Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-54A2237

Original Issue: March 14, 2013

ATA System: 5410

SUBJECT: NACELLES/PYLONS - Nacelle Strut - Outboard Struts GE CF6-45/50 and JT9D-70

Series Engines - Lower Spar Inspection and Modification

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

CFR 300-774). 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 © 2013 Boeing.

Unpublished Work. All Rights Reserved.

Treatment of this document and its content is governed by contract with Boeing. Rights to use this document

are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The

Boeing Company.

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BLANK PAGE
Table of Contents

Summary ...................................................... 5

1. PLANNING INFORMATION ........................................ 9

A. Effectivity ................................................ 9

1. Airplanes ............................................. 9

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 17

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 20

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 21

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

FIGURE 1: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION . . . 28

FIGURE 2: STRUT NO. 1 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION . . . . . . . 31

FIGURE 3: STRUT NO. 1 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT . 34

FIGURE 4: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION . . . 38

FIGURE 5: STRUT NO. 4 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION . . . . . . . 41

FIGURE 6: STRUT NO. 4 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT . 44

FIGURE 7: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET INSPECTION . . . . . . . . . 48

FIGURE 8: STRUT NO. 1 - INTERIOR SURFACES DET INSPECTION . . . . . . . . . . . . . . . . . 51

FIGURE 9: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET INSPECTION . . . . . . . . . 54

FIGURE 10: STRUT NO. 4 - LOWER SPAR WEB - INTERIOR SURFACES DET INSPECTION . . . . 57

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BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Summary Number: 747-54A2237

Original Issue: March 14, 2013

ATA System: 5410

SUBJECT: NACELLES/PYLONS - Nacelle Strut - Outboard Struts GE CF6-45/50 and JT9D-70

Series Engines - Lower Spar Inspection and Modification

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Accomplishment of this inspection or change will reduce the possibility of having severed lower spar chords.

Lower spar chords that are severed can result in reduced structural integrity of the diagonal brace load path.

Loss of the diagonal brace load path could compromise the strut to wing attachment which can result in the

separation of a strut and engine from the airplane during flight.

One operator reported finding both lower chords and the web on outboard strut no. 1 cracked at Nac. Sta. 300

on a strut with approximately 41,300 flight-cycles and 63,300 flight-hours. It is believed that the cracking was

due to fatigue from normal operating loads. The chords are the main load path for the diagonal brace attach

fitting. If the chord severs completely, it would reduce the structural integrity of the diagonal brace load path.

Loss of the diagonal brace load path could compromise the strut to wing attachment.

Detailed (DET) and High Frequency Eddy Current (HFEC) inspection of the web and chords will detect a crack

prior to the load path being compromised. Accomplishment of the modification will remove fatigue damaged

material and zero-time the holes in the chords. Zero-timing the holes will terminate the HFEC inspections of the

chords.

Boeing Service Related Problem (SRP) 747-SRP-54-0143 is related to this service bulletin.

Boeing Fleet Team Digest (FTD) 747 FTD 54-12001 is related to this service bulletin.

This table is provided to operators for planning purposes only. Refer to the applicable sections for more

information.

Planning Data Affected Reference

Spares Affected No Paragraph 1.A.2., Spares Affected

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Planning Data Affected Reference

Paragraph 1.E., Compliance and Paragraph

1.F., Approval

AD Related Yes

Weight and Balance Change No Paragraph 1.H., Weight and Balance Changes

Electrical Load Changed No Paragraph 1.I., Electrical Load Data

Publications Affected Yes Paragraph 1.K., Publications Affected

Airplane Flight Operations Affected (Flight Crew No Paragraph 1.K., Publications Affected

Operations Manual and/or FAA Approved Airplane Flight Manual)

Kits/Parts Required Yes Paragraph 2.C.1., Kits/Parts

Paragraph 2.C.2., Parts and Materials Supplied

by the Operator

Operator Supplied Parts/Material Yes

Paragraph 2.F., Special Tooling Necessary to

do this Service Bulletin

Special Tooling Required No

ACTION

PART 1: LOWER SPAR DET AND HFEC INSPECTION

Open access panels to gain access to the interior of the strut. Open the side cowls to gain access to the bottom

of the strut. Do a Detailed (DET) and High Frequency Eddy Current (HFEC) inspection of the lower chords for

cracks and a DET of the web for cracks from the bottom of the strut. Close the side cowls. Do a DET inspection

of the lower chords and the web for cracks from inside the strut. Close access panels.

