MDC-92K9145 

Revision E 

REVlSED 'UVISION 

LETTER 

~------ ------------~llim ~E=X~O~F~P~A~G~E~C~H~A~N~G~E~S------~------~----~ PAGES AFFECTED REMARKS 

New 

A 

B 

c 

D 

E 

REVISED ADDEO DELETED 

1-3 

1.4 

Title Page 

Title Page 

I- 4 

1- 5,18 

Title Page 

Title Page 

Dl 

All Initial release. 

4 

5 

3 

6 - 15 

App. B & 

c 

Add item #2. 

Add item #3. 

Removed revision record. 

Added 717 appucability. 

Added/re-numbered Items #3, #4, #5. 

Clarified intent of SCI's versus CMR's. 

Moved items 1 - 5 to appendix A. 

Separated item #I into SC!s 27-1 thru 27-

4; renumbered item #2 into SCI 35-1; 

renumbered item #3 into SCI 35-2; 

renumbered item #4 into SCT 35-3; 

renumbered item #5 into SC124-l. 

Revised title and added revision record. 

Revised title page signatures as a result of 

SF AR88 activities. Added revision letter 

to each page in report. 

Added CDCCL's and ALl's in 

Appendices B and C, respectively, as a 

result ofSFAR88 activity. 

Revised page number and applicability in 

Appendix D to include ALl's as well as 

SCI's. Revised word ing on short-term 

extensions in Appendix D. 

Due to content and timing issues regarding FAA approval of revision E and F of 

this report, tbe content of these two 

revisions have been swapped; previous 

revision F is now revision E, and previous 

revision E will in the future be revision F. 

Both previous revisions have been 

rescinded by Boeing. 

BOEING PROPRI ETARY IN FORMATION 

Copyright © - The Boeing Company- Unpublished Work 

APPROVED 

BY BY 

M. 3/1 8/ 1994 

McKelvey 

D. Olsen I 0/3 1/ 1994 

D. Olsen 9/26/ 1995 

G. Nixon 6/ 1/200 I 

J. Bouey 11 /5/2004 

M. 12/15/2005 

McKelvey ~ 

\-vll':i/o·J" 

Page i 
I 

REVISION 

LETTER 

f 

INDEX OF PAGE CHANGES 

PAGES AFFECTED REMARKS 

REVISED ADDED DELETED 

82 

8 22,824 

822-823 

823 

824 

827 

833 

C6-C7 

II 

C8-C9 

AJO 

Added addhional lndex of Change Pages, 

to accommodate changed information for 

revision f. 

Deleted SCI 27-4 for the 717 horizontal 

stabilizer primary trim relay, as the SCI 

was incorrectly generated for a failure 

mode which was designed out for the 

717. 

Revised CDCCL implementation intent 

from an Operator's maintenance program 

to their control documents. This ensures 

that an Operator's Engineering department has visibility of control limitation 

information. 

Lear-Romec PIN RRI 2559A was de leted, 

as it is a fuel pump sub-assembly, rather 

than the end item PIN RR 12551 A. 

Added Nash fuel pump volute PIN's 

previously and inadvertently omitted. 

Revised Argo-Tech fue l pump CMM 

revision level; this latest revision includes 

speci tic SF AR88 warnings. 

Revised Lear-Romec fuel pump CMM 

revision level to reflect the current 

released version. 

Revised DC-9 Indicator CMM revision 

level; this latest revision includes specific 

SF AR88 warnings. 

Revised CDCCL 28-7 to provide an 

acceptable, alternate means of ensuring 

the fue l ptunp connector is properly 

torqued. 

Revised ALl 20-2 to delete the MD-90 

model, which uses a different wiring 

design. 

Added ALI 20-3 for the MD-90 configuration, reflecting a different wiring design 

than in ALI 20-2. 

BOEING PllOPRIETARY INFORMATION 

Copyright © - The Boeing Company- Unpublished Work 

MDC-92K9145 

Revision f 

REVISED 

BY 

M. 

McKelvey 

APPROVED 

BY 

8/9/2006 

Page ii 
REVISION 

LETTER 

G 

MDC-92K9145 

Revision G 

INDEX OF PAGE CHANGES 

PAGES AFFECTED 

REVISED ADDED DELETED 

A2 

A4-A9 

Bl9 

B22-B24, 

B33 

B27 

iii 

REMARKS REVISED 

BY 

Added additional Index of Change Pages, M. 

to accommodate changed information for McKelvey 

revision F. 

