BULLETIN A53-231

FUSELAGE - Main Frame - Inspect/Repair Aft Fuselage Non-Ventral Pressure

Bulkhead Tee.

This page transmits Revision 2 for DC-9 Alert Service Bulletin A53-231 to

incorporate the following changes:

NOTE: This revision constitutes a complete reissue and reflects

current operators of affected aircraft at time of issue.

Reason for Revision:

Page 1:

Pages 6

and 7:

Pages 10

and 11:

Pages 12

14, and

15:

February 24/89

To incorporate engineering released subsequent to prior

issue of this Alert Service Bulletin, which adds a

different eddy current probe for aircraft which have

accomplished Alert Service Bulletin A53-147. A different

eddy current probe is required because an operator could

not inspect aft pressure bulkhead tee using the standard

probe provided by prior issue of this Service Bulletin.

This condition is due to the length of Hi-Lok pins used

to modify aircraft per DC-9 Service Bulletin A53-147.

No additional work is required by this revision for

aircraft previously inspected/repaired by prior issue

of this Alert Service Bulletin.

Changed page number to 1 of 50, was 1 of 46.

Added NOTE under paragraph 1.C., Option II, Condition 2.

Revised Approval statement.

Changed Service Sketch to 3683D, was 3683C.

Added DC-9 Service Bulletin A53-147 to References as new paragraph

1.J.(2). Reidentified subsequent paragraphs accordingly.

Added paragraphs 1.L and 1.M.

Added new GENERAL NOTE 1, reidentified subsequent notes accordingly.

Added new paragraph 2.C, reidentified subsequent paragraphs

accordingly.

Added NOTE under paragraphs 2.A.(4) and 2.K.(4).

Bulletin A53-231

Page 1 of 2

Revision 2 June 25/93
Revised Figure 3 as follows:

Added NOTE under paragraph 8.f.(1) on Sheet 2 of 17.

Added Note under paragraph B.(1)(a) and revised paragraph

(1)(c) under Sequence 1 on Sheet 4 of 17.

Revised paragraph (1)(c) under Sequence 2 on Sheet 5 of 17.

Added new sheet 7, and 15 through 17. Reidentified sheets

accordingly.

Revised callout for eddy current probe on Sheet 6 of 17.

Revised callout for eddy current probe on Sheet 8 of 17.

Revised paragraphs 3.A(1) and 3.A.(3).

Revised paragraphs 3.C.(1) and 3.C.(4).

Revision Seauence:

Original Date

Revision 1

Revision 2

February 24/89

April 2/90

June 25/93

CAS

LL-2

Bulletin A53-231

Page 2

February 24/89

Revision 2 June 25/93

Pages 19

thru 35:

Pages 45

and 46:

Pages 47

and 50:
BULLETIN A53-231

FUSELAGE - Main Frame - Inspect/Repair Aft Fuselage Non-Ventral Pressure

Bulkhead Tee.

QNTE

This Alert Service Bulletin is affected by Federal

Aviation Administration Airworthiness Directive No.

89-06-04: Amendment 39-6152, effective March 24, 1989.

This Alert Service Bulletin is applicable only

to aircraft equipped with the non-ventral aft pressure

bulkhead which have accumulated 25,000 or more landings.

Replacement of all six aft pressure bulkhead tee

sections with new improved parts per this Alert Service

Bulletin constitutes closing action for the repetitive

inspection requirements of this Alert Service Bulletin.

This Alert Service Bulletin supersedes but does not

cancel the requirements of DC-9 Alert Service Bulletin

A53-191. Only aircraft listed in this Alert Service

Bulletin that are contained in the Effectivity of Alert

Service Bulletin A53-191 are affected by this

contingency.

This Alert Service Bulletin is issued as a partial

record-type change. A service rework drawing or

aperture cards are furnished in lieu of illustrations.

1. Planning Information:

A. Effectivitv:

(1) Aircraft Affected:

DC-9. Series 10. 30. and C-9

February 24/89 Bulletin A53-231

Revision 2 June 25/93 Page 1 of 50
(a) Operator and Aircraft Number:

Operator Factory Serial No. Operator Factory Serial No.

AC 45845

47019

47021

47024

47069

47195

47198

47265

47289

47292

47340

47348

47353

47422

47485

47546

47554

47557

47560

47592

47598

47611

BD .45712

45719

45738

47048

C0

GB

and 47022

thru 47071

and

and

and

thru

thru

thru

and

47199

47266

47290

47294

47342

47350

47354

and 45713

and 45739

47423 and

EA 45733

45833

45837

45863

47161

47181

47215

47327

47402

and

and

47424

45734

45834

thru 45865

and 47328

EZ 47220

47355

47414

45728

45874

47040

47074

47147

47165

47269

47384

47403

47413

I1 47408

JP 47392

ML 45835

45838

45866

45869

45876

47140

47157

47166

47186

47214

and 47148

and

thru

and

and

and

45836

45840

45867

47167

47187

NK 47268

NW 45703

45707

45729

45744

45770

45825

45829

47049

47097

47139

47141

47158

47162

47182

47185

47376

thru 45705

and 45708

thru 45749

thru 45832

thru 47145

thru 47164

and 47183

FP 45702

February 24/89 Bulletin A53-231

Revision 2 June 25/93

Page 2
ODerator

RS

TW

US

VC

XYX

YUZ

ZCA

February 24/89

Factory Serial No.

45721 and 45722

45776

45780 and 45781

45783

47125

47127

47082

47095 and 47096

47134 thru 47137

47409

45846

45868

47020

47023

47053 and 47054

47057 and 47058

47066

47068

47188 and 47189

47216

47351 and 47352

45875

47036

47272

47330 and 47331

47399

47401

45696

45711

45718

45725

45727

45795

45842

45720

45714

45736

45743

47043

47059

47085

47122

47126

Operator

ZCP

ZDF

ZGM

ZG4

ZIL

ZJ6

ZK7

ZNV

Z3Z

Z4B

Z5F

Z5X

Z5Y

Z6H

Z7B

Z8H

Factory Serial No.

