Commercial 

Airplanes 757

Service Bulletin

ALERT

Number: 757-52A0091

Original Issue: March 09, 2010

ATA System: 5232

SUBJECT: DOORS - Main Cargo Door - Cam Latch and Latch Pin Inspection and Modification

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

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laws.

ECCN: 9E991

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Unpublished Work - All Rights Reserved

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

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5.0
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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT

BLANK PAGE
Table of Contents

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 21

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 23

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 24

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION . . . . . . . . . 31

FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE MEASUREMENT . . . . . 34

FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT . . . . . . . . . . . . 36

FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION . . . . . . . . 38

FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT . . . . . . . . . . . 40

FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT . . . . . . . . . . . . . . . . . . . 42

FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT . . . . . . . . . . . . . . . . . . . . 45

FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION . . . . . . . . . . . 47

FIGURE 9: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION . . . . . . . . . 49

FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING . . . . . . . . . . . . . 51

FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT . . 54

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BLANK PAGE
Commercial 

Airplanes 757

Service Bulletin

ALERT

Summary Number: 757-52A0091

Original Issue: March 09, 2010

ATA System: 5232

SUBJECT: DOORS - Main Cargo Door - Cam Latch and Latch Pin 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 the inspections in this service bulletin will make sure the Main Cargo Door (MCD) cam latches

are inspected for wear and the latch pins are inspected for migration. The inspections are necessary in order

to find and replace worn cam latches, latch pins and latch pin attachment bolts. If not replaced, worn cam latches,

latch pins and latch pin attachment bolts could lead to a failure of the cam latches and may result in a possible

rapid decompression and potential separation of the cargo door from the airplane.

Boeing has received one report from one operator that the MCD forward most cam latch on the forward center

cam latch pair (cam latch number 3) broke during flight. The airplane that reported the broken cam latch had

20,000 flight hours and 9,500 flight cycles when the cam latch broke. The crew heard a loud noise coming from

the MCD shortly after cruise. Upon landing, an inspection was performed and a cam latch was found broken.

The broken cam latch mating latch pin was also found to have significant wear as evidenced by the loss of the

plating on the surface that is normally in contact with the cam. The latch pin was also deformed approximately

0.05 inch in the area of the wear surface.

The cause of the broken cam latch has been determined to be from a poorly rigged MCD. Although properly

rigged per the original Aircraft Maintenance Manual (AMM) procedures, significant variation was allowed in the

rigging dimensions. This variation can cause some of the latch pin/cam latch locations to have a significant

preload placed on them during engagement and rotation of the cam latches during latching and unlatching

operations. This preload is believed to have imparted a torque on the latch pin from the cam latch rotation during

latching and unlatching operations. The torque transmitted to the latch pin is then believed to have caused the

latch pin cross bolt to fail in shear. In addition, the cross bolt that attaches the latch pin had signs of corrosion

on the fracture surfaces.

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If the cross bolt fails, the latch pin could migrate either towards the cam latch or away from the cam latch. Latch

pin migration towards the cam latch can cause significant interference with the mating cam latch leading to cam

latch damage. In this case, the latch pin migrated into the cam latch and caused damage to the cam latch. The

crack initiated at the damage site caused by the latch pin and then lead to the cam latch breaking. Latch pin

migration away from the cam latch could cause disengagement from the cam latch, resulting in no load transfer

between the cam latch and the mating latch pin and may not be noticed before critical conditions are exceeded.

Accomplishment of the work given in this service bulletin will make sure the cam latches, latch pins and latch

pins cross bolts are inspected and replaced if wear is found. The MCD will also be re-rigged to the requirements

for door flushness, cam latch/latch pin concentricity, latch pin fitting forward/aft gap and shim thickness.

Boeing Service Related Problem (SRP) 757-SRP-52-0088 is related to this service bulletin.

ACTION

Get access to the MCD. Do a detailed inspection of the cam latches and latch pins. Check the torque of the

cross bolts in the latch pins. Measure the extension of the latch pins. Replace all alloy steel cross bolts through

the latch pins with Corrosion Resistant Steel (CRES) cross bolts. Do a High Frequency Eddy Current (HFEC)

or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for signs of cracks. Replace any cracked

or broken parts. Rig and check the MCD to the requirements for door flushness, cam latch/latch pin concentricity,

latch pin fitting forward/aft gap and shim thickness. Perform post rigging inspections in accordance with this

service bulletin.

EFFECTIVITY

757-200CB, 757-200PF and 757-200 Special Freighter delivered under a Boeing Supplemental Type Certificate

(STC) Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes.

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 inspections and modifications given in this service bulletin.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

Operator Supplied Parts/Materials.

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

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 757

Service Bulletin

ALERT

Number: 757-52A0091

Original Issue: March 09, 2010

ATA System: 5232

SUBJECT: DOORS - Main Cargo Door - Cam Latch and Latch Pin 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 Document D624N001 Part 3 for Airplane Variable Number, Line

Number, and Serial Number data.

This service bulletin is for the airplanes shown below.