SCI reference to short-term extensions 

was appendix B; it should have been 

appendix D. 

Revised SCis 27-1, 27-2 and 27-3 to 

change "remove and replace" with 

"remove, then replace with OEM 

overhauled or new", thus eliminating the 

potential for refurbishment per CMM. 

Added alternate PIN of same relay. 

Replaced incorrect AMM references with 

correct AMM references; moved 

inspection interval rationale to SCI 

interval question 8 in SCI 27-3. 

Revised CDCCL 20-11 to change the 

word "right" to "either", as some twinjets 

have an auxiliary hydraulic pump in the 

left wheelwell. 

Revised CDCCL 28-2 for Argo-Tech fuel 

pump CMM 28-20-6 to revision 6 and 

added new pump assembly PIN 398000-2 

to both CDCCLs 28-2 and 28-7, 

reflecting a SF AR88 design change (lead 

wire shield) and reliability enhancement 

(gold plated connector pins). 

Revised Goodrich I Simmonds I Liquidomter fuel quantity master indicator 

CMMs 28-40-14 and 28-41-41 to 

revision 4, as it was inadver-tently not 

revised in the previous revision to this 

SCI; revision 4 includes specific SF AR88 

warnings. 

APPROVED 

BY 

6/7/2007 

~~--------~------~------L-------~------------------------~------~------~ 

BOEING PROPRfET AR Y INFORMATION 

Copyright ©- The Boeing Company- Unpublished Work 

Page iii 
MDC-92K9145 

Revision L 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page iv

INDEX OF PAGE CHANGES 

REVISION PAGES AFFECTED 

LETTER REVISE

D 

ADDED DELETED 

REMARKS REVISED 

BY 

APPROVED 

BY 

H 

I 

J 

vi-vii 

A12 

A14 

A14-A15 

B2 

B22-B34 

B30 

vi-viii 

iv 

A13 

B21 

v 

Added additional Index of Page Changes, 

to accommodate changed information for 

revision H. 

Revised Table of Contents to add 

CDCCL 20-13 and increment page 

numbers for following CDCCLs. 

Revised SCI 35-2 to remove incorrect 

AMM 35-20-00 reference and insert 

correct AMM task references. Revised 

interval from 12 years to 15 years. 

Revised SCI 35-3 to remove incorrect 

AMM 35-10-00 reference and insert 

correct AMM task references; also 

changed the words “generator canisters” 

in paragraph 5 to “oxygen cylinder”. 

All pages have been incremented to 

accommodate inclusion of revised SCI 

35-2. 

Revised second to last paragraph to 

clarify CDCCL configuration control 

information to applicable Operator’s 

Maintenance documentation. 

Added CDCCL 20-13 for float and 

pressure switch circuit fuse sleeves, part 

of BDCO Project LB07-0018. 

All pages have been incremented to 

accommodate inclusion of new CDCCL 

20-13. 

Revised CMM Revision Levels for CMM 

28-40-34 from Rev 5 to Rev 7 and 28-40-

58 Rev 12 to Rev 15. 

Revision I is not used 

Added additional Index of Page Changes, 

to accommodate changed information for 

revision H. 

Revised pages to accommodate new 

Index of Page Changes Page and updated 

page numbers to accommodate new page. 

M. Cox 

M.Cox 

1/18/2008 

M. McKelvey 
REVISION 

LETTER 

J 

K 

INDEX OF PAGE CHANGES 

PAGES AFFECTED REMARKS 

REVISED ADDED DELETED 

vi, Al4 

Al5 

B21 B22 

B22-B35 

B25 

B29 

B31 

B33 

v ix 

ix 

B4 

BlO 

B13 

Added CFR 26.33 Statement 

Revised SCI 35-3 inspection interval 

from 3 years to 5 years to match DOT 

standards. 

Revised SCI 24-1 to include alternate 

method of determining life 

Added the fuse to CDCCL 20-13 and 717 

applicability 

Incremented pages to accommodate new 

page 

CDCCL 28-2 revised CMM Revision 

Levels for CMM 28-20-1 from Rev 5 to 

Rev 6, CMM 28-20-2 Rev 2 to Rev 3 and 

CMM 28-20-03 Rev 5 to Rev 6. 

CDCCL 28-4 revised CMM Revision 

Levels for CMM 28-40-14 from Rev 4 to 

Rev 5. 

CDCCL 28-5 revised CMM Revision 

Levels for CMM 28-40-53 from Rev 8 to 

Rev 10. 

