1.E., Compliance. If you

use the existing part, repeat inspections are necessary at the times as given Paragraph 1.E., Compliance.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

31 of 52

BOEING SERVICE BULLETIN 747-56A2012
3. Parts Modified and Reidentified:

None.

4. Parts Removed and Not Replaced:

None.

D. Parts Necessary to Change Spares

None.

E. Special Tooling - Price and Availability

None.

F. Special Tooling Necessary to do this Service Bulletin

No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance

and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine

operator tool supply to make sure all necessary tools are available.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

32 of 52

BOEING SERVICE BULLETIN 747-56A2012
3. ACCOMPLISHMENT INSTRUCTIONS

A. GENERAL INFORMATION

CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL

PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,

METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE

DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR

OTHER ELECTRICAL DAMAGE.

NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for

definition of the acronyms.

2. Obey all of the warnings and cautions given in the specified manual sections.

3. Unless shown differently, these dimensions and tolerances are used:

— Linear dimensions are in inches

— Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus

or minus 0.03 inch.

— Angular tolerance is plus or minus 2 degrees

— Torque limits to tighten nuts and bolts are given in 747 Structural Repair Manual,

Chapter 51.

4. A Detailed Inspection is defined as: An intensive examination of a specific item,

installation, or assembly to detect damage, failure, or irregularity. Available lighting

is normally supplemented with a direct source of good lighting at an intensity deemed

appropriate. Inspection aids such as mirrors magnifying lenses, etc. may be

necessary. Surface cleaning and elaborate procedures may be required.

5. If the inspection is to be done in bright daylight conditions, Boeing recommends use

of a high power LED flashlight to find fail-safe interlayer cracks.

6. These work instructions refer to procedures included on other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative

procedure, the accepted alternative procedure can be used. When the words "as

given in" are included in the instruction, the procedure in the Boeing document must

be used.

7. To avoid unscheduled removal of the airplane from service for window replacement,

Boeing recommends that operators have replacement window assemblies available

before window inspections begin.

8. This service bulletin contains instructions to remove and keep parts for installation.

However, before installation of any removed and kept part, the part must be in a

serviceable condition. Replacement of the removed and kept part with a new or

serviceable part of the same part number/specification is an acceptable alternative

unless otherwise stated in the service bulletin instructions.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

33 of 52

BOEING SERVICE BULLETIN 747-56A2012
B. WORK INSTRUCTIONS

PART 1 - WINDOW IDENTIFICATION

1. Get internal access to the flight deck windows and identify the No. 2 and No. 3 windows as given

in Figure 1.

2. If any of the following windows are found or installed, put the airplane back to a serviceable

condition:

– 65B07639-( ) or 65B07640-( ) acrylic windows

– 141U4821-( ), 141U4822-( ), 141U4831-( ), or 141U4832-( ) dual structural glass pane windows

No additional inspections are required on these windows.

3. If any glass 65B27042-( ), 65B27043-( ), 65B27046-( ), or 65B27047-( ) windows are found or

installed, put the airplane back to a serviceable condition.

PART 2 - WINDOW INSPECTION

1. Get internal access and prepare to inspect the No. 2 and No. 3 flight deck windows. Refer to

747-100/200/300 AMM 56-11-00 or 747-400 AMM 56-11-00 as an accepted procedure.

NOTE: If internal inspections are not adequate to determine the condition of the windows, also

do external inspections.

2. Do a detailed inspection of 65B27042-( ) and 65B27043-( ) single structural glass pane No. 2 and

No. 3 windows (left and right sides) as given in Figure 2.

3. Do a detailed inspection of 65B27046-( ) and 65B27047-( ) single structural glass pane No. 2 and

No. 3 windows (left and right sides) as given in Figure 3.

4. If any of the following cracks or damage are found, replace the affected window as given in PART

3:

a. The window has cracks in any fail-safe interlayer.

b. The window has cracks in a glass pane.

c. The window has chips in a structural glass pane.

d. The window shows any indications of arcing.

Arcing usually occurs near the window bus bars. Heat damage caused by arcing can be

identified by brown or black burn marks in the internal interlayer.

e. The window has any non-clear damage. Non-clear damage may indicate a degradation of

the structural capability of the window and may hinder inspection for other damage such as

fail-safe interlayer cracks or electrical arcing.