47151

45871 thru 45873

47270 and 47271

45778

45782

45784

47329

45698 and 45699

47060

45775

45740

47041

47221

47639

45701

45709

45723

45695

47123

47119

45715 and 45716

45735

45737

45741 and 45742

45779

45843 and 45844

47217

45730

45706

Bulletin A53-231

Page 3

Revision 2 June 25/93
(b) Manufacturer's Fuselage and Factory Serial Numbers:

This modification is applicable only to listed aircraft.

(2) Spares Affected:

None.

Bulletin A53-231

Page 4

February 24/89

Revision 2 June 25/93
B. Reason:

One operator reported a cracked aft pressure bulkhead attach tee

section on one aircraft. The aircraft was a non-ventral bulkhead

aircraft. The crack in the upstanding leg of the tee extended

circumferentially approximately 24 inches from the production end

of the tee, at splice between longerons 17 and 18 left side, upward

to longeron 15. The affected aircraft had accumulated 36,079 landings

when the crack was found. Analysis of the failed part revealed that

the crack initiated at multiple sites on the forward surface of the

upstanding leg of the tee as the result of fatigue due primarily to

bending loads. Five other operators reported cracks in a total of

eight other aircraft. These eight aircraft had accumulated between

39,172 and 81,915 landings. The predominant areas of cracks were at

the upper splice between longeron 6 and 7 (4 cases left side); one

crack occurred respectively at longeron 8, 11, 12, 13, and 15

(predominately on left side); and lower pylon attach angle at or

between longeron 16 and 17 (5 cases left side and one case right

side). If cracks are not detected and repaired, they could progress

to the point that rapid decompression could occur. Inspection of high

cycle aircraft and accomplishment of repairs based on condition will

allow continued flight operation.

C. DescriDtion:

This Service Bulletin accomplishes the following on the fuselage aft

pressure bulkhead.

Option I (Inspection from aft side of bulkhead)

Performs visual and low frequency eddy current inspections for cracked

aft pressure bulkhead web-to-fuselage tee sections around the entire

periphery of the fuselage from the aft side of the bulkhead and

accomplishes the following:

Condition 1 (No Crack)

Repetitively visually and low frequency eddy current inspects for

cracks from aft side of bulkhead at intervals specified in Compliance

paragraph.

Condition 2 (Crack)

Replaces cracked tee section with new like or improved part and

repetitively visually and low frequency eddy current inspects for

cracks from aft side of bulkhead at intervals specified in Compliance

paragraph.

February 24/89 Bulletin A53-231

Page 5 Revision 2 June 25/93
Option II (Inspection from forward side of bulkhead)

Performs high and low frequency eddy current inspections for cracked

aft pressure bulkhead web-to-fuselage tee sections around the entire

periphery of the fuselage from the forward side of the bulkhead and

accomplishes the following:

Condition 1 (No crack)

Repetitively high and low frequency eddy current inspects for cracks

from forward side of bulkhead at intervals specified in Compliance

paragraph.

Condition 7 (Crack)

Replaces cracked tee section with new like or improved part and

repetitively high and low frequency eddy current inspects for cracks

from forward side of bulkhead at intervals specified in Compliance

paragraph.

NOTE: Replacement of all six aft pressure

bulkhead tee sections with new

improved parts constitutes closing

action for the repetitive inspection

requirements of this Alert Service

Bulletin.

D. Compliance:

It is recommended that initial inspection/repair of aft pressure

bulkhead tee per Option I or II be accomplished as follows on

aircraft having logged over 25,000 landings.

Accumulated Landinas Initial Inspection

25,000 to 49,999 Within 1500 landings from

issue date of Revision 1

of this Service Bulletin

50,000 to 59,999 Within 1000 landings from

issue date of Revision 1

of this Service Bulletin

60,000 and over Within 300 landings from

issue date of Revision 1

of this Service Bulletin

When aft pressure bulkhead tee section is replaced with new like part,

the repetitive inspection for that section of tee may be discontinued

until the aircraft has accumulated an additional 25,000 landings at

which time the repetitive Inspection for that section of tee are

reinstated along with the ongoing repetitive inspections of the

remaining original sections of tee.

Bulletin A53-231 February 24/89

Page 6 Revision 2 June 25/93
When aft pressure bulkhead tee section Is replaced with new improved

part per this Alert Service Bulletin, the repetitive inspection for that

section of tee may be discontinued as this constitutes closing action

for that section of tee. Perform the recommended Option I or Option

II repetitive inspections on the remaining original tee sections.

Replacement of all six aft pressure bulkhead tee sections with new

Improved parts per this Alert Service Bulletin constitutes closing

action for the inspection requirements of this Alert Service Bulletin.

It is recommended that repetitive inspection/repair of aft pressure

bulkhead tee be accomplished per Option I or II as follows:

Option I (Inspection from aft side of bulkhead)

It is recommended that repetitive low frequency eddy current inspection

for cracks of side areas above floor between longerons L7 and L17 on

fuselage left and right sides, be accomplished at intervals not to

exceed 2000 landings.

It is recommended that repetitive visual inspection for cracks of top

and lower areas from longeron L7 left side to longeron L7 right side,

and lower fuselage longeron L17 to longeron L20 on fuselage left and

right sides, be accomplished at intervals not to exceed 1500 landings.

It is recommended that repetitive visual inspection for cracks of bottom

areas from longeron 120 left side to L20 right side, be accomplished at

intervals not to exceed 3500 landings.

It is recommended that cracked tee section be replaced prior to further

pressurized flight.