GROUP CONFIGURATION DESCRIPTION

757-200PF, 757-200CB and 757-200 Special Freighter delivered

under a Boeing Supplemental Type Certificate (STC) Airplanes

1 -

Airplane Models:

757-200, 757-200CB, 757-200PF

Variable Number Group

NA201 - NA204 1

NA206 - NA213 1

NA215 - NA236 1

NC901 - NC951 1

NC971 1

NC973 - NC974 1

ND895 1

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Variable Number Group

NS601 - NS616 1

NT001 - NT009 1

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of the inspections in this service bulletin will make sure the Main Cargo Door (MCD)

cam latches are inspected for wear and the latch pins are inspected for migration. The inspections are

necessary in order to find and replace worn cam latches, latch pins and latch pin attachment bolts. If

not replaced, worn cam latches, latch pins and latch pin attachment bolts could lead to a failure of the

cam latches and may result in a possible rapid decompression and potential separation of the cargo

door from the airplane.

Boeing has received one report from one operator that the MCD forward most cam latch on the forward

center cam latch pair (cam latch number 3) broke during flight. The airplane that reported the broken

cam latch had 20,000 flight hours and 9,500 flight cycles when the cam latch broke. The crew heard

a loud noise coming from the MCD shortly after cruise. Upon landing, an inspection was performed

and a cam latch was found broken. The broken cam latch mating latch pin was also found to have

significant wear as evidenced by the loss of the plating on the surface that is normally in contact with

the cam. The latch pin was also deformed approximately 0.05 inch in the area of the wear surface.

The cause of the broken cam latch has been determined to be from a poorly rigged MCD. Although

properly rigged per the original Aircraft Maintenance Manual (AMM) procedures, significant variation

was allowed in the rigging dimensions. This variation can cause some of the latch pin/cam latch locations

to have a significant preload placed on them during engagement and rotation of the cam latches during

latching and unlatching operations. This preload is believed to have imparted a torque on the latch pin

from the cam latch rotation during latching and unlatching operations. The torque transmitted to the

latch pin is then believed to have caused the latch pin cross bolt to fail in shear. In addition, the cross

bolt that attaches the latch pin had signs of corrosion on the fracture surfaces.

If the cross bolt fails, the latch pin could migrate either towards the cam latch or away from the cam

latch. Latch pin migration towards the cam latch can cause significant interference with the mating cam

latch leading to cam latch damage. In this case, the latch pin migrated into the cam latch and caused

damage to the cam latch. The crack initiated at the damage site caused by the latch pin and then lead

to the cam latch breaking. Latch pin migration away from the cam latch could cause disengagement

from the cam latch, resulting in no load transfer between the cam latch and the mating latch pin and

may not be noticed before critical conditions are exceeded.

Accomplishment of the work given in this service bulletin will make sure the cam latches, latch pins

and latch pins cross bolts are inspected and replaced if wear is found. The MCD will also be re-rigged

to the requirements for door flushness, cam latch/latch pin concentricity, latch pin fitting forward/aft gap

and shim thickness.

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Boeing Service Related Problem (SRP) 757-SRP-52-0088 is related to this service bulletin.

D. Description

Get access to the MCD. Do a detailed inspection of the cam latches and latch pins. Check the torque

of the cross bolts in the latch pins. Measure the extension of the latch pins. Replace all alloy steel cross

bolts through the latch pins with CRES cross bolts. Do a HFEC or alternate magnetic particle inspection

of cam latch 1 and cam latch 2 for signs of cracks. Replace any cracked or broken parts. Rig and check

the MCD to the requirements for door flushness, cam latch/latch pin concentricity, latch pin fitting

forward/aft gap and shim thickness. Perform post rigging inspections in accordance with this service

bulletin.

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

Affected Maintenance Zones

Model Zone

757-200, 757-200CB, 757- 838

200PF

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.

Table 1: Initial (Pre-Rigging) Inspections of the Cam Latches and Latch Pins for the Main Cargo Door

(MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Within 330 flight -

cycles or 150 days

after the original issue date of this

service bulletin.

(whichever occurs

first)

Do the following for all MCD cam latches

and latch pins:

Do a detailed inspection of the cam

latches and latch pins in accordance with

Accomplishment Instruction 3.B.1.b.

And

Torque the cross bolts in the latch pins

in accordance with Accomplishment Instruction 3.B.1.c.

All airplanes

And

Measure the extension of the latch pins

in accordance with Accomplishment Instruction 3.B.1.d.

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 1: Initial (Pre-Rigging) Inspections of the Cam Latches and Latch Pins for the Main Cargo Door

(MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Replace all cracked or broken part(s) in Before further flight -

accordance with Accomplishment Instruction 3.B.2.a.

Inspection Condition 1 -

If the inspections reveal

one or more of the following: And

1. Cracked or

broken cam

latch(es)

2. Cracked or

broken latch

pin(s)

3. Broken latch

pin cross

bolt(s)

Unless replaced with new parts, do a

HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2

in accordance with Accomplishment Instruction 3.B.2.b.

And

Rig and check the MCD in accordance

with Accomplishment Instruction 3.B.2.c.

And

Replace all alloy steel cross bolts

through the latch pins with CRES cross

bolts in accordance with Accomplishment Instruction 3.B.2.c.