PART 2: LOWER SPAR CHORD MODIFICATION

Open access panels to gain access to the interior of the strut. Remove left side cowl or open the side cowls to

gain access to the bottom of the strut. Remove the critical fasteners. Do an open-hole HFEC inspection of the

holes for cracks. Oversize holes (insurance cut) to remove fatigue damaged material. Install oversize fasteners.

Install the left side cowl or close the side cowls. Close access panels.

PART 3: LOWER SPAR REPAIR

Repair any part with crack in accordance with the Structural Repair Manual or contact The Boeing Company

for repair instructions for the lower spar chords and do the repair.

PART 4: LOWER SPAR DET INSPECTION

Open access panels to gain access to the interior of the strut. Open the side cowls to gain access to the bottom

of the strut. Do a Detailed (DET) inspection of the web and chords for cracks from the bottom of the strut. Close

the side cowls. Do a DET inspection of the web and chords for cracks from inside the strut. Close access panels.

EFFECTIVITY

747-200B, -200C, -200F, -300 and SR Airplanes powered by GE CF6-45/50 Series engines and PW JT9D-70

engines. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes

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ALERT ALERT
COMPLIANCE

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service

bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin

mandatory.

Refer to Paragraph 1.E., Compliance.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures

given in this service bulletin.

MANPOWER

Task Hours Elapsed Time

PART 1: LOWER SPAR DET AND HFEC INSPECTION 26.50 15.25

PART 2: LOWER SPAR CHORD MODIFICATION 10.50 10.50

PART 3: LOWER SPAR REPAIR (a) (a)

PART 4: LOWER SPAR DET INSPECTION 26.50 15.25

(a) No estimate given. Task Hours and Elapsed Hours depend on the scope of the repair which is variable.

MATERIAL INFORMATION

Boeing Supplied Kits/Parts.

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

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Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-54A2237

Original Issue: March 14, 2013

ATA System: 5410

SUBJECT: NACELLES/PYLONS - Nacelle Strut - Outboard Struts GE CF6-45/50 and JT9D-70

Series Engines - Lower Spar Inspection and Modification

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

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

Serial Number data.

This service bulletin is for the airplane(s) shown below.

GROUP CONFIGURATION DESCRIPTION

747-200B, -200C, -200F, -300, and SR Airplanes line numbers 202

through 886 powered by GE CF6-45/50 Series or JT9D-70 Series

engines.

1 -

Airplane Models:

747-200B, 747-200C, 747-200F, 747-300, 747SR

Variable Number Group

RB013 - RB016 1

RB681 - RB697 1

RD044 1

RD171 - RD172 1

RD181 - RD183 1

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Variable Number Group

RD231 - RD235 1

RD271 - RD272 1

RD291 - RD292 1

RD361 - RD366 1

RD381 - RD383 1

RD411 - RD414 1

RD451 - RD456 1

RD461 1

RD561 1

RD581 - RD583 1

RD591 - RD592 1

RD601 - RD607 1

RD641 - RD649 1

RD651 - RD659 1

RD661 1

RD691 - RD692 1

RD701 - RD702 1

RD721 - RD722 1

RD751 - RD755 1

RD771 - RD775 1

RD791 - RD792 1

RJ321 - RJ322 1

RJ331 - RJ333 1

RR202 - RR206 1

RR221 - RR224 1

RR301 - RR310 1

RR331 - RR332 1

RR421 1

RR551 - RR556 1

RR561 1

RS201 1

RS711 - RS713 1

RS721 - RS722 1

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ALERT ALERT
Variable Number Group

RS751 - RS752 1

RS761 - RS762 1

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of this inspection or change will reduce the possibility of having severed lower spar

chords. Lower spar chords that are severed can result in reduced structural integrity of the diagonal

brace load path. Loss of the diagonal brace load path could compromise the strut to wing attachment

which can result in the separation of a strut and engine from the airplane during flight.

One operator reported finding both lower chords and the web on outboard strut no. 1 cracked at Nac.

Sta. 300 on a strut with approximately 41,300 flight-cycles and 63,300 flight-hours. It is believed that

the cracking was due to fatigue from normal operating loads. The chords are the main load path for

the diagonal brace attach fitting. If the chord severs completely, it would reduce the structural integrity

of the diagonal brace load path. Loss of the diagonal brace load path could compromise the strut to

wing attachment.

Detailed (DET) and High Frequency Eddy Current (HFEC) inspection of the web and chords will detect

a crack prior to the load path being compromised. Accomplishment of the modification will remove

fatigue damaged material and zero-time the holes in the chords. Zero-timing the holes will terminate

the HFEC inspections of the chords.

Boeing Service Related Problem (SRP) 747-SRP-54-0143 is related to this service bulletin.