5. If no cracks or damage are found, put the airplane back to a serviceable condition. Do the

inspections as given in PART 2 again at the times as given in Paragraph 1.E., Compliance.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

34 of 52

BOEING SERVICE BULLETIN 747-56A2012
NOTE: As an alternative to repeat inspections, replace the single structural glass pane windows

with the dual structural glass pane windows as given in PART 3. Installation of the dual

structural glass pane windows is terminating action for the requirements of continued

inspection as given in this service bulletin and necessary at the time as given in Paragraph

1.E., Compliance.

PART 3 - WINDOW REPLACEMENT

1. Option 1:

a. Replace single structural glass pane No. 2 and/or No. 3 windows with 65B27042-( ), 65B27043-(

), 65B27046-( ) and/or 65B27047-( ) single structural glass pane No. 2. and/or No. 3 windows

as applicable. Refer to 747-100/200/300 AMM 56-11-02 or 747-400 AMM 56-11-02 as an

accepted procedure for the window replacement.

NOTE: 65B27042-( ) and 65B27046-( ) single structural glass pane No. 2. windows are

interchangeable.

65B27043-( ) and 65B27047-( ) single structural glass pane No. 3. windows are

interchangeable.

b. Do the inspections given in PART 2 again at the times as given in Paragraph 1.E., Compliance.

2. Option 2:

a. Replace 65B27042-( ) and/or 65B27046-( ) single structural glass pane No. 2 windows with

141U4821-( ) and/or 141U4822-( ) dual structural glass pane No. 2 windows. Refer to

747-100/200/300 AMM 56-11-02 or 747-400 AMM 56-11-02 as an accepted procedure for

the window replacement.

b. Replace 65B27043-( ) and/or 65B27047-( ) single structural glass pane No. 3 windows with

141U4831-( ) and/or 141U4832-( ) dual structural glass pane No. 3 windows. Refer to

747-100/200/300 AMM 56-11-02 or 747-400 AMM 56-11-02 as an accepted procedure for

the window replacement.

c. No more inspections are necessary as given in this service bulletin for the dual structural glass

pane No. 2 and No. 3 windows.

3. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1: August 12, 2010 747-56A2012

35 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 1: NO. 2 AND NO. 3 WINDOW IDENTIFICATION

(SHEET 1 OF 4)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

36 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 1: NO. 2 AND NO. 3 WINDOW IDENTIFICATION

(SHEET 2 OF 4)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

37 of 52

BOEING SERVICE BULLETIN 747-56A2012
The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY

numbers shown below are the number of parts necessary for each airplane.

NOTE: The window part number can be found on the manufacturer's nameplate, which should be

located along the upper edge of the window, on the inboard surface of the window or window

edging.

1.

2. If the window part number cannot be found, the following may be used to help distinguish

between the different windows:

— Acrylic windows (Part Number 65B07639-( ) and 65B07640-( ) ) do not have a window

edging or metal insert as is found on the single structural glass pane windows (Part

Number 65B027042-( ), 65B27043-( ), 65B27046-( ), and 65B27046-( ) ) and dual structural

glass pane windows (Part Number 141U4821-( ), 141U4822-( ), 141U4831-(), and

141U4832-( ) ).

— Dual structural glass pane windows have wire grid temperature sensors embedded in

the interlayer between glass panes. For No. 2 windows, these sensors are located along

the forward edge; and for No. 3 windows, these sensors are located along the aft edge.

— On acrylic windows, one of the thermal sensors is recessed into the inner ply. On single

and dual structural glass pane windows, both thermal sensors are surface mounted.

— On single and dual structural glass pane windows, there will be a small surface mounted

plastic ring around one of the thermal sensors to hold it in place. The plastic ring is not

used on acrylic windows.

— The 65B27042-( ) and 65B27043-( ) single structural glass pane windows have internal

tape that is visible around the periphery of the window. The internal tape is nearly

transparent, but may include visible wrinkles, particularly in the corners of the windows.

The internal tape does not exist on; 65B27046-( ) and 65B27047-( ) single structural glass

pane windows; 65B07639-( ) and 65B07640-( ) acrylic windows; 141U4821-( ),

141U4822-(), 141U4831-( ), and 141U4832-( ) dual structural glass pane windows.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Refer to 747-100/200/300

AMM 25-15-02 or 747-400

AMM 25-15-02 as accepted

procedures.

1 Remove / Keep Crash Pads - 4

Refer to 747-100/200/300

AMM 25-13-03 or 747-400

AMM 25-13-03 as accepted

procedures.

2 Remove / Keep Visor Track - 2

No. 3 Window Sun- - 2 -

shade

3 Remove / Keep

Common to the No. 1, No.