Within 330 flight -

cycles or 150 days

after the initial inspection (whichever occurs first)

Contact Boeing and provide a detailed

description of the cam latch deformations for rework instructions and perform

the applicable rework in accordance with

Accomplishment Instruction 3.B.3.a.(a)

Inspection Condition 2 -

If the inspections reveal

one or more of the following:

1. Local deformation of the cam

latch lip.

2. Flaking of the

chrome plating

on the cam

latch or latch

pin.

3. Wear of the

chrome plating

down to the

base material

of the cam

latch or latch

pin.

And

Replace all cam latches and latch pins

in accordance with Accomplishment Instruction 3.B.3.b.(b)

And

330 flight cycles or 150

days (whichever occurs first)

Within 330 flight

cycles or 150 days

after the initial inspection (whichever occurs first)

Do a detailed inspection of the cam

latches and latch pins in accordance with

Accomplishment Instruction 3.B.3.c.

And

Within 3000 flight -

cycles or 24

months after the

original issue date

of this service bulletin (whichever

occurs first)

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.3.d.

And

Rig and check the MCD in accordance

with Accomplishment Instruction 3.B.3.e.

And

Replace all alloy steel cross bolts

through the latch pins with CRES cross

bolts in accordance with Accomplishment Instruction 3.B.3.e.

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 1: Initial (Pre-Rigging) Inspections of the Cam Latches and Latch Pins for the Main Cargo Door

(MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Contact Boeing and provide a detailed Before further flight -

description of the inspection findings

(and photographs, if possible) in accordance with Accomplishment Instruction

3.B.4.a.

Inspection Condition 3 -

If the initial inspections

reveal one or more signs

of the following:

1. Corrosion of

the cam latch

or latch pin.

2. Gouges and/or

scrapes in the

cam latch or

latch pin

chrome plating

or base material.

3. Deformations

of the cam

latch or latch

pin.

4. Any other damage not identified in Inspection Conditions

1 and 2.

And

Contact Boeing for additional inspection

and/or repair instructions and perform

applicable inspection and/or repair in

accordance with Accomplishment Instruction 3.B.4.b.

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 1: Initial (Pre-Rigging) Inspections of the Cam Latches and Latch Pins for the Main Cargo Door

(MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Within 330 flight -

cycles or 150 days

after the initial inspection (whichever occurs first)

Replace the latch pin in accordance with

Accomplishment Instruction 3.B.5.a.(1).

And

Remove the mating cam latch and do a

detailed inspection in accordance with

Accomplishment Instruction 3.B.5.a.(2).

Inspection Condition 4.1

- If the latch pin extension is less that 0.84

inches or greater than

0.94 inches

And

Within 3000 flight -

cycles or 24

months after the

original issue date

of this service bulletin (whichever

occurs first)

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.5.a.(3).

And

Rig and check the MCD in accordance

with Accomplishment Instruction

3.B.5.a.(4).

And

Replace all alloy steel cross bolts

through the latch pins with CRES cross

bolts in accordance with Accomplishment Instruction 3.B.5.a.(4).

330 flight cycles or 150

days (whichever occurs first)

Within 330 flight

cycles or 150 days

after the initial inspection (whichever occurs first)

Do a detailed inspection of the cam

latches and latch pins in accordance with

Accomplishment Instruction 3.B.5.b.(1).

And

Inspection Condition 4.2

- If the latch pin extension is between 0.84

and 0.89 inches or between 0.91 and 0.94

inches Within 3000 flight -

cycles or 24

months after the

original issue date

of this service bulletin (whichever

occurs first)

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.5.b.(2).

And

Rig and check the MCD in accordance

with Accomplishment Instruction

3.B.5.b.(3).

And

Replace all alloy steel cross bolts

through the latch pins with CRES cross

bolts in accordance with Accomplishment Instruction 3.B.5.b.(3).

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 1: Initial (Pre-Rigging) Inspections of the Cam Latches and Latch Pins for the Main Cargo Door

(MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

330 flight cycles or 150

days (whichever occurs first)

Within 330 flight

cycles or 150 days

after the initial inspection (whichever occurs first)

Do a general visual inspection in accordance with Accomplishment Instruction

3.B.6.a.

And

Inspection Condition 5 -

If the inspections reveal

no signs of damage,

distress or incorrect rigging as described in Inspection Conditions 1

through 4. 3000 flights or 24

months (whichever occurs first)

Within 3000 flight

cycles or 24

months after the

initial inspection

(whichever occurs

first)

Do a detailed inspection of the cam

latches and latch pins in accordance with

Accomplishment Instruction 3.B.6.b.

And

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.6.c

And

Within 6000 flight -

cycles or 48

months after the

original issue date

of this service bulletin (whichever

occurs first)

Rig and check the MCD in accordance

with Accomplishment Instruction 3.B.6.d.

And

Replace all alloy steel cross bolts

through the latch pins with CRES cross

bolts in accordance with Accomplishment Instruction 3.B.6.d.

(a) Boeing recommends the operator provide a detailed description of the cam latch deformations (including

size and location, as well as the total number of flights the cam latch has been in service) so that Boeing

has time to determine rework instructions and the operator has time to organize the resources needed to

complete the changes within the applicable compliance period.