Option II (Inspection from forward side of bulkhead)

It is recommended that repetitive high and low frequency eddy current

inspection for cracks around entire periphery of fuselage from forward

side of bulkhead be accomplished at intervals not to exceed 2500

landings.

It is recommended that cracked tee section be replaced prior to further

pressurized flight.

E. Approval:

The resultant modification described in paragraph 1.C has been shown to

comply with the applicable Federal Aviation Regulations and Revision 2

is approved by the Manager, Los Angeles Aircraft Certification Office,

FAA Northwest Mountain Region on June 17, 1993, and is approved as an

alternate means of compliance with paragraphs A, B, and C of

Airworthiness Directive No. 89-06-04.

February 24/89 Bulletin A53-231

Page 7 Revision 2 June 25/93
F. Manpower:

NOTE: Man-hours are estimated based on work to be performed

by skilled personnel on aircraft/unit which has been

placed in a maintenance status. The man-hour/elapsed

time estimates do not include:

1. Preparation for the modification: Examples; defueling,

purging, placing work stands, opening standard access

doors, obtaining tools, and jacking when not essential

to the modification.

2. Nonproductive elapsed time: Examples; sealant or

adhesive cure time, cleaning, paint drying time, lunch

and/or rest periods, and quality assurance inspections.

3. Administrative functions: Examples; planning,

engineering liaison, parts requisition, shift change

coordination, and report writing.

Operators should take the above into consideration when

scheduling this modification.

ODtion I (Inspection from aft side of bulkhead)

Optically aided visual inspection from the aft side of the fuselage aft

pressure bulkhead may be accomplished in approximately 22.0 man-hours or

11.0 elapsed hours per aircraft.

Low frequency eddy current inspection from the aft side of the fuselage

aft pressure bulkhead may be accomplished in approximately 11.5

man-hours or 5.8 elapsed hours per aircraft.

Man-hours do not include time for fabrication of flexible borescope

guide tube.

Option II (Inspection from forward side of bulkhead)

Removal and reinstallation of lavatories, equipment, and sealant for

access to the forward side of the fuselage aft pressure bulkhead tee may

be accomplished in approximately 140.1 man-hours or 52.9 elapsed hours

per aircraft.

High and low frequency eddy current inspection from the forward side of

the fuselage aft pressure bulkhead may be accomplished in approximately

8.0 man-hours or 4.0 elapsed hours per aircraft.

Man-hours do not include time for fabrication of eddy current reference

standard.

Maximum total man-hours and elapsed hours are given for inspection per

aircraft. Actual man-hours and elapsed hours for repair are contingent

upon inspection findings and are to be estimated by the operator.

Bulletin A53-231 February 24/89

Page 8 

Revision 2 June 25/93

Page 8
G. Material - Cost and Availability:

(1) Aircraft:

Parts and materials required to accomplish this modification are

listed in paragraph 3.A and are to be procured as indicated. Parts

bearing Douglas Aircraft Company part numbers are proprietary parts

and must be procured under the spare parts article of the purchase

agreement, unless methods of manufacture are shown.

Cost and availability of parts are to be negotiated between the

operator and Douglas Aircraft Company. Reference this Service

Bulletin number and direct inquiries to:

(2) Spares:

Not applicable.

H. Toolina - Price and Availability:

Option I (Inspection from aft side of bulkhead)

(1) Special test equipment is required to accomplish the low frequency

eddy current inspection per Option I outlined in this Service

Bulletin. Special test equipment is to be procured from operator's

stock, or sources indicated in paragraph 3.C.

(2) Douglas special eddy current reference standard shown in Figure 2

and listed in paragraph 3.C is required to accomplish low frequency

eddy current inspection per Option I and will be made available to

the operator at no charge.

Procurement and availability of SB08530231-9 special eddy current

reference standard should be negotiated between the operator and the

Douglas Aircraft Company. Specify this Service Bulletin number and

direct inquiries to:

Douglas Aircraft Company

910 East 236th Street

Carson, California 92805

Attn: Group Leader - Recovery

and Modification Services 78-22

(DC-9 Alert Service Bulletin A53-231)

February 24/89 Bulletin A53-231

Page 9

Revision 2 June 25/93
Option II (Inspection from forward side of bulkhead)

(3) Test equipment required to accomplish high and low frequency

eddy current inspections per Option II is listed in service sketch

3683D. Choice of test equipment is at operator's option and is to

be procured from operator's stock or sources indicated in service

sketch 3683D.

(4) Reference standard required to accomplish high and low frequency

eddy current inspections per Option II is shown in service sketch

36830. Reference standard may be procured from operator's stock,

fabricated by the operator, or purchased from source indicated in

paragraph 3.D.

I. Weight and Balance:

Weight change at appropriate fuselage stations by incorporation

of any part of this Alert Service Bulletin is contingent upon the

modification of each particular aircraft. Weight data is to be

computed by the operator by weighing parts installed and parts

removed during modification. Necessary revisions should be made

to the appropriate weight and balance document.

3. References:

(1) Federal Aviation Administration Airworthiness Directive

No. 89-06-04: Amendment 39-6152, effective March 24, 1989.

(2) Alert Service Bulletin A53-147.

(3) Data used in preparation of this Alert Service Bulletin:

Data Identification

DMS 2082

3060157

3060157

MM Chapters 6, 20,

21, 25, 26, 36,

49, 52, and 53

NDT Chapter 1-3

SRM Chapters 51 and 53

SR09530001

SR09530001

SR09530048

SR09530056

SR09530056

SR09530083

5910163

5910163

A

B

C

D

New

C

D

New

DF

DG, DH,

and DJ

3683D

Tyoe of Data

Douglas Material Specification

Service Rework Shoring

Advance E.O.

Maintenance Manual

Nondestructive Testing Manual

Structural Repair Manual

Service Rework Drawing

Advance E.O.

Service Rework Drawing

Service Rework Drawing

Advance E.O.