Boeing Fleet Team Digest (FTD) 747 FTD 54-12001 is related to this service bulletin.

D. Description

PART 1: LOWER SPAR DET AND HFEC INSPECTION

Open access panels to gain access to the interior of the strut. Open the side cowls to gain access to

the bottom of the strut. Do a Detailed (DET) and High Frequency Eddy Current (HFEC) inspection of

the lower chords for cracks and a DET of the web for cracks from the bottom of the strut. Close the

side cowls. Do a DET inspection of the lower chords and the web for cracks from inside the strut. Close

access panels.

PART 2: LOWER SPAR CHORD MODIFICATION

Open access panels to gain access to the interior of the strut. Remove left side cowl or open the side

cowls to gain access to the bottom of the strut. Remove the critical fasteners. Do an open-hole HFEC

inspection of the holes for cracks. Oversize holes (insurance cut) to remove fatigue damaged material.

Install oversize fasteners. Install the left side cowl or close the side cowls. Close access panels.

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ALERT ALERT
PART 3: LOWER SPAR REPAIR

Repair any part with crack in accordance with the Structural Repair Manual or contact The Boeing

Company for repair instructions for the lower spar chords and do the repair.

PART 4: LOWER SPAR DET INSPECTION

Open access panels to gain access to the interior of the strut. Open the side cowls to gain access to

the bottom of the strut. Do a Detailed (DET) inspection of the web and chords for cracks from the bottom

of the strut. Close the side cowls. Do a DET inspection of the web and chords for cracks from inside

the strut. Close access panels.

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

Affected Maintenance Zones

Model Zone

747-200B, 747-200C, 747-200F, 453, 483

747-300, 747SR

E. Compliance

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to

this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this

service bulletin mandatory.

When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When

more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION

numbers for that CONDITION number or OPTION number.

The Conditions, Actions and Compliance times shown apply to each strut independently.

Do the required actions in accordance with Paragraph 3. Accomplishment Instructions.

Table 1: Lower Spar Chord and Web, Detailed (DET) and High Frequency Eddy Current (HFEC) Inspection

before the accomplishment of PART 2: LOWER SPAR CHORD MODIFICATION

Repeat Interval (Not to Exceed)Compliance Time (Whichever Occurs

Later)

Condition Action

Within 120 days af- -

ter the original issue date of this

service bulletin.

Before 20,000 total

flight-cycles on the

strut.

Do PART 1: LOWER SPAR DET

AND HFEC INSPECTION for

cracks.

All Airplanes

Within 36 Months -

after the original issue date of this

service bulletin.

Before 20,000 total

flight-cycles on the

strut.

Do PART 1: LOWER SPAR DET

AND HFEC INSPECTION for cracks

and PART 2: LOWER SPAR

CHORD MODIFICATION. (a)

All Airplanes

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ALERT ALERT
Table 1: Lower Spar Chord and Web, Detailed (DET) and High Frequency Eddy Current (HFEC) Inspection

before the accomplishment of PART 2: LOWER SPAR CHORD MODIFICATION

Repeat Interval (Not to Exceed)Compliance Time (Whichever Occurs

Later)

Condition Action

600 flight-cycles.OPTION 1: Repeat PART 1: LOW- - -

ER SPAR DET AND HFEC INSPECTION for cracks.

CONDITION 1:

NO CRACK

FOUND

Within 600 flight- - -

cycles from the last

PART 1: LOWER

SPAR DET AND

HFEC INSPECTION.

OPTION 2: Do PART 1: LOWER

SPAR DET AND HFEC INSPECTION for cracks and PART 2: LOWER SPAR CHORD MODIFICATION.

(a)

Before further - -

flight.

CONDITION 2 (ACTION 1): Repair

any part with crack in accordance

with PART 3: LOWER SPAR REPAIR.

CONDITION 2:

ANY CRACK

FOUND

Before further - -

flight.

CONDITION 2 (ACTION 2): Do

PART 2: LOWER SPAR CHORD

MODIFICATION. (a)

(a) Accomplishing PART 1: LOWER SPAR DET AND HFEC INSPECTION at the same time as PART 2:

LOWER SPAR CHORD MODIFICATION terminates the PART 1: LOWER SPAR DET AND HFEC INSPECTION. See Table 2: Lower Spar Web, Detailed (DET) Inspection after accomplishment of PART 2:

LOWER SPAR CHORD MODIFICATION for inspections required after the accomplishment of PART 2:

LOWER SPAR CHORD MODIFICATION.