(b) There is a possibility the cam latch or latch pin can be refinished with new chrome plating. Before a cam

latch or latch pin can be reused, the operator must provide Boeing with a detailed description of the chrome

damage, including size and location, as well as the total number of flights the cam latch or latch pin has

been in service. Boeing will use this information to determine if the cam latch or latch pin can be refinished

and reused.

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 2: Repetitive Post-Rigging Inspections of the Cam Latches and Latch Pins for the Main Cargo

Door (MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

330 flight cycles or 150

days (whichever occurs first)

Within 330 flight

cycles or 150 days

after the MCD adjustment and check

(whichever occurs

first)

Do a general visual inspection in accordance with Accomplishment Instruction

3.B.7.a.(1).

And

All airplanes

3000 flights or 24

months (whichever occurs first)

Within 3000 flight

cycles or 24

months after the

MCD adjustment

and check

(whichever occurs

first)

Do a detailed inspection of the cam

latches and latch pins in accordance with

Accomplishment Instruction 3.B.7.a.(2).

And

6000 flights or 48

months (whichever occurs first)

Within 6000 flight

cycles or 48

months after the

MCD adjustment

and check

(whichever occurs

first)

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.7.a.(3).

Replace all cracked or broken part(s) in Before further flight -

accordance with Accomplishment Instruction 3.B.7.b.(1).

Post-rigging Inspection

Condition 1 - If the inspections reveal one or

more of the following: And

1. Cracked or

broken cam

latch(es)

2. Cracked or

broken latch

pin(s)

3. Broken latch

pin cross

bolt(s)

Unless replaced with new parts, do a

HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2

in accordance with Accomplishment Instruction 3.B.7.b.(2).

And

Rig and check the MCD in accordance

with Accomplishment Instruction

3.B.7.b.(3).

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 2: Repetitive Post-Rigging Inspections of the Cam Latches and Latch Pins for the Main Cargo

Door (MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Within 330 flight -

cycles or 150 days

after the post-rigging inspection

(whichever occurs

first)

Contact Boeing and provide a detailed

description of the cam latch deformations for rework instructions and perform

the applicable rework in accordance with

Accomplishment Instruction

3.B.7.c.(1).(a)

Post-rigging Inspection

Condition 2 - If the inspections reveal one or

more of the following:

1. Local deformation of the cam

latch lip.

2. Flaking of the

chrome plating

on the cam

latch or latch

pin.

3. Wear of the

chrome plating

down to the

base material

of the cam

latch or latch

pin.

And

Replace all cam latches and latch pins

in accordance with Accomplishment Instruction 3.B.7.c.(2).(b)

And

330 flight cycles or 150

days (whichever occurs first)

Within 330 flight

cycles or 150 days

after the post-rigging inspection

(whichever occurs

first)

Do a detailed inspection of the remaining

cam latches and latch pins in accordance with Accomplishment Instruction

3.B.7.c.(3).

And

Within 3000 flight -

cycles or 24

months after the

post-rigging inspection (whichever occurs first)

Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam

latch 2 in accordance with Accomplishment Instruction 3.B.7.c.(4).

And

Rig and check the MCD in accordance

with Accomplishment Instruction

3.B.7.c.(5).

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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
Table 2: Repetitive Post-Rigging Inspections of the Cam Latches and Latch Pins for the Main Cargo

Door (MCD)

Repeat Interval (Not

to Exceed)

Condition Action Compliance Time

Contact Boeing and provide a detailed Before further flight -

description of the inspection findings

(and photographs, if possible) in accordance with Accomplishment Instruction

3.B.7.d.(1).

Post-rigging Inspection

Condition 3 - If the inspections reveal one or

more signs of the following:

1. Corrosion of And

the cam latch

or latch pin.

2. Gouges and/or

scrapes in the

cam latch or

latch pin

chrome plating

or base material.

3. Deformations

of the cam

latch or latch

pin.

4. Any other damage not identified in Inspection Conditions

1 and 2.

Contact Boeing for additional inspection

and/or repair instructions and perform

applicable inspection and/or repair in

accordance with Accomplishment Instruction 3.B.7.d.(2).

(a) Boeing recommends the operator provide a detailed description of the cam latch deformations (including

size and location, as well as the total number of flights the cam latch has been in service) so that Boeing

has time to determine rework instructions and the operator has time to organize the resources needed to

complete the changes within the applicable compliance period.

(b) There is a possibility the cam latch or latch pin can be refinished with new chrome plating. Before a cam

latch or latch pin can be reused, the operator must provide Boeing with a detailed description of the chrome

damage, including size and location, as well as the total number of flights the cam latch or latch pin has

been in service. Boeing will use this information to determine if the cam latch or latch pin can be refinished

and reused.

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ALERT ALERT
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 the inspections and modifications

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.