2, and No. 3 windows.

4 Remove / Keep Upper Molding - 2

5 Remove / Keep Sidewall Lining - 2 -

FIGURE 1: NO. 2 AND NO. 3 WINDOW IDENTIFICATION

(SHEET 3 OF 4)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

38 of 52

BOEING SERVICE BULLETIN 747-56A2012
STEP TASK NAME IDENTIFICATION QTY MORE DATA

65B27043-1 or 1 of Left No. 3 Window

65B27047-1 or

65B07640-1 or

65B07640-19 or

141U4831-1 or

141U4832-11 (a)

6 Record Part Number

65B27042-1 or 1 of Left No. 2 Window

65B27046-1 or

65B07639-1 or

65B07639-19 or

141U4821-11 or

141U4822-11 (b)

7 Record Part Number

65B27042-2 or 1 of Right No. 2 Window

65B27046-2 or

65B07639-2 or

65B07639-20 or

141U4821-12 or

141U4822-12 (c)

8 Record Part Number

65B27043-2 or 1 of Right No. 3 Window

65B27047-2 or

65B07640-2 or

65B07640-20 or

141U4831-2 or

141U4832-12 (d)

9 Record Part Number

10 Install Sidewall Lining (Kept) - 2 -

11 Install Upper Molding (Kept) - 2 -

No. 3 Window Sun- - 2 -

shade (Kept)

12 Install

Refer to 747-100/200/300

AMM 25-13-03 or 747-400

AMM 25-13-03 as accepted

procedures.

13 Install Visor Track (Kept) - 2

Refer to 747-100/200/300

AMM 25-15-02 or 747-400

AMM 25-15-02 as accepted

procedures.

14 Install Crash Pads (Kept) - 4

(a) If the window cannot be identified, assume the part number is 65B27043-1.

(b) If the window cannot be identified, assume the part number is 65B27042-1.

(c) If the window cannot be identified, assume the part number is 65B27042-2.

(d) If the window cannot be identified, assume the part number is 65B27043-2.

FIGURE 1: NO. 2 AND NO. 3 WINDOW IDENTIFICATION

(SHEET 4 OF 4)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

39 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 1 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

40 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 2 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

41 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 3 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

42 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 4 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

43 of 52

BOEING SERVICE BULLETIN 747-56A2012
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Left No. 3 Window - 1 (a) (b) (c) (d)

FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 5 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

44 of 52

BOEING SERVICE BULLETIN 747-56A2012
STEP TASK NAME IDENTIFICATION QTY MORE DATA

2 Inspect Left No. 2 Window - 1 (a) (b) (c) (d)

3 Inspect Right No. 2 Window - 1 (a) (b) (c) (d)

4 Inspect Right No. 3 Window - 1 (a) (b) (c) (d)

(a) Do an internal detailed inspection of the flight deck window for the following cracks or damage: fail-safe

interlayer cracks, glass pane cracks and chips, and indications of arcing. An optional external detailed

inspection of the flight deck window for the damage may be necessary if the existing window conditions

do not allow complete inspection from the inside of the flight deck. Any non-clear damage should be noted

that may hinder inspection of the damage.

(b) Inspect the window for vinyl fail-safe interlayer cracks along the metal edge insert and along the edge of

the release tape. Vinyl fail-safe interlayer cracks can be at any location in the window, but are usually

found along the metal edge insert and along the edge of the release tape.

(c) Inspect the window for glass pane cracks and chips. There are many types of chips but pay particular

attention to "V" shaped chips and peel chips. "V" shaped chips occur on the external surface of the glass

pane and have a sharp narrow "V" where the depth is equal to or larger than the width. Peel chips occur

on the internal surface of the glass pane and these areas have a curved, rough grained shape, and are

easily seen in reflected light. The area of the peel chips can have small glass flakes, usually white, and

view through the window will distort through the rough surface of the chip. Peel chips start very small but

can continue to grow with the continued use of the airplane.

(d) Inspect the window for any indications of arcing. An arc can occur due to an electrical discharge or short

circuit across a wire, bus bar, conductive heating film or other internal window components. Arcs usually

occur near the window bus bars, and are typically the result of moisture ingress. The heat from an arc

can cause dark brown or black burn marks on the bus bar and in the interlayer. Arcs in the heating film

away from the bus bar can occur as a jagged line.

The flag note number shown below agrees with the number shown in the flag symbols in the figure.