CDCCL 28-6 revised CMM Revision 

Levels for CMM 28-40-93 from Rev 2 to 

Rev 4 and 28-40-99 Rev IR to Rev 2 

Revised IOPC added new IOPC, 

incremented pages table of contents 

Revised table of contents to add new 

CDCCL and new ALis 

CDCCL 20-1 was revised the limitations 

section to replace with same gauge. 

CDCCL 20-5 limitations was revised to 

allow use of the SWPM 

CDCCL 20-8 characteristics and 

limitations section re-written to further 

clarify the design intent and to allow 

additional documents that are allowed in 

the limitation 

BOEING PROPRIETARY INFORMATION 

Copyright©- The Boeing Company- Unpublished Work 

MDC-92K9145 

Revision J 

REVISED 

BY 

APPROVED 

BY 

J. Van Dalen 

I 'I...--. '{C. 

H. Don 

It 1 A' I 

A. Macias 

J..tt,, 

2/Z/10 

M. McKelvey 

A~'~ 9 "l;tJ/Jo 

T. Harris 

-{3&) 

B. Nozari 

!lt~r 

Pagev 
REVISION 

LETTER 

K 

L 

M 

INDEX OF PAGE CHANGES 

PAGES AFFECTED REMARKS 

REVISED ADDED DELETED 

B17-B19 

B21-B22 

B31 

B33 

ix 

vi-ix 

B31 

B33 

C4-C5 

B36, 

C10-Cll 

C1 2-C15 

X 

A16-A19 

CDCCL 20-10 and CDCCL 20-11 

limitations was revised to allow more 

documents that can maintain the 

limitation 

CDCCL 20-13, added applicability 

statement. 

CDCCL 28-5 Revised CMM Rev level 

from 15 to 16 for CMM 28-40-58 

CDCCL 28-6 Revised CMM Rev level 

from 2 to 3 for CMM 28-40-99 

Added Ground Fault Indicator CDCCL 

28-8 and Associated ALI test 28-1 

ALI 28-2 was added to check 

uncommanded running circuit. 

Revised Table of Contents to remove 

CDCCL 28-8, ALI 28-1 and ALI 28-2 

B36, C10- Removed Ground Fault Indicator CDCCL 

C 11 28-8 and Associated ALI test 28-1 , 

C12-C15 Removed ALI 28-2 to check 

uncommanded running circuit. 

Revised IOPC, added new sheet. Causing 

the table of contents to move a page. 

Revised table of contents to add SCI 34-

1, CDCCL 28-8, ALI 28-1 28-2, and 

revise the name of ALI 20-1 

Added SCI 34- 1 Functional Test of the 

Captain and First Officers Altimeter 

Revised CDCCL 28-5 to reflect CMM 

28-40-53 revised to Rl2 from RIO. 

Revised CDCCL 28-5 to reflect CMM 

28-40-93 revised to R5 from R4 

Revised ALI 20-1 re-titled and revised to 

include all circuit protection devices for 

fue~ pumps and aux hydraulic pumps 

from just circuit breakers. 

BOEING PROPRIETARY INFORMATION 

Copyright ©- The Boeing Company- Unpublished Work 

MDC-92K9145 

Revision M I 

REVISED 

BY 

M.Cox 

APPROVED 

BY 

See Previous 

Page 

Page vi 
REVISION 

LETTER 

M 

N 

INDEX OF PAGE CHANGES 

PAGES AFFECTED REMARKS 

REVISED ADDED 

B36, 

Cl0-Cl2 

Cl3-Cl5 

I, Vll 

Vll- IX 

A20-A75 

DELETED 

Added Ground Fault Indicator CDCCL 

28-8 and Associated ALI test 28-1 

ALI 28-2 was added to check 

uncommanded running circuit. 

Revised Title page and Index of Page 

Changes 

Updated Table of Contents to include SCI 

26- 1 through 26-4. 

Incorporated SCI 26- 1 through 26-4 Fire 

Detection System Integrity Check. 