Number of Per- Task Hours Elapsed Hours

sons

Task

Open Access 1 0.25 0.25

FIGURE 1 1 1.60 1.60

FIGURE 2 1 0.50 0.50

FIGURE 3 1 0.50 0.50

FIGURE 4 1 1.00(h) 1.00(h)

FIGURE 5 1 1.00 1.00

FIGURE 6 1(i) 0.50(a) (f) (i) 0.50(a) (f) (i)

FIGURE 7 1 0.10(b) (g) 0.10(b) (g)

FIGURE 8 1 0.60(c) 0.60(c)

FIGURE 9 1 0.10(d) 0.10(d)

FIGURE 10 - FIG- 2-3 48.0 20.0

URE 11

Close Access 1 0.25 0.25

TOTAL FOR EACH AIRPLANE (e) (e)

(a) Estimate is per cam latch requiring replacement.

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ALERT ALERT
Number of Per- Task Hours Elapsed Hours

sons

Task

(b) Estimate is per latch pin requiring replacement.

(c) Estimate is per cam latch requiring inspection.

(d) Estimate is per cam latch.

(e) Total time required may vary depending upon conditions found during inspections.

(f) Does not include time to match drill cam shaft.

(g) Does not include time to match drill latch pin

(h) Does not include NDI inspection time

(i) Cam latch 4 will require 2 hours and a second person to remove.

H. Weight and Balance Changes

Change in Moment

(Pound-Inches)

Change in Weight

Airplane (Pounds)

757-200CB Negligible Negligible

757-200PF Negligible Negligible

757-200 Special Negligible Negligible

Freighter

I. Electrical Load Data

Not changed.

J. References

1. Existing Data

a. Boeing Service Related Problem (SRP) 757-SRP-52-0088

b. Standard Overhaul Practices Manual (SOPM) 20-20-01

c. 757 Aircraft Maintenance Manual (AMM) 52-32-00

d. 757 Illustrated Parts Catalog (IPC) 53-33-63-03

e. 757 Non-Destructive Testing (NDT) Manual Part 6, 51-00-12 or 51-00-21

2. Data supplied with this Service Bulletin

None.

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BOEING SERVICE BULLETIN 757-52A0091

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

Drawing Number Title

65-25326 DOOR INSTALLATION - MAIN CARGO

65-25339 LATCH MECHANISM INSTALLATION - MAIN CARGO DOOR

143N8750 SILL INSTL - LOWER, MAIN CARGO DOOR

65-67872 LATCH PIN FITTING - ASSY

69-23438 CAM - LATCH MECHANISM CARGO DOOR

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

757 Illustrated Parts Catalog 757 IPC 53-33-63-03

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated 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.

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ALERT ALERT

BLANK PAGE
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 inspections and modifications given in this service

bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts

None.

2. Parts and Materials Supplied by the Operator

Part Number / QTY Name Existing Part Number Notes

Specification

BOLT, HEX HEAD, 160 KSI MIN NAS6603-24 (a) (b)

TENSILE, LONG THREAD, A286,

NONLOCKING

BACB30LM3-24 8

OR

BACB30LM3-22

OR

BACB30NF3-22

Parts are only needed if

existing part

cannot be reworked.

69-23438-2 - Cam Latch 1 69-23438-2

143N8060-1 - Cam Latch 2 143N8060-1

143N8027-2 - Cam Latch 3 143N8027-2

69-23439-3 - Cam Latch 4 69-23439-3

69-23439-4 - Cam Latch 5 69-23439-4

143N8027-1 - Cam Latch 6 143N8027-1

143N8060-2 - Cam Latch 7 143N8060-2

69-23438-1 - Cam Latch 8 69-23438-1

6-83137-2 - Latch Pin 6-83137-2

(a) Refer to 757 Structural Repair Manual Chapter 51 for alternate fasteners.

(b) BACB30LM3-24 and NAS6603-24 used if 143N8157-2 Clip Assembly is installed.

NOTE: Rubber Quicksetting Putty (G50673) is needed if the door rigging procedure per 757

AMM 52-32-00 20Sep2008 Revision is used.

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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BOEING SERVICE BULLETIN 757-52A0091

ALERT ALERT
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. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s)

give the recommended sequence of steps. The sequence of steps to do this service

bulletin can be changed.

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

definition of the acronyms.

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

4. 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

– Torque limits to tighten nuts and bolts are in 757 SRM, Chapter 51

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

757 SRM, Chapter 51. Alternate fasteners are listed in 757 SRM Chapter 51 and

Boeing Drawing 65-88700.

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

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

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

SRM Chapter 51 may be used.

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ALERT ALERT
7. 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.

8. A General Visual Inspection is defined as: A visual examination of an interior or

exterior area, installation or assembly to detect obvious damage, failure or irregularity.

This level of inspection is made from within touching distance unless otherwise

specified. A mirror may be necessary to ensure visual access to all surfaces in the

inspection area. This level of inspection is made under normal available lighting

conditions such as daylight, hangar lighting, flashlight or drop-light and may require

removal or opening of access panels or doors. Stands, ladders or platforms may be

required to gain proximity to the area being checked.

9. 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.

B. WORK INSTRUCTIONS

NOTE: It is important to do the following steps in the specified order.