Table 2: Lower Spar Web, Detailed (DET) Inspection after the accomplishment of PART 2: LOWER SPAR

CHORD MODIFICATION

Repeat Interval (Not to Exceed)Compliance Time (Whichever Occurs

Later)

Condition Action

Within 18 months - -

after accomplishment of PART 2:

LOWER SPAR

CHORD MODIFICATION.

Do PART 4: LOWER SPAR DET

INSPECTION for cracks.

All Airplanes

Repeat PART 4: LOWER SPAR - - 18 months.

DET INSPECTION for cracks.

CONDITION 3:

NO CRACK

FOUND

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ALERT ALERT
Table 2: Lower Spar Web, Detailed (DET) Inspection after the accomplishment of PART 2: LOWER SPAR

CHORD MODIFICATION

Repeat Interval (Not to Exceed)Compliance Time (Whichever Occurs

Later)

Condition Action

Before further - -

flight.

CONDITION 4 (ACTION 1): Repair

in accordance with PART 3: LOWER

SPAR REPAIR.

CONDITION 4:

ANY CRACK

FOUND

Within 18 months - 18 months.

after PART 3:

LOWER SPAR REPAIR was accomplished.

CONDITION 4 (ACTION 2): Do

PART 4: LOWER SPAR DET INSPECTION for cracks.

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.

G. Manpower

The table below shows an estimate of the task hours necessary to do this inspection and change 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:

• Time to adjust to the workplace

• Time to schedule the work

• Time to inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

PART 1: LOWER SPAR DET AND HFEC INSPECTION

Number of Per- Task Hours Elapsed Hours

sons

Task

Open Access 1 1.00 1.00

Inspect Exterior (from bottom of strut)

...Strut No. 1 - FIGURE 1 2 4.00 2.00

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PART 1: LOWER SPAR DET AND HFEC INSPECTION

Number of Per- Task Hours Elapsed Hours

sons

Task

...Strut No. 4 - FIGURE 4 2 4.00 2.00

Inspect Interior

...Strut No. 1 - FIGURE 2 2 7.25 3.63

...Strut No. 4 - FIGURE 5 2 7.25 3.63

Close Access 1 1.00 1.00

TOTAL FOR EACH STRUT 13.25 7.63

TOTAL FOR EACH AIRPLANE 26.50 15.25

PART 2: LOWER SPAR CHORD MODIFICATION

Number of Per- Task Hours Elapsed Hours

sons

Task

Open Access 1 1.00 1.00

Remove fastener, inspect hole, and install fastener.

...Strut No. 1 - FIGURE 3 1 3.25 3.25

...Strut No. 4 - FIGURE 6 1 3.25 3.25

Close Access 1 1.00 1.00

TOTAL FOR EACH STRUT 5.25 5.25

TOTAL FOR EACH AIRPLANE 10.50 10.50

PART 3: LOWER SPAR REPAIR

Number of Per- Task Hours Elapsed Hours

sons

Task

Repair Chords

...Strut No. 1 (a) (a) (a)

...Strut No. 4 (a) (a) (a)

TOTAL FOR EACH STRUT (a) (a)

TOTAL FOR EACH AIRPLANE (a) (a)

(a) No estimate given. Number of Persons, Task Hours, and Elapsed Hours depend on the scope of the

repair which is variable.

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ALERT ALERT
PART 4: LOWER SPAR DET INSPECTION

Number of Per- Task Hours Elapsed Hours

sons

Task

Open Access 1 1.00 1.00

Inspect Exterior (from bottom of strut)

...Strut No. 1 - FIGURE 7 2 4.00 2.00

...Strut No. 4 - FIGURE 9 2 4.00 2.00

Inspect Interior

...Strut No. 1 - FIGURE 8 2 7.25 3.63

...Strut No. 4 - FIGURE 10 2 7.25 3.63

Close Access 1 1.00 1.00

TOTAL FOR EACH STRUT 13.25 7.63

TOTAL FOR EACH AIRPLANE 26.50 15.25

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. Boeing Service Related Problem (SRP) 747-SRP-54-0143

b. Service Bulletin Index D6-30300

c. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19

d. 747 Fleet Team Digest (FTD) 54-12001

e. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00

f. 747-100/200/300 Aircraft Maintenance Manual (AMM) 12-09-09, 71-11-04

g. 747-100/200/300 Structural Repair Manual (SRM) 54-11-03, 54-12-03

2. Data Supplied with this Service Bulletin:

None.

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

Drawing Number Title

65B94115 Spar Installation - LWR Aft (WL 1310), Outbd Nacelle

The table above lists applicable drawings used to prepare this service bulletin. The drawings are

not necessary to make the specified changes, and are not supplied with this service bulletin. The

drawings may not be applicable to all airplane configurations or operators.