Service Rework Drawing

Drawing

Advance E.O.

Service Sketch (attached)

February 24/89

Bulletin A53-231

Revision 2 June 25/93

Page 10
(4) Data supplied in support of this Alert Service Bulletin:

Data Identification Change Type of Data

J060157 A Service Rework Shoring

J060157 B Advance E.O.

SR09530001 C Service Rework Drawing

SR09530001 D Advance E.O.

SR09530048 New Service Rework Drawing

SR09530056 C Service Rework Drawing

SR09530056 D Advance E.O.

SR09530083 New Service Rework Drawing

NOTE: Listed data are being furnished

to each affected operator.

K. publications Affected:

The modification outlined in this Alert Service Bulletin affects

the DC-9 Weight and Balance Documents.

L. Electrical Load Data:

Not affected.

M. Software Accomplishment Summary:

Not affected.

February 24/89

Revision 2 June 25/93

Bulletin A53-231

Page 11
2. Accomplishment Instructions:

WARNING: TO AVOID INJURY TO MAINTENANCE PERSONNEL

OR DAMAGE TO EQUIPMENT, MAKE CERTAIN

ADEQUATE PRECAUTIONS ARE TAKEN WHILE

- PERFORMING ANY WORK IF ELECTRICAL POWER

IS APPLIED TO THE AIRCRAFT.

CAUTION: ELECTRICALLY GROUND THE AIRCRAFT.

GENERAL NOTES:

1. Replacement of all six aft pressure bulkhead tee sections with

new improved parts constitutes closing action for the repetitive

inspection requirements of this Alert Service Bulletin.

If replacing all six aft pressure bulkhead tee sections, replacement

should be accomplished one tee section at a time.

2. Refer to sections of the Maintenance Manual (MM), Structural Repair

Manual (SRM), and Non-Destructive Testing Manual (NDT).

3. Refer to the following manual chapters for applicable operations:

Manual Chapter Operation

MM 20-30-0 Sealant Application

NDT 1-3 Eddy Current Inspection

SRM 51-10-4 Drilling and Countersinking

SRM 51-30-1 Installing Bolts, Screws, and Washers

SRM 51-30-2 Removing and Installing Rivets

SRM 51-30-3 Removing and Installing Lockbolts

SRM 51-30-5 Removing and Installing Pins

SRM 51-60-0 Substitution and Interchangeability

Option I (Inspection from aft side of bulkhead)

A. Operator's Option - Access doors may be Installed in skin on bottom of

fuselage forward of auxiliary power unit (APU) door per service rework

drawing SR09530048 to facilitate inspection.

B. Operator's Option - Fabricate guide tube (to be used with flexiscope)

from flexible or thin wall tubing to fit outside diameter of flexiscope

as shown on Figure 1.

C. Operator's option - Fabricate reference standard as shown on Figure 2.

D. Gain access to inspection areas on aft side of bulkhead by opening or

removing and retaining the following access doors/panels as applicable

to accomplish visual and/or low frequency eddy current inspection:

Access No. Access Area MM Chapter

5806A Auxiliary Exit Door, 6-12-0

Non-Ventral Bulkhead

5901A Thrust Reverser Control 6-11-4

Valve (Left Side)

February 24/89 Bulletin A53-231

Page 12 Revision 2 June 25/93
Access Area MM Chapter

5902A Thrust Reverser Control 6-11-4

Valve (Right Side)

5903A APU Service (Left Side) 6-11-4

5904A APU Service (Right Side) 6-11-4

NoTE: The following paragraphs 2.D through

2.H may be accomplished at operator's

option and are applicable to visual

inspection requirements.

E. Remove and retain APU and attaching parts. (See MM chapter 49-10-0,

paragraph entitled "Removal/Installation Power Plant.")

F. Remove and retain APU compartment enclosure and attaching parts.

(See MM chapter 53-20-5, paragraph entitled "Removal/Installation

APU Compartment Enclosure.")

G. Remove and retain lower firex bottle and attaching parts. (See

MM chapter 26-20-1, paragraph entitled, "Removal/Installation Fire

Extinguishing Containers.")

H. Remove and retain right pneumatic crossfeed valve pushrod and

attaching parts. (See MM chapter 36-10-3, paragraph entitled

"Removal/Installation Pneumatic Crossfeed Valve.")

I. Remove and retain two upper 5953635 conditioned air duct assemblies,

check valves, and attaching parts aft of pressure bulkhead center

ceiling. (See MM chapter 21-20-2, paragraph entitled

"Removal/Installation Conditioned and Cold Air Check Valve.")

J. Roll back or remove and retain Insulation blankets from aft side of

aft pressure bulkhead. (See MM chapter 25-22-0, paragraph entitled

"Removal/Installation Insulation Blankets.")

K. Perform optically aided visual and low frequency eddy current

inspection/repair of the aft pressure bulkhead web to fuselage skin

attach tee sections from the aft side of the bulkhead as follows:

(1) Inspect the upstanding leg of 5910163 non-ventral bulkhead tee

sections from aft side of bulkhead around the periphery of the

bulkhead as shown on Figure 3 and accomplish the following:

Condition 1 (No Crack)

(2) Perform repetitive visual and/or low frequency eddy current

inspections from aft side of bulkhead at intervals specified

in Compliance paragraph.

Bulletin A53-231 February 24/89 2

Access No.

Revision 2 June 25/93 Page 13
Condition 2 (Crack)

(3) Replace cracked tee section with new like or improved part

per Figure 4 (See Table I for configuration) prior to further

pressurized flight. Perform repetitive visual and/or low

frequency eddy current inspections from aft side of bulkhead

at intervals specified in Compliance paragraph.

(4) If any tee section is to be replaced, remove and retain

engines 1 and 2. (See MM chapter 71-00-0, paragraph

entitled "Removal/Installation Power Plant.")