1. Initial Inspections

a. Get access to the Main Cargo Door.

b. Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE 1.

c. Torque the cross bolts in the latch pins in accordance with FIGURE 2.

d. Measure the extension of the latch pins in accordance with FIGURE 3.

2. Inspection Condition 1:

If the inspections reveal one or more signs of the following:

– Cracked or broken cam latch(es)

– Cracked or broken latch pin(s)

– Broken latch pin cross bolts

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a. Replace cam latch in accordance with FIGURE 6, replace latch pin in accordance with FIGURE

7 and replace latch pin cross bolt in accordance with FIGURE 5.

b. Unless replaced with new parts, do a HFEC or alternate magnetic particle inspection of cam

latch 1 and cam latch 2 for signs of cracks in accordance with FIGURE 4. Address the

inspection findings as described in Inspection Condition 1.

c. Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and

replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance

with FIGURE 5. Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted procedure for

MCD rigging.

3. Inspection Condition 2:

If the inspections reveal one or more signs of the following:

– Local deformation of the cam latch lip

– Flaking of the chrome plating on the cam latch or latch pin

– Wear of the chrome plating down to the base material of the cam latch or latch pin

a. Contact Boeing and provide a detailed description of the cam latch deformations for rework

instructions and perform the applicable rework.

b. Replace all cam latches and latch pins with signs of flaking of the chrome plating or wear

down to the base material in accordance with FIGURE 6 and FIGURE 7.

c. Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE 1.

Address the inspection findings as described in Inspection Conditions 1 through 4.

d. Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for signs

of cracking in accordance with FIGURE 4. Address the inspection findings as described in

Inspection Condition 1.

e. Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and

replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance

with FIGURE 5. Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted procedure for

MCD rigging.

4. Inspection Condition 3:

If the inspections reveal one or more signs of the following:

– Corrosion of the cam latch or latch pin

– Gouges and/or scrapes in the cam latch or latch pin chrome plating or base material

– Deformations of the cam latch or latch pin

– Any other damage not identified in Inspection Conditions 1 and 2.

a. Contact Boeing and provide a detailed description of the inspection findings (and photographs,

if possible).

b. Contact Boeing for additional inspection and/or repair instructions and perform applicable

inspection and/or repair.

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ALERT ALERT
5. Inspection Condition 4:

a. Inspection Condition 4.1 - If the latch pin extension is less than 0.84 inches or greater than

0.94 inches:

(1) Replace the latch pin in accordance with FIGURE 7.

(2) Remove the mating cam latch and do a detailed inspection in accordance with FIGURE

8. Address the inspection findings as described in Inspection Condition 1.

(3) Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for

signs of cracking in accordance with FIGURE 4. Address the inspection findings as

described in Inspection Condition 1.

(4) Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11,

and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in

accordance with FIGURE 5. Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted

procedure for MCD rigging.

b. Inspection Condition 4.2 - If the latch pin extension is between 0.89 and 0.84 inches or between

0.91 and 0.94 inches:

(1) Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE

1. Address the inspection findings as described in Inspection Conditions 1 through 3.

(2) Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for

signs of cracking in accordance with FIGURE 4. Address the inspection findings as

described in Inspection Condition 1.

(3) Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11,

and replace all alloy steel cross bolts through the latch pins with CRES cross bolts in

accordance with FIGURE 5. Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted

procedure for MCD rigging.

NOTE: Rigging for the latch pin will require it to be installed properly with an extension

of 0.90 +/- 0.01 inches. A latch pin originally in condition 4.2 with no other

discrepancies may be re-used by clocking the latch pin 90 degrees +/- 10 degrees

from original position and match drilling a new cross bolt hole that provides the

correct latch pin extension. Fill old cross bolt hole in pin with BMS 5-95 sealant

and install pin with BMS 3-27 corrosion inhibiting compound.

6. Inspection Condition 5:

If the inspections reveal no signs of damage, distress, or incorrect rigging as described in Inspection

Conditions 1 through 4:

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ALERT ALERT
a. Do a general visual inspection of the cam latches and latch pins in accordance with FIGURE

9. Address the inspection findings as described in Inspection Condition 1.

b. Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE 1.

Address the inspection findings as described in Inspection Conditions 1 through 5.

c. Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for signs

of cracking in accordance with FIGURE 4. Address the inspection findings as described in

Inspection Condition 1.

d. Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11, and

replace all alloy steel cross bolts through the latch pins with CRES cross bolts in accordance

with FIGURE 5. Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted procedure for

MCD rigging.

7. Post-Rigging Inspections for Airplanes that have completed the Rig and Check of the Main Cargo

Door in accordance with FIGURE 10 and FIGURE 11:

a. Post-Rigging Inspection of all airplanes:

(1) Do a general visual inspection of the cam latches and latch pins in accordance with

FIGURE 9. Address the inspection findings as described in Inspection Condition 1.

(2) Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE

1. Address the inspection findings as described in Inspection Conditions 1 through 3.

(3) Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for

signs of cracking in accordance with FIGURE 4. Address the inspection findings as

described in Inspection Condition 1.

b. Post-rigging Inspection Condition 1:

If the post-rigging inspections reveal one or more of the following:

– Cracked or broken cam latch(es)

– Cracked or broken latch pin(s)

– Broken latch pin cross bolt(s)

(1) Replace cam latch in accordance with FIGURE 6, replace latch pin in accordance with

FIGURE 7 and replace latch pin cross bolt in accordance with FIGURE 5.