K. Publications Affected

1. Publications:

Publication Chapter-Section

747 Illustrated Parts Catalog 54-41

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 affects FCS. DTI requirements for the structure affected

are contained in Paragraph 1.E., Compliance of this service bulletin.

L. Interchangeability and Intermixability of Parts

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

M. Software Accomplishment Summary

Not affected.

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ALERT ALERT

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

Boeing can supply the kit shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are

encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The

kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment.

Prices are in United States Dollars. Terms: Net 30 days.

Reference this service bulletin and submit your purchase order by one of these methods:

1. Order on-line via ATA Spec 2000 or The Boeing PART Page

2. Fax to (206) 662-7145

REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER

AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION

Unit Price as of

the original issue

date of this Service Bulletin (US

Dollars)

ROLT as of the

original issue

date of this Service Bulletin (Calendar Days)

Kit / Part Name Date QTY

Number

Top Kit - Outboard Strut January 8, 2013 1 139 $ 95.00

Lower Spar - GE CF6-45/50

/ JT9D-70 - Change

015U1940-1

March 12, 2013 1

65B94115-3 Chord - Outboard Strut February 5, 2013 3 (b) $6,540.00

(a)

65B94115-4 Chord - Outboard Strut February 5, 2013 3 (b) $6,540.00

(a)

(a) Required only if cracks are found and chord needs to be replaced.

(b) REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER

AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION

B. Industry Support Information

Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair

procedures given in this service bulletin.

C. Parts Necessary for Each Airplane

1. Kits/Parts

To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by

the Operator, are necessary for each airplane.

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ALERT ALERT
ALL

Kit 015U1940

Existing Part Notes

Number

New Part Number Qty Name

-1

Top Kit - Outboard

Strut Lower Spar -

GE CF6-45/50 /

JT9D-70 - Change

015U1940-1 -

BOLT, PROTRUD- (a)

ING HD

BACB30MB8A4U 12

BACC30BH8S 12 COLLAR (a)

(a) If grip length shown is not available at Boeing, fasteners supplied in kits

may be one grip length longer than indicated. Also, if any fasteners part

numbers listed are not available or have been superseded, substitute

fasteners may be supplied in kits.

2. Parts and Materials Supplied by the Operator

The following parts or materials are necessary to do the change in this service bulletin. Parts and

materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine

operator part and material supply to make sure all necessary parts and materials are available.

Part Number/ Specification Qty Name Notes

BMS 5-63 8 Oz Sealant (a)

(2) 14.6 X Sheet (b)

36.0

0.040 15-5 PH CRES SHEET,

HEAT TREAT 180 - 200 KSI

(Optional : 0.040 SHEET, BMS

7-240, Type 1 SOLUTION

TREATED 15-5 PH CRES,

HEAT TREAT 180 - 200 KSI)

65B94115-3 2 Chord - Outboard Strut - Left (c)

65B94115-4 2 Chord - Outboard Strut - Right (c)

(a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS)

for supplier data.

(b) Required only if cracks are found and web needs to be replaced. QTY is for airplane if

parts in both struts need replacement.

(c) Required only if cracks are found and chord needs to be replaced. QTY is for airplane if

parts in both struts need replacement.

3. Parts Modified and Reidentified

None.

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ALERT ALERT
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.

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ALERT ALERT

BLANK PAGE
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

– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch

– Angular tolerance is plus or minus 2 degrees

– Hole dimensions for standard solid rivets and fasteners are in Structural Repair

Manual (SRM) Chapter 51

– Torque limits to tighten nuts and bolts are in SRM Chapter 51

4. Use the approved fastener and process material substitutions in accordance with

SRM Chapter 51.

5. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures,

and SWPM 20-10-19 for the wire separation requirements, as accepted procedures.

6. The necessary conditions for selection of clamp type and size are included in SWPM

20-10-12. If any wire bundle support clamp specified in this service bulletin does not

make a correct fit on the wire bundle, refer to SWPM 20-10-12 as an accepted

procedure to select a clamp that fits correctly.

7. If the length of any fastener specified in this service bulletin does not meet installation

standards given in SRM Chapter 51, then a fastener of the same specification, or

an approved substitute, with a length which meets the installation standards given

in SRM Chapter 51 may be used. In addition, washers may be installed for fastener

grip length in accordance with SRM Chapter 51.

8. 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.

9. HFEC refers to a High Frequency Eddy Current Inspection. DET refers to a Detailed

Inspection.