NOTE: If replacing all six aft pressure

bulkhead tee sections, replacement

should be accomplished one tee

section at a time.

(5) Shore aircraft as shown on Figure 5.

L. Record and report all results negative and positive of inspection to

DAC. Include fuselage number, factory serial number, crack location,

crack length, flight-hours, and accumulated landings of aircraft.

Forward to:

Douglas Aircraft Company

P.O. Box 1771

Long Beach, California 90801

Attn: Manager, Customer Service 76-40

(DC-9 Alert Service Bulletin A53-231)

M. Apply PR-1422 B-2 sealant around entire periphery of the

bulkhead tee sections, as applicable.

N. Reinstall retained insulation blankets on aft side of aft

pressure bulkhead. (See MM chapter 25-22-0, paragraph

entitled, "Removal/Installation Insulation Blankets.")

0. Reinstall right pneumatic crossfeed valve pushrod and attaching

parts as applicable. (See MM chapter 36-10-3, paragraph entitled

"Removal/Installation Pneumatic Crossfeed Valve.")

P. Reinstall two upper 5953635 conditioned air duct assemblies, check

valves, and attaching parts as applicable. (See MM chapter 21-20-2,

paragraph entitled "Removal/Installation Conditioned and Cold Air

Check Valve.")

Q. Reinstall lower firex bottle and attaching parts as applicable.

(See MM chapter 26-20-1, paragraph entitled, "Removal/Installation

Fire Extinguishing Containers.")

R. Reinstall APU compartment enclosure, as applicable. (See MM chapter

53-20-5. paragraph entitled "removal/Installation APU Compartment

Enclosure.")

February 24/89 Bulletin A53-231

Page 14 Revision 2 June 25/93
S. Reinstall APU and attaching parts as applicable. (See MM chapter

49-10-0, paragraph entitled "Removal/Installation Power Plant.")

T. Reinstall engines 1 and 2 as applicable. (See MM chapter 71-00-0,

paragraph entitled "Removal/Installation Power Plant.")

U. Remove shoring as shown on Figure 5 as applicable.

V. Close/reinstall access doors/panels as outlined under Option I

paragraph 2.C.

ODtion II (Inspection from forward side of bulkhead)

A. Perform high and low frequency eddy current inspections of the aft

pressure bulkhead web to fuselage skin attach tee sections from the

forward side of the bulkhead as follows:

(1) Operator's Option - Fabricate eddy current reference standard as

shown on service sketch 3683D, Figure 5.

(2) Remove and retain items as outlined in service sketch 3683D,

Table I, as applicable.

(3) Inspect the standing leg of 5910163 or SB09530056 non-ventral

bulkhead tee sections from forward side of bulkhead around the

entire periphery of the bulkhead as shown on service sketch 3683D,

and accomplish the following:

Condition 1 (No Crack)

Perform repetitive high and low frequency eddy current inspections

from forward side of bulkhead at intervals specified in Compliance

paragraph.

Condition 2 (Crack)

Replace cracked tee section with new like or improved part per

Figure 4 (See Table I for configuration) prior to further

pressurized flight. Perform repetitive high and low frequency

eddy current inspections from forward side of bulkhead at intervals

specified in Compliance paragraph.

(4) If any tee section is to be replaced, remove and retain

engines 1 and 2. (See MM chapter 71-00-0, paragraph entitled

"Removal/Installation Power Plant.") Shore aircraft as shown

on Figure 5.

NOTE: If replacing all six aft pressure

bulkhead tee sections, replacement

should be accomplished one tee

section at a time.

Bulletin A53-231 February 24/89

Revision 2 June 25/93 Page 15
B. Record and report all results negative and positive of inspection to

DAC. Include fuselage number, factory serial number, crack location,

crack length, flight-hours, and accumulated landings of aircraft.

Forward to:

C. Apply PR-1422 B-2 sealant around entire periphery of the bulkhead

tee sections, as applicable.

D. Reinstall engines 1 and 2 as applicable. (See MM chapter 71-00-0,

paragraph entitled "Removal/Installation Power Plant.")

E. Remove shoring as shown on Figure 5 as applicable.

F. Close/reinstall retained items as outlined in service sketch 3683D

Table I, as applicable.

February 24/89 Bulletin A53-231

Revision 2 June 25/93 Page 16
Bulletin A53-2

Page 17

FLEXIBLE BORESCOPE GUIDE TUBE - FABRICATION AND USE

31 FIGURE 1

Rev i

February 24/89

sion 2 June 25/93
EDDY CURRENT REFERENCE STANDARD - FABRICATION

February 24/89 FIGURE 2

Revision 2 June 25/93

Bulletin A53-231

Page 18
Bulletin A53-231

Page 19

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 1 OF 17) February 24/89

Revision 2 June 25/93
February 24/89

Revision 2 June 25/93

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 2 OF 17) Bulletin A53-231

Page 20
*Bulletin A53-231

Page 21

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 3 OF 17) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 3 (SHEET 4 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 22
Bulletin A53-231

Page 23

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 5 OF 17) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 3 (SHEET 6 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 24
Bulletin A53-231

Page 25

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 7 OF 17) February 24/89

Revision 2 June 25/93
February 24/89

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 8 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 26
Bulletin A53-231

Page 27

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 9 OF 17) February 24/89

Revision 2 June 25/93
February 24/89

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 10 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 28
Bulletin A53-231

Page 29

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 11 OF 17) February 24/89

Revision 2 June 25/93
February 24/89

Revision 2 June 25/93

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 12 OF 17) Bulletin A53-231

Page 30
Bulletin A53-231

Page 31

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 13 OF 17) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 3 (SHEET 14 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 32
Bulletin A53-231

Page 33

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 15 OF 17) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 3 (SHEET 16 OF 17)