(2) Unless replaced with new parts, do a HFEC or alternate magnetic particle inspection of

cam latch 1 and cam latch 2 for signs of cracks in accordance with FIGURE 4. Address

the inspection findings as described in Inspection Condition 1.

(3) Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11.

Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted procedure for MCD rigging.

c. Post-rigging Inspection Condition 2:

If the post-rigging inspections reveal one or more of the following:

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– Local deformation of the cam latch lip

– Flaking of the chrome plating on the cam latch or latch pin

– Wear of the chrome plating down to the base material of the cam latch or latch pin

(1) Contact Boeing and provide a detailed description of the cam latch deformations for

rework instructions and perform the applicable rework.

(2) Replace all cam latches and latch pins with signs of flaking of the chrome plating or wear

down to the base material in accordance with FIGURE 6 and FIGURE 7.

(3) Do a detailed inspection of the cam latches and latch pins in accordance with FIGURE

1. Address the inspection findings as described in Inspection Conditions 1 through 3.

(4) Do a HFEC or alternate magnetic particle inspection of cam latch 1 and cam latch 2 for

signs of cracking in accordance with FIGURE 4. Address the inspection findings as

described in Inspection Condition 1.

(5) Rig and check the Main Cargo Door in accordance with FIGURE 10 and FIGURE 11.

Refer to 757 AMM 52-32-00 Rev 20Sep2008 as an accepted procedure for MCD rigging.

d. Post-rigging Inspection Condition 3:

If the post-rigging inspections reveal one or more of the following:

– Corrosion of the cam latch or latch pin

– Gouges and/or scrapes in the cam latch or latch pin chrome plating or base material

– Deformations of the cam latch or latch pin

– Any other damage not identified in Inspection Conditions 1 and 2.

(1) Contact Boeing and provide a detailed description of the inspection findings (and

photographs, if possible).

(2) Contact Boeing for additional inspection and/or repair instructions and perform applicable

inspection and/or repair.

8. Put the airplane back to a serviceable condition.

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ALERT ALERT
FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION

(SHEET 1 OF 3)

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ALERT ALERT
FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS 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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Detailed inspection of the

cam latch.(a)

1 Inspect Cam Latch 1 69-23438-2 1

Detailed inspection of the

cam latch.(a) (b)

2 Inspect Cam Latch 2 143N8060-1 1

Detailed inspection of the

cam latch.(a) (b)

3 Inspect Cam Latch 3 143N8027-2 1

Detailed inspection of the

cam latch.(a)

4 Inspect Cam Latch 4 69-23439-3 1

Detailed inspection of the

cam latch.(a)

5 Inspect Cam Latch 5 69-23439-4 1

Detailed inspection of the

cam latch.(a) (b)

6 Inspect Cam Latch 6 143N8027-1 1

Detailed inspection of the

cam latch.(a) (b)

7 Inspect Cam Latch 7 143N8060-2 1

Detailed inspection of the

cam latch.(a)

8 Inspect Cam Latch 8 69-23438-1 1

Detailed inspection of the

latch pin.(a)

9 Inspect Latch Pin 6-83137-2 8

(a) Look for signs of damage, distress or incorrect rigging. Some examples are: broken parts, cracks, deformations, flaking of the chrome plating, wear of the chrome plating down to the base material, corrosion,

chips, gouges etc.

(b) Cam Latches 2, 3, 6 and 7 are not chromed, therefore chrome flaking and chrome wear through cannot

be assessed at these locations. Check for excessive wear.

FIGURE 1: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION

(SHEET 3 OF 3)

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FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE MEASUREMENT

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Torque Bolt NAS6603-24 8 (a)

(a) Make sure the cross bolt is capable of reacting a 15 pound-inch, +/- 1 pound-inch, torque from the head

side of the bolt and also the nut side if no nutplate is used. The 15 pound-inch, +/- 1 pound-inch, torque

value is approximately one-half of the installation torque and is used to give an indication of the integrity

of the cross bolt.

FIGURE 2: MAIN CARGO DOOR - LATCH PIN CROSS BOLT TORQUE MEASUREMENT

(SHEET 2 OF 2)

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FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Make sure the latch

pin extends out 0.90

inch +/- 0.01 inch

from the wear plate.

1 Measure Latch Pin 6-83137-2 8

FIGURE 3: MAIN CARGO DOOR - LATCH PIN EXTENSION MEASUREMENT

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove / Keep Cam Latch 1 69-23438-2 1

2 Remove / Keep Cam Latch 2 143N8060-1 1

Do a HFEC inspection of cam latch 1 for signs

of cracks in accordance with 757 NDT Part

6, 51-00-12 or 51-00-21.(a) (b) (c)

3 Inspect Cam Latch 1 69-23438-2 1

Do a HFEC inspection of cam latch 2 for signs

of cracks in accordance with 757 NDT Part

6, 51-00-12 or 51-00-21.(a) (b) (c)

Inspect Cam Latch 2 143N8060-1 1

4 Install (Kept) Cam Latch 1 69-23438-2 1

5 Install (Kept) Cam Latch 2 143N8060-1 1

(a) Use a 0.080 inch diameter or smaller HFEC probe. Set the HFEC instrument to operate between 50 KHz

and 75 KHz. If HFEC method indicates a crack, confirm a crack using magnetic particle inspection. Refer

to SOPM 20-20-01 as an accepted procedure.