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ALERT ALERT
10. These work instructions refer to procedures included in 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 "in

accordance with" are included in the instruction, the procedure in the Boeing document

must be used.

11. The instructions in Paragraph 3.B., Work Instructions and the figures can include

operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated

Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing

Index contain data on versions of the tools or test equipment that you can use. It is

permitted to use replaced tools. It is not permitted to use superseded tools.

12. If it is necessary to remove more parts for access, you can remove those parts. If

you can get access without removing identified parts, it is not necessary to remove

all of the identified parts. Jacking and shoring limitations must be observed.

13. Where the work instructions include installation of a kept part, a new or serviceable

part with the same part number can be installed as an alternative to the kept part.

14. This service bulletin includes functional test procedures for the systems changed by

this service bulletin. More functional tests can possibly be necessary in accordance

with standard maintenance practices because of interruption to other airplane systems.

15. Shaded areas in Figures are to separate the non-critical and non-authoritative

information from the critical and authoritative information.

16. When more than one OPTION is given for a CONDITION, do only one of the OPTION

numbers. When more than one ACTION is given for a CONDITION number or an

OPTION number, do all of the ACTION numbers for that CONDITION number or

OPTION number.

17. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS

are in Paragraph 1.E., Compliance.

18. The CONDITIONS, ACTIONS and OPTIONS shown apply to each strut independently.

B. WORK INSTRUCTIONS

Lower Spar chord and web, Detailed (DET) and High Frequency Eddy Current (HFEC) Inspection

before the accomplishment of PART 2: LOWER SPAR CHORD MODIFICATION

1. Do PART 1: LOWER SPAR DET AND HFEC INSPECTION for cracks.

2. Do PART 1: LOWER SPAR DET AND HFEC INSPECTION for cracks and PART 2: LOWER SPAR

CHORD MODIFICATION.

NOTE: PART 2: LOWER SPAR CHORD MODIFICATION is terminating action for PART 1:

LOWER SPAR DET AND HFEC INSPECTION. See Lower Spar Web, Detailed (DET)

Inspection after the accomplishment of PART 2: LOWER SPAR CHORD MODIFICATION

for inspections required after the accomplishment of PART 2: LOWER SPAR CHORD

MODIFICATION.

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ALERT ALERT
CONDITION 1: NO CRACK FOUND

a. OPTION 1: Repeat PART 1: LOWER SPAR DET AND HFEC INSPECTION for cracks.

b. OPTION 2: Do PART 1: LOWER SPAR DET AND HFEC INSPECTION for cracks and PART

2: LOWER SPAR CHORD MODIFICATION.

NOTE: PART 2: LOWER SPAR CHORD MODIFICATION is terminating action for PART 1:

LOWER SPAR DET AND HFEC INSPECTION. See Lower Spar Web, Detailed

(DET) Inspection after the accomplishment of PART 2: LOWER SPAR CHORD

MODIFICATION for inspections required after the accomplishment of PART 2:

LOWER SPAR CHORD MODIFICATION.

CONDITION 2: ANY CRACK FOUND

a. CONDITION 2 (ACTION 1): Repair any part with crack in accordance with PART 3: LOWER

SPAR REPAIR.

b. CONDITION 2 (ACTION 2): Do PART 2: LOWER SPAR MODIFICATION.

NOTE: PART 2: LOWER SPAR CHORD MODIFICATION is terminating action for PART 1:

LOWER SPAR DET AND HFEC INSPECTION. See Lower Spar Web, Detailed

(DET) Inspection after the accomplishment of PART 2: LOWER SPAR CHORD

MODIFICATION for inspections required after the accomplishment of PART 2:

LOWER SPAR CHORD MODIFICATION.

Lower Spar Web, Detailed (DET) Inspection after the accomplishment of PART 2: LOWER SPAR

CHORD MODIFICATION

1. Do PART 4: LOWER SPAR DET INSPECTION for cracks.

CONDITION 3: NO CRACK FOUND

a. Repeat PART 4: LOWER SPAR DET INSPECTION for cracks.

CONDITION 4: ANY CRACK FOUND

a. CONDITION 4 (ACTION 1): Repair in accordance with PART 3: LOWER SPAR REPAIR.

b. CONDITION 4 (ACTION 2): Do PART 4: LOWER SPAR DET INSPECTION for cracks.

PART 1: LOWER SPAR DET AND HFEC INSPECTION

1. Open access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

2. Open side cowl. Refer to 747-100/200/300 AMM 71-11-04 as an accepted procedure.

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ALERT ALERT
3. Do a DET and HFEC inspection for cracks in the lower spar chords and a DET of the web for

cracks in accordance with the figures below.