FLAG MORE DATA

NOTE

Color photographs of typical single structural glass pane No. 2 and No. 3 window damage can

be found in Fleet Team Digest Articles 747 FTD 56-05001 and 747-400 FTD 56-05001. These

articles can be accessed through the MyBoeingFleet website, or you may obtain copies from

your local Boeing Field Service office.

1

FIGURE 2: 65B27042-( ) AND 65B27043-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 6 OF 6)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

45 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 1 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

46 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 2 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

47 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 3 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

48 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 4 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

49 of 52

BOEING SERVICE BULLETIN 747-56A2012
FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 5 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

50 of 52

BOEING SERVICE BULLETIN 747-56A2012
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Left No. 3 Window - 1 (a) (b) (c) (d) (e)

FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 6 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

51 of 52

BOEING SERVICE BULLETIN 747-56A2012
STEP TASK NAME IDENTIFICATION QTY MORE DATA

2 Inspect Left No. 2 Window - 1 (a) (b) (c) (d) (e)

3 Inspect Right No. 2 Window - 1 (a) (b) (c) (d) (e)

4 Inspect Right No. 3 Window - 1 (a) (b) (c) (d) (e)

(a) Do an internal detailed inspection of the flight deck window for the following cracks or damage: fail-safe

interlayer cracks, glass pane cracks and chips, and indications of arcing. An optional external detailed

inspection of the flight deck window for the damage may be necessary if the existing window conditions

do not allow complete inspection from the inside of the flight deck. Any non-clear damage should be noted

that may hinder inspection of the damage.

(b) Inspect the window for fail-safe interlayer cracks along the metal edge insert. Fail-safe interlayer cracks

can be at any location in the window, but are usually found along the metal edge insert. As of the issue

date of this service bulletin, on 65B27046-( ) and 65B27047-( ) single structural glass pane No. 2 and No.

3 windows cracks have only been found in the inboard urethane fail-safe interlayer. No cracks have been

found in the vinyl fail-safe interlayer. The inboard urethane fail-safe interlayer cracks that have been found

do not run parallel to the edges of the window. Instead, they appear to be in random in directions close

to the window attachment bolt holes. Inboard urethane fail-safe interlayer cracks are frequently accompanied

by white or yellow discoloration of the urethane.

(c) On 65B27046-( ) and 65B27047-( ) single structural glass pane No. 2 and No. 3 windows, the outboard

urethane interlayer is considered to be non-structural. This layer is 0.02 inch thick and is located adjacent

to the outer glass pane. White or yellow discoloration and cracking in this layer is considered to be acceptable, as long as the pilot's vision is not obscured.

(d) Inspect the window for glass pane cracks and chips. There are many types of chips but pay particular

attention to "V" shaped chips and peel chips. "V" shaped chips occur on the external surface of the glass

pane and have a sharp narrow "V" where the depth is equal to or larger than the width. "V" shaped chips

occur on the external surface of the glass pane and have a sharp narrow "V" where the depth is equal to

or larger than the width. Peel chips occur on the internal surface of the glass pane and these areas have

a curved, rough grained shape, and are easily seen in reflected light. The area of the peel chips can have

small glass flakes, usually white, and view through the window will distort through the rough surface of

the chip. Peel chips start very small but can continue to grow with the continued use of the airplane.

(e) Inspect the window for any indications of arcing. An arc can occur due to an electrical discharge or short

circuit across a wire, bus bar, conductive heating film or other internal window components. Arcs usually

occur near the window bus bars, and are typically the result of moisture ingress. The heat from an arc

can cause dark brown or black burn marks on the bus bar and in the interlayer. Arcs in the heating film

away from the bus bar can occur as a jagged line.

The flag note number shown below agrees with the number shown in the flag symbols in the figure.

FLAG MORE DATA

NOTE

Color photographs of typical single structural glass pane No. 2 and No. 3 window damage can

be found in Fleet Team Digest Articles 747 FTD 56-05001 and 747-400 FTD 56-05001. These

articles can be accessed through the MyBoeingFleet website, or you may obtain copies from

your local Boeing Field Service office.

1

FIGURE 3: 65B27046-( ) AND 65B27047-( ) SINGLE STRUCTURAL GLASS PANE NO. 2 AND NO. 3 WINDOW

DETAILED INSPECTION

(SHEET 7 OF 7)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: August 24, 2006

Revision 1 August 12, 2010 747-56A2012

52 of 52

BOEING SERVICE BULLETIN 747-56A2012