Revision 2 June 25/93

Bulletin A53-231

Page 34
Bulletin A53-231

Page 35

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 17 OF 17) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 4 (SHEET 1 OF 6)

Revision 2 June 25/93

Bulletin A53-231

Page 36
Bulletin A53-231

Page 37

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 4 (SHEET 2 OF 6) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 4 (SHEET 3 OF 6)

Revision 2 June 25/93

Bulletin A53-231

Page 38
Bulletin A53-231

Page 39

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 4 (SHEET 4 OF 6) February 24/89

Revision 2 June 25/93
AFT PRESSURE BULKHEAD TEE - INSPECTION

February 24/89 FIGURE 4 (SHEET 5 OF 6)

Revision 2 June 25/93

Bulletin A53-231

Page 40
Bulletin A53-231

Page 41

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 4 (SHEET 6 OF 6) February 24/89

Revision 2 June 25/93
SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT

February 24/89 FIGURE 5 (SHEET 1 OF 3) Bulletin A53-231

Revision 2 June 25/93 Page 42
SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT

FIGURE 5 (SHEET 2 OF 3) February 24/8!

Revision 2 June 25/93

e n

Page 43

n
SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT

February 24/89 FIGURE 5 (SHEET 3 OF 3) Bulletin A53-231

Revision 2 June 25/93 Page 44
February 24/89

Revision 2 June 25/93

Bulletin A53-231

Page 45
Bulletin A53-231

Page 46

February 24/89

Revision 2 June 25/93
B. The basis for the followina material data is per spares.

None.

C. The basis for the following toolina data is per operator.

(1) Option I - Test equipment to be procured from operator's

stock or sources indicated.

NOTE: One 70 or 90 degree endoscope of any

diameter with 18 inch minimum length

and matching light source may be used.

Test Equipment Supplier

Endoscope 70 Degree

(Foreoblique) Angle

19 (304.8 MM)-Inch Long

0.217 (5.51 MM)-Inch

Diameter

or

Equivalent

Fiber Optic

Light Bundle

and

Endoscope Light Source

110 or 220 Volt

and

Sylvania Projector Lamp

150 Watt, 120 Volt

Model

103200

Model

1F8D3

1 54341 Expanded Optics,

Incorporated

301-C West Dyer Road

Santa Ana, California

92702-3427

1

No. 00482

or

No. E0590

1

QNTE: Similar or equivalent endoscopes

and illuminators may be obtained

from the following sources.

Bulletin A53-231

February 24/89

Page 47

Revision 2 June 25/93
Bulletin A53-231

Page 48

February 24/89

Revision 2 June 25/93
TIY Otv AE Supplier

Eddy Current Low

Frequency Molded

Probe 5-50 kHz

Operating Frequency

Model 1

C/N 935-0120

P/N APB/MSP

(Zetec Incorporated)

or

Eddy Current Low

Frequency Molded

Probe 5-50 kHz

Operating Frequency

Model

SP0-4080

(Staveley Instruments

Incorporated)

Eddy Current Low

Frequency 90 Degree

Probe 5-50 kHz

Operating Frequency

Model 1

C/N 910-5830

P/N APB/90DP

(Zetec Incorporated)

or

Eddy Current Low

Frequency 90 Degree

Probe 5-50 kHz

Operating Frequency

or

Eddy Current Low

Frequency 90 Degree

Probe 5-50 kHz

Operating Frequency

Model

SPO-4081

(Staveley Instruments

Incorporated)

Model

SP0-5222

NOTE: When ordering Eddy Current probes specify

type of Eddy Current instrument the probe

will be used with so that proper mating

connectors or adapter will be provided.

(2) Option I - One SB09530231-9 Eddy Current Reference Standard required

to accomplish Option I low frequency eddy current inspection will be

made available at no charge. (See paragraph 1.H.)

(3) Option II - Test equipment required to accomplish Option II high

and low frequency eddy current inspections including procurement

sources, is listed in service sketch 3683D. Choice of equipment

is at operator's option and is to be procured from operator's

stock or sources indicated in service sketch 3683D.

February 24/89 Bulletin A53-231

Revision 2 June 25/93 Page 49

Test Equipment
(4) Option II - The following reference standard required to accomplish

the Option II high and low frequency eddy current inspections Is to

be procured from operator's stock or as indicated.

InstructionsPart No. Qtv Kev Word Disposition

MS20470AD5-6 2 Rivet 2/ 2/

MS20470AD5-7 4 Rivet Z/ I/

SB09530231-11 1 Plate I/ 4/

SB09530231-13 1 Web I/ 5/

SB09530231-15 1 Tee 1/ 6/

SB09530231-17 1 Reference 1/

Standard Assy

1/ May be purchased from: VM Products Incorporated E

11298 62nd Avenue 60761

Puyallup, Washington 98373

or

May be fabricated by the operator. (See service sketch 3683D.)

2/ May be procured from operator's stock.

2/ Detail of SB09530231-17 reference standard assembly.

4/ May be fabricated by the operator from 7075-T6 clad aluminum

sheet Material Specification QQ-A-250/13 Temper T6 or 7075-T6

bare aluminum plate Material Specification QQ-A-250/12 Temper

T6, .047/.053 x 2-1/4 x 3 Inches. (See service sketch 3683D.)

5/ May be fabricated by the operator from 7075-T6 clad aluminum

sheet Material Specification QQ-A-250/13 Temper T6 or 7075-T6

bare aluminum plate Material Specification QQ-A-250/12 Temper

T6, .039/.045 x 2-1/4 x 4-1/2 Inches. (See service sketch

36830.)

I/ May be fabricated by the operator from 2024-T3 clad aluminum

sheet Material Specification QQ-A-250/5 Temper T3 or 2024-T4

bare aluminum plate Material Specification QQ-A-250/4 Temper

T4, .075/.085 x 3 x 4-1/2 Inches. (See service sketch 3683D.)