BOEING PROPRIETARY INFORMATION 

Copyright©- The Boeing Company- Unpublished Work 

MDC-92K9145 

Revision N 

REVISED APPROVED 

BY BY 

~ 7V(fi/?fi 

Page vii 

~ 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page viii

TWINJET SPECIAL COMPLIANCE ITEMS REPORT

TABLE OF CONTENTS

PAGE No. TITLE INTERVAL SUMMARY

 At intervals, prior to, 

 but not to exceed: 

1 Discussion 

A1 Appendix A - SCIs 

A4 27-1 DC-9 Replace Primary Longitudinal 8,000 flt hrs 

Up/Down Contactors 

A6 27-2 MD-80 Replace Primary Longitudinal 16,000 flt hrs 

Up/Down Contactors 

A8 27-3 MD-90 Replace Primary Longitudinal 16,000 flt hrs 

Up/Down Contactors 

A10 Blank Page 

A11 35-1 MD-80/MD-90 Replace Scott Aviation 12 years 

Passenger Chemical Oxygen Generators 

A12 35-2 717 Replace Drager Passenger 15 years 

Chemical Oxygen Generators 

A14 35-3 717 Replace Flight Deck Composite 5 years (inspect/retest) 

Oxygen Cylinder 15 years (replacement) 

A15 24-1 DC-9/MD-80 Replace Emergency 3 years 

Power Switch 

A16 34-1 Functional Test of the Captains and 48 months 

 First Officer’s Altimeter 

A20 26-1 DC-9 Fire Detection System Integrity 27 Months 

 Check 

A31 26-2 MD-80 Fire Detection System Integrity 27 Months 

 Check 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page ix

TWINJET SPECIAL COMPLIANCE ITEMS REPORT

TABLE OF CONTENTS

PAGE No. TITLE _______________________

A31 26-3 MD-90 Fire Detection System Integrity 27 Months 

 Check 

A31 26-4 717 Fire Detection System Integrity 27 Months 

 Check

B1 Appendix B - CDCCLs 

B4 20-1 Twinjet Repair Wire Gauges 

B5 20-2 Twinjet FQIS Wire Isolation 

B6 20-3 Twinjet In-Tank Wire Splices 

B8 20-4 Twinjet Repair Wire Types 

B10 20-5 Twinjet Wire Installations 

B11 20-6 Twinjet Prohibition of Power Feeder Splices in Areas Above Fuel Tanks 

B12 20-7 717 Float Switch Conduit Sleeves 

B13 20-8 Twinjet Fuel Tank Access Door Bonding 

B15 20-9 717/MD-80/MD-90 Wing Root Area Lightning Protection 

B17 20-10 Twinjet Fuel Tank Structural Design 

B19 20-11 DC-9 Auxiliary Hydraulic Pump Conduit 

B20 20-12 Twinjet Wiring Near Fuel Tanks and Fuel Pipes 

B21 20-13 DC-9/MD-80/MD-90/717 Float and Pressure Switch Circuit Fuse 

Sleeves 

B23 28-1 Twinjet Prohibit Safety Wire, Lockwire, Safety Cable or Cotter Pins 

Inside Fuel Tanks 

B24 28-2 Twinjet Fuel Pump (Boost or Transfer) and Housing Assemblies 

B27 28-3 Twinjet Fuel Pump Electrical Connector Wire/Conduit Assembly 

N 
MDC-92K9145 

Revision M 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page x

TWINJET SPECIAL COMPLIANCE ITEMS REPORT

TABLE OF CONTENTS

PAGE No. TITLE _______________________

 Appendix B – CDCCLs (cont’d) 

B29 28-4 DC-9 Fuel Quantity Master Indicators 

B31 28-5 MD-80/MD-90 Fuel Quantity Standard Electronic Module 

B33 28-6 MD-80/MD-90/717 Fuel Quantity Standard Electronic Module 

B35 28-7 Twinjet Fuel Pump Connector 

B36 28-8 Twinjet Ground Fault Interrupter 

PAGE No. TITLE INTERVAL SUMMARY

 At intervals, prior to, 

 but not to exceed: 

C1 Appendix C - ALIs 

C4 20-1 Twinjet Fuel Pump and Auxiliary On condition 

 Hydraulic Pump Circuit Protection 

 Devices Reset 

C6 20-2 MD-80 Auxiliary Hydraulic 5,000 flt hrs (effective 

 Pump Power Feeder Wiring 8/2/2006) 

C8 20-3 MD-90 Auxiliary Hydraulic Pump 5,000 flt hrs (effective 

 Power Feeder Wiring 8/2/2006) 

C10 28-1 Twinjet Ground Fault Interrupter Test 4,000 flt hrs 

 

C13 28-2 Twinjet Auxiliary and Center Wing Tank 4,000 flt hrs 

 Fuel Pump Low Pressure Indication Sys 

 Test 

D1 Appendix D - Short Term Extensions 

M 

M 

M 
MDC-92K9145 

Revision J 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page 1

DISCUSSION 

Certain systems in the twinjet fleet (see below) have been analyzed and found to require fixedinterval checks or limitations, as follows: 