Strut no. 1 Strut no. 4

FIGURE 1 FIGURE 4

4. Close side cowl. Refer to 747-100/200/300 AMM 71-11-04 as an accepted procedure.

5. Do a DET inspection for cracks in the lower spar chords and web in accordance with the figures

below.

Strut no. 1 Strut no. 4

FIGURE 2 FIGURE 5

6. Close access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

7. Put airplane in serviceable condition.

PART 2: LOWER SPAR CHORD MODIFICATION

1. Open access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

2. Remove left side cowl (recommended),or open side cowls. Refer to 747-100/200/300 AMM 71-11-04

as an accepted procedure.

3. Replace fasteners in lower chords in accordance with the figures below.

Strut no. 1 Strut no. 4

FIGURE 3 FIGURE 6

4. Install left side cowl or close side cowls. Refer to 747-100/200/300 AMM 71-11-04 as an accepted

procedure.

5. Close access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

6. Put airplane in serviceable condition.

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ALERT ALERT
PART 3: LOWER SPAR REPAIR

1. Repair any crack in the lower spar web in accordance with 747-100/200/300 SRM 54-11-03

(CF6-45/50 series engines) or 747-100/200/300 SRM 54-12-03 (JT9D-70 series engines). Contact

The Boeing Company for repair instructions for the lower spar chords and do the repair.

PART 4: LOWER SPAR DET INSPECTION

1. Open access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

2. Open side cowl. Refer to 747-100/200/300 AMM 71-11-04 as an accepted procedure.

3. Do a DET inspection for cracks in the lower spar web and chord in accordance with the figures

below.

Strut no. 1 Strut no. 4

FIGURE 7 FIGURE 9

4. Close side cowl. Refer to 747-100/200/300 AMM 71-11-04 as an accepted procedure.

5. Do a DET inspection for cracks in the lower spar web and chord in accordance with the figures

below.

Strut no. 1 Strut no. 4

FIGURE 8 FIGURE 10

6. Close access panels below. Refer to 747-100/200/300 AMM 12-09-09 for location of panels.

Strut no. 1 Strut no. 4

453BL 483BL

7. Put airplane in serviceable condition.

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FIGURE 1: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 1 OF 3)

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FIGURE 1: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 2 OF 3)

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ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the indicated area for

cracks.

1 Inspect Lower Spar Chord - 2

Do a DET of the visible surfaces of

the indicated area for cracks.

2 Inspect Lower Spar Web - 1

Do a HFEC inspection for cracks of

the indicated area at the edge of the

chord in accordance with 747 NDT

Manual Part 6, 51-00-00, Procedure

13 or 24.

3 Inspect Lower Spar Chord - 2

Do a HFEC inspection for cracks

around the indicated fasteners in

accordance with 747 NDT Manual

Part 6, 51-00-00, Procedure 13 or

24.

4 Inspect Lower Spar Chord - 6

FIGURE 1: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 3 OF 3)

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FIGURE 2: STRUT NO. 1 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 1 OF 3)

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FIGURE 2: STRUT NO. 1 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 2 OF 3)

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ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the indicated area for

cracks.

1 Inspect Lower Spar Chord - 2

Do a DET of the visible surfaces of

the indicated area for cracks.

2 Inspect Lower Spar Web - 1

FIGURE 2: STRUT NO. 1 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 3 OF 3)

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FIGURE 3: STRUT NO. 1 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 1 OF 4)

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FIGURE 3: STRUT NO. 1 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 2 OF 4)

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ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

1 Remove Fastener - 6

Do an open-hole HFEC inspection

for cracks in the chord in accordance with 747 NDT Manual Part 6,

51-00-00, Procedure 2 or 19. (a)

2 Inspect Fastener Hole - 6

Do a full 1/16 inch oversize insurance cut. Contact The Boeing Company for repair instructions and do

the repair if oversize fasteners were

originally installed and the insurance

cut will exceed the hole size in the

fastener code table.

Drill / Fastener Hole - 6

Ream

3

Install Fastener - 6

(New)

4

Wet install fastener with sealant,

BMS 5-63.

Apply Sealant BMS 5-63 -

(a) If any crack is found, Contact The Boeing Company for repair instructions and do the repair.

The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

FIGURE 3: STRUT NO. 1 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 3 OF 4)

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Code Name Identification Qty Hole Dia More Data

Wet install with sealant,

BMS 5-63.