Any Inquiries regarding accuracy, timeliness, completeness, and

legibility of this Alert Service Bulletin should be directed to

the local DAC Field Representative, or:

Douglas Aircraft Company

P.O. Box 1771

Long Beach, California 90801

Attn: Business Unit Manager

Service Bulletins

Service Changes and Modification Kits

Product Support 76-40

(DC-9 Alert Service Bulletin A53-231)

ENW/CAS

G3H/LL

Bulletin A53-231 February 24/89

Revision 2 June 25/93 Page 50
INSPECTION PROCEDURE

1. GENERAL NOTES:

(1) This procedure describes high and low frequency Eddy Current

inspection of DC-9 aft pressure bulkhead tee sections to detect

fatigue cracks in standing leg of tee sections.

(2) Inspection

for cracks

bulkhead.

of either ventral or nonventral bulkhead tee sections

is made from the forward side of the aft pressure

(See Figures 1 and 2.)

2. TEST EqUIPMENT:

A. Eddy Current Equipment:

(1) Eddy Current CRT Instruments:

Nortec NDT-15, NTD-18, or NDT-19

or

Zetec EM3300, or EM4300

or

Hocking Aeromaster G,

AVIOB or AV100
or

Hocking Electronics Limited

St. Albans, Hertfordshire

England

Equivalent

NOTE: Eddy current Instruments

with meters are not acceptable

for this Inspection.

(2) High Frequency Eddy Current Probes. (See Figure 4.)

Shielded pencil/surface (90' angle) operating at about 200 kHz,

0.125-Inch maximum diameter.

Model MP901-60B 90' Angle NDT Products Engineering

or 7056 South 220 Street

Model MP901-60FX 90' Angle Kent, Washington 98032

or

Model 1R90F-6-1/16 J

or

CAGE: 61100

GK Engineering Corporation

21610 Lassen Street Suite 1

Chatsworth, California

91311-4121

CAGE: 58136

Equivalent.

N0TE: When ordering Eddy Current

probes specify type of Eddy

Current Instrument the probe

will be used with so that

proper mating connectors or

adapter will be provided.

(3) Low Frequency Eddy Current Probe. (See Figure 4.)

Right angle, 1/2-inch drop, surface probe operating at 1-40 kHz.

Model SPO 1071 Staveley Instruments

Incorporated

421 North Quay Street

Kennewick, Washington 99336-7735

or CAGE: 29192

Equivalent

(4) Eddy Current Reference Standard - Local Manufacture. (See Figure 5.)

N0TE: May be purchased from: VM Products Incorporated

11298 62nd Avenue

Puyallup, Washington 98373

CAGE: 60761
3. ACCESS PREPARATION FOR INSPECTION:

a. Gain access to work area by removing and retaining items outlined in

Table I, as applicable. Access below the FRP is through cargo

compartment access panels. (See Figure 3.)

b. Remove and retain, or loosen wire bundles, ducting, hydraulic lines, and

attaching parts, as required.

c. Remove sealant from inspection area and clean with lint-free wiper and

1,1,1 trichloroethane solvent or equivalent.

TABLE I

REMOVE AND RETAIN

MM CHAPTER

REFERENCE PARAGRAPH TITLE

AFT LAVATORY EQUIPMENT, TOILET

WASTE TANKS, WASTE PLUMBING

AND LAVATORY(IES), PARTITIONS

AND/OR AFT GALLEY(IES), AND

ATTACHING PARTS AS APPLICABLE

IMMEDIATELY FORWARD OF AFT

PRESSURE BULKHEAD.

CARPETING AND FLOOR PANELS,

LAVATORY FLOOR PANS AND/OR

GALLEY FLOOR PANELS, AND

ATTACHING PARTS AS APPLICABLE,

IMMEDIATELY FORWARD OF AFT

PRESSURE BULKHEAD.

25-30-0

THRU

25-41-0

REMOVALS/INSTALLATION

(AS APPLICABLE.)

38-30-1

AND/OR

53-20-3

25-20-0

AND/OR

53-20-7

GENERAL, AND REMOVAL/INSTALLATION

GALLEY FLOOR COVERING.

INSULATION BLANKETS AND

ATTACHING PARTS ON FORWARD

SIDE OF AFT PRESSURE BULKHEAD

AS NECESSARY TO GAIN ACCESS

TO INSPECTION AREA.

THRUST REVERSER CONTROL VALVE

SECTOR AND BRACKET.

APPLICABLE TO DC-9 SERIES

MD-80 AIRCRAFT ONLY - CABIN

AIR RECIRCULATION FAN.

25-22-0

AND

25-52-1

78-31-2

REMOVAL/INSTALLATION INSULATION

BLANKETS AND REMOVAL/INSTALLATION

SIDEWALL, CEILING, AND FLOOR

PANELS.

REMOVAL/INSTALLATION THRUST

REVERSER CONTROL VALVE SECTOR.

21-20-13 REMOVAL/INSTALLATION CABIN AIR

RECIRCULATION FAN.
4. HIGH FREQUENCY PROCEDURE:

NOTE: High frequency procedure is applicable to Eddy

Current inspection in area of tee sections not

covered by the bulkhead web.

A. Connect high frequency Eddy Current probe and set frequency at

approximately 200 kilohertz. Place probe on reference standard and

balance instrument per manufacturer's instructions. (See Figure 6.)

B. Set sensitivity and phase controls to obtain CRT response from notch 5.

Without changing sensitivity, scan notches 5 and 6 and observe CRT

presentation of crack. (See Figures 6 and 7.)

C. Place probe on tee and slowly scan surface toward and away from the vertex

of tee angle. Do not adjust balance, phase, or sensitivity controls.

With the exception of tee splice plate areas, progressively scan entire

360 degrees of tee sections forward perimeter. (See Figure 8.)