 Special Compliance Items (SCIs) - see Appendix A for their description and a listing of 

SCI’s 

 Critical Design Configuration Control Limitations (CDCCLs) - see Appendix B for their 

description and a listing of CDCCL’s resulting from SFAR88 activities 

 Airworthiness Limitation Instructions (ALIs) - see Appendix C for their description and a 

listing of ALIs resulting from SFAR88 activities 

This Special Compliance Items (SCI) Report is the Type Certificate Data Sheet (TCDS) 

referenced report, which contains and documents SCIs, CDCCLs and ALIs. 

14 CFR Part 26.33 Airworthiness Limitations

Applicable airplanes have been analyzed and found to meet the flammability requirements 

without any limitations. 

DC-9 Series

DC-9-11 DC-9-12 DC-9-13 DC-9-14 DC-9-15 DC-9-15F 

DC-9-21 DC-9-31 DC-9-32 DC-9-32 (VC-9C) DC-9-32F 

DC-9-32F (C-9A, C-9B) DC-9-33F DC-9-34 DC-9-34F DC-9-41 

DC-9-51 

MD-80 Series

DC-9-81 DC-9-82 DC-9-83 DC-9-87 MD-88 

MD-90 Series

MD-90-30 

717 Series

717-200 

J 
MDC-92K9145 

Revision D 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A1

Appendix A 

Special Compliance Items (SCIs) 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A2

TWINJET SPECIAL COMPLIANCE ITEM REPORT 

Special Compliance Items (SCIs) are a means of notifying the FAA, operators, and others of 

critical design items that cannot be changed without violating the design intent, potentially 

making the airplane unsafe. For example, the SCI might require a repetitive check of pitot probe 

drains; similarly, the SCI might require a remove and replace task for emergency power 

switches. 

Certification Maintenance Requirements (CMR’s) are used to limit the latency (exposure time) 

for certain safety-significant failures which directly impact Top Event numerical probabilities 

found in fault tree analysis; these can be found in MDC-J1271. 

The terms of the applicable twinjet Type Certificate are only valid when the SCIs are performed 

within the time intervals specified. SCIs are equivalent to one-star CMR’s, per Advisory 

Circular (AC) 25-19: the tasks and intervals specified are mandatory and cannot be changed, 

escalated, or deleted without the approval of FAA Engineering within the Aircraft Certification 

Office having cognizance over the type design. 

Temporary deviations from the SCI intervals are permitted within the limitations of Appendix D. 

While each SCI is included in this report, it is required that each SCI also be included in an 

appropriate document where it will be visible to airline personnel; therefore each SCI must be 

included in each Operator's Maintenance Program. 

The SCIs herein are in addition to the maintenance requirements established by the Maintenance 

Review Board activity and documented in the Maintenance Review Board Report. Inclusion of 

SCIs herein is only intended to limit the extension of task intervals for those portions of twinjet 

systems identified. 
MDC-92K9145 

Revision D 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A3

Each SCI specified herein includes the name of the system in which the SCI is needed, and the 

following information: 

1. What twinjet model does this SCI apply to? 

2. What part or LRU is being checked? 

3. What failure mode is being looked for? 

4. How is it found? 

5. What tasks are to be performed? 

6. Is test equipment needed? 

7. What is the pass-fail criteria? 

8. What is the SCI interval? 

Each Pass-Fail criteria entry identifies each SCI task as an Inspection or Check, using the MRB 

definitions. 

Please report any negative inspection results to your local Boeing Field Service Representative. 

If the Boeing Field Service Representative is not available, you may send the report to: 

The Boeing Company 

3855 Lakewood Blvd. 

Long Beach, CA, USA 90846 

Attn: 

Manager - Avionics & Electrical Systems (Dept. L33) 

Service Engineering 

Technical Services & Modifications 

Mail Code: D800-0035 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A4

SCI 27-1 - DC-9 Replace Primary Longitudinal Up/Down Contactors 

1. What twinjet model does this SCI apply to? 

DC-9 Series 

2. What part or LRU is being checked? 

Primary longitudinal up/down contactors are being replaced or overhauled by OEM, not 

checked nor refurbished using CMM. The part is Leach P/N 5D0355-1 or 9207-10296. 

3. What failure mode is being looked for? 

The contactors are being replaced prior to their anticipated wear-out. 

4. How is it found