0.2495 -

0.2515

BOLT, PROTRUDING BACB30MB8A4U 6

HD

A

COLLAR BACC30BH8S 6 -

FIGURE 3: STRUT NO. 1 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 4 OF 4)

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FIGURE 4: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 1 OF 3)

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FIGURE 4: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 2 OF 3)

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ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the indicated area for

cracks.

1 Inspect Lower Spar Chord - 2

Do a DET of the visible surfaces of

the indicated area for cracks.

2 Inspect Lower Spar Web - 1

Do a HFEC inspection for cracks of

the indicated area at the edge of the

chord in accordance with 747 NDT

Manual Part 6, 51-00-00, Procedure

13 or 24.

3 Inspect Lower Spar Chord - 2

Do a HFEC inspection for cracks

around the indicated fasteners in

accordance with 747 NDT Manual

Part 6, 51-00-00, Procedure 13 or

24.

4 Inspect Lower Spar Chord - 6

FIGURE 4: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET AND HFEC INSPECTION

(SHEET 3 OF 3)

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ALERT ALERT
FIGURE 5: STRUT NO. 4 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 5: STRUT NO. 4 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 2 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the indicated area for

cracks.

1 Inspect Lower Spar Chord - 2

Do a DET of the visible surfaces of

the indicated area for cracks.

2 Inspect Lower Spar Web - 1

FIGURE 5: STRUT NO. 4 - LOWER SPAR - INTERIOR SURFACES DET INSPECTION

(SHEET 3 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 6: STRUT NO. 4 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 6: STRUT NO. 4 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

1 Remove Fastener - 6

Do an open-hole HFEC inspection

for cracks in the chord in accordance with 747 NDT Manual Part 6,

51-00-00, Procedure 2 or 19. (a)

2 Inspect Fastener Hole - 6

Do a full 1/16 inch oversize insurance cut. Contact The Boeing Company for repair instructions and do

the repair if oversize fasteners were

originally installed and the insurance

cut will exceed the hole size in the

fastener code table.

Drill / Fastener Hole - 6

Ream

3

Install Fastener - 6

(New)

4

Wet install fastener with sealant,

BMS 5-63.

Apply Sealant BMS 5-63 -

(a) If any crack is found, Contact The Boeing Company for repair instructions and do the repair.

The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

FIGURE 6: STRUT NO. 4 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
Code Name Identification Qty Hole Dia More Data

Wet install with sealant,

BMS 5-63.

0.2495 -

0.2515

BOLT, PROTRUDING BACB30MB8A4U 6

HD

A

COLLAR BACC30BH8S 6 -

FIGURE 6: STRUT NO. 4 - LOWER SPAR - HFEC INSPECTION AND FASTENER REPLACEMENT

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 7: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 7: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 2 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible surfaces

of the indicated area for cracks.

1 Inspect Lower Spar Web - 1

Do a DET of the visible surfaces

of the indicated area for cracks.

Inspect Lower Spar Chord - 2

FIGURE 7: STRUT NO. 1 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 3 OF 3)

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ALERT ALERT
FIGURE 8: STRUT NO. 1 - INTERIOR SURFACES DET INSPECTION

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 8: STRUT NO. 1 - INTERIOR SURFACES DET INSPECTION

(SHEET 2 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible surfaces

of the indicated area for cracks.

1 Inspect Lower Spar Web - 1

Do a DET of the visible surfaces

of the indicated area for cracks.

Inspect Lower Spar Chord - 2

FIGURE 8: STRUT NO. 1 - INTERIOR SURFACES DET INSPECTION

(SHEET 3 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 9: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 9: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 2 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible surfaces

of the indicated area for cracks.

1 Inspect Lower Spar Web - 1

Do a DET of the visible surfaces

of the indicated area for cracks.

Inspect Lower Spar Chord - 2

FIGURE 9: STRUT NO. 4 - LOWER SPAR - LOWER SURFACE DET INSPECTION

(SHEET 3 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 10: STRUT NO. 4 - LOWER SPAR WEB - INTERIOR SURFACES DET INSPECTION

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
FIGURE 10: STRUT NO. 4 - LOWER SPAR WEB - INTERIOR SURFACES DET INSPECTION

(SHEET 2 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT
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 side of airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible surfaces

of the indicated area for cracks.

1 Inspect Lower Spar Web - 1

Do a DET of the visible surfaces

of the indicated area for cracks.

Inspect Lower Spar Chord - 2

FIGURE 10: STRUT NO. 4 - LOWER SPAR WEB - INTERIOR SURFACES DET INSPECTION

(SHEET 3 OF 3)

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BOEING SERVICE BULLETIN 747-54A2237

ALERT ALERT