NOTE: One technician is to operate the probe

while another technician evaluates the Eddy

Current response on the CRT. Technician

watching CRT should periodically erase the

lift-off traces from the scope to avoid

missing a small crack indication as shown

in Figure 9 views (a) and (b). Technician

watching scope must continually talk to

technician operating probe to indicate if

probe is making good contact with metal

surface as illustrated in View (c).

D. Any indication which exhibits same relative phase angle and an amplitude

equal to or greater than 50 percent of CRT presentation obtained from

calibration notch 6 in the reference standard is considered a crack.

E. Measure length of each crack and distance between multiple cracks.

Report all crack indications to DAC as noted.

5. LOW FREQUENCY PROCEDURE:

NOTE: Low frequency procedure is applicable

to Eddy Current inspection of tee

sections covered by the bulkhead web.

F. Connect low frequency Eddy Current probe and set frequency at

approximately five kilohertz. Place probe on reference standard at

probe position A and scan notches 2 and 4 and observe CRT presentation

of crack. (See Figure 10.)

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET

3683D OF NO. 19
G. Set sensitivity and phase controls to obtain CRT response from notches 2

and 4 as shown on Figure 11 (a).

H. Without changing sensitivity place probe on web and scan around each

fastener in the splice plate area paying particular attention to area

near edge of web. Progressively scan entire 360 degrees of tee sections

splice plate areas forward perimeter. (See Figure 12.)

NOTE: One technician is to operate the probe

while another technician evaluates the Eddy

Current response on the CRT. Technician

watching CRT should periodically erase the

lift-off traces from the scope to avoid

missing a small crack indication as shown in

Figure 9, Views (a) and (b). Technician

watching scope must continually talk to

technician operating probe to indicate if

probe is making good contact with metal

surface as illustrated in View (c).

I. Recalibrate instrument at two kilohertz with probe at position B on

reference standard. Scan across notches 1 and 3. Set sensitivity and

phase controls to obtain CRT response from notches 1 and 3 as shown on

Figure 11 (b). Without changing sensitivity, place probe on tee splice

plate area and scan around fasteners paying particular attention to area

near edge of splice plate. (See Figure 12.)

J. Any indication which exhibits the same relative phase angle and an

amplitude equal to or greater than 50 percent of CRT presentation

obtained from the half thickness notches 3 and 4 in reference standard

is considered a crack. Cracks may be confirmed by checking the aft side

of the tee using the high frequency procedure in paragraphs A through

E. Cracks which do not break through to the aft surface of the tee may

be checked using this low frequency procedure of paragraphs F through K.

K. Measure length of each crack and distance between multiple cracks.

Report all crack indications to DAC as noted.

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 5

3683D OF 19 NO.
DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 6

NO. 3683D OF 19
FIGURE 2. DC-9 NON-VENTRAL AFT PRESSURE BULKHEAD.

TYPICAL FOR VENTRAL AFT PRESSURE BULKHEAD.

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 7

NO. 3683D OF 19
ACCESS PANEL LOCATION

AFT END OF CARGO

COMPARTMENT

(LOOKING AFT)

FIGURE 3.

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH

NO. 3683D

SHEET 8

OF 19
GK ENGINEERING 1R90F-6-1/16J

FIGURE 4. EDDY CURRENT PROBES

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 9

NO. 3683D OF 19
DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 10

NO. 3683D OF 19
DETAIL SB09530231-15 TEE

FABRICATE FROM 2024-T3 CLAD ALUMINUM SHEET

MATERIAL SPECIFICATION QQ-A-250/5 TEMPER T3

OR 2024-T4 BARE ALUMINUM PLATE MATERIAL

SPECIFICATION QQ-A-250/4 TEMPER T4,

.075/.085 X 3 X 4-1/2 INCHES

HIGH AND LOW FREQUENCY EDDY CURRENT

REFERENCE STANDARD - FABRICATION

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH

NO. 3683D

SHEET 11

OF 19

FIGURE 5.
DETAIL SB09530231-11 PLATE

FABRICATE FROM 7075-T6 CLAD ALUMINUM SHEET

MATERIAL SPECIFICATION QQ-A-250/13 TEMPER T6

OR 7075-T6 BARE ALUMINUM PLATE MATERIAL

SPECIFICATION QQ-A-250/12 TEMPER T6

.047/.053 X 2-1/4 X 3 INCHES

HIGH AND LOW FREQUENCY EDDY CURRENT

REFERENCE STANDARD - FABRICATION (CONT)

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH

NO. 3683D

SHEET 12

OF 19

FIGURE 5.
REFERENCE STANDARD MAY BE PURCHASED FROM:

VM PRODUCTS INCORPORATED

11029 POLK STREET EAST

P. O. BOX 44926

TACOMA, WASHINGTON 98444

CAGE: 60761

FIGURE 5. - HIGH AD LOW FREQUENCY EDDY CURRENT

REFERENCE STANDARD - FABRICATION (CONT)

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 13

3683D OF 19 NO.
FIGURE 7. SCOPE PRESENTATION

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 14

NO. 3683D OF 19
FIGURE 8. EDDY CURRENT CHECK OF BULKHEAD TEE (360° ) FROM FORWARD SIDE

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 15

NO. 3683D OF 19
FIGURE 9. CRT PRESENTATIONS USING PROBE

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 16

NO. 3683D OF 19
FIGURE 10. LOW FREQUENCY CALIBRATION PROCEDURE USING NOTCHES 1 THROUGH 4

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH

NO. 3683D

SHEET 17

OF 19
DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 18

NO. 3683D OF 19
FIGURE 12. LOW FREQUENCY EDDY CURRENT CHECK OF BULKHEAD TEE (360°)

THROUGH WEB AND SPLICE PLATES

DC-9 S/B A53-191, A53-231,

REF: AND A53-232

SERVICE SKETCH SHEET 19

3683D OF 19 NO.