(b) An optional magnetic particle inspection can be used. Refer to SOPM 20-20-01 as an accepted procedure.

(c) HFEC indications can be confirmed using the magnetic particle inspection. If crack indications are found

with HFEC and could not be confirmed with magnetic particle inspection, the HFEC crack indication is a

non relevant indication due to chrome cracking.

FIGURE 4: MAIN CARGO DOOR - CAM LATCH 1 AND CAM LATCH 2 INSPECTION

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

NAS6603-24 (BACB30NF3-22 8 -

optional)

1 Remove Bolt

Install with BMS 3-27 corrosion inhibiting materialBACB30LM3-24 8

(BACB30LM3-22 optional)

2 Install (New) Bolt

FIGURE 5: MAIN CARGO DOOR - LATCH PIN CROSS BOLT REPLACEMENT

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT

(SHEET 1 OF 3)

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ALERT ALERT
FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT

(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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Gusset must be removed to allow removal of cam latch

number 4.

1 Remove Cam Latch - -

2 Install (New) Cam Latch - - (a) (b)

(a) Use the original removed cam latch as a pattern/template to locate new cross bolt holes. Match hole angularity from existing cam latch.

(b) Cam latch number 2 and cam latch number 7 only have two cross bolt holes.

FIGURE 6: MAIN CARGO DOOR - CAM LATCH REPLACEMENT

(SHEET 3 OF 3)

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ALERT ALERT
FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 757-52A0091

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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove Latch Pin 6-83137-2 - -

Install latch pin wet with BMS 3-27

corrosion inhibiting material on

faying surfaces.

2 Install (New) Latch Pin 6-83137-2 -

FIGURE 7: MAIN CARGO DOOR - LATCH PIN REPLACEMENT

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 757-52A0091

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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove Cam Latch - - (a) (b)

Detailed inspection

of the cam latch for

cracks.

2 Inspect Cam Latch - -

3 Install (Kept) Cam Latch - - (a)

(a) It is important to identify the Cam Latch part locations to ensure the parts are re-installed in correct locations.

Cam latches installed incorrectly may seriously compromise proper door operation.

(b) Gusset must be removed to allow removal of cam latch number 4.

FIGURE 8: MAIN CARGO DOOR - CAM LATCH REMOVAL AND INSPECTION

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 9: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

General visual inspection of the cam

latch.(a)

1 Inspect Cam Latch 1 69-23438-2 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 2 143N8060-1 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 3 143N8027-2 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 4 69-23439-3 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 5 69-23439-4 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 6 143N8027-1 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 7 143N8060-2 1

General visual inspection of the cam

latch.(a)

Inspect Cam Latch 8 69-23438-1 1

General visual inspection of the latch

pins.(a)

2 Inspect Latch Pin 6-83137-2 8

(a) Inspect for broken, cracked, missing or migrated parts.

FIGURE 9: MAIN CARGO DOOR - CAM LATCHES AND LATCH PINS INSPECTION

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING

(SHEET 1 OF 3)

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FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING

(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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Measure Cam Latch - - (a) (b)

Measure Latch Pin 6-83137-2 - (a) (b)

Measure Latch Pin Fitting - - (c)

(a) During rigging procedure the latch pin is not to contact the cam latch in any direction.

(b) Wrap a single layer of 0.002 inch thick shim stock around latch pins 1 and 8. Use thin tape to keep shim

in place. With latch pins 1 and 8 engaging their respective cam latches, and with latch pins 2 through 7

not contacting their respective cam latches in any direction, adjust if required, latch pin fittings 2 through

7 such that latch pins 2 through 7 axial centerlines and their respective cam latch axial centerlines are

within the tolerance shown.

(c) Adjust latch pin fittings by moving fitting on serrations and by adjusting shim thickness. On the two forward

and two aft cam latches the Latch Pin Fitting/Cam Latch gap is 0.14 +/- 0.01 inch. On the four center cam

latches the Latch Pin Fitting/Cam Latch gap is 0.08 +/- 0.01 inch. Make sure the maximum allowed shim

thickness of 0.20 inch is not exceeded.

FIGURE 10: MAIN CARGO DOOR - CAM LATCH AND LATCH PIN RIGGING

(SHEET 3 OF 3)

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ALERT ALERT
FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT

(SHEET 1 OF 2)

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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 this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Hold scale 90 degrees to door edge.

Make sure the MCD lower edge and

lower corner flushness are within

the tolerance shown.

1 Measure Main Cargo Door - -

FIGURE 11: MAIN CARGO DOOR - MAIN CARGO DOOR EDGE FLUSHNESS MEASUREMENT

(SHEET 2 OF 2)

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ALERT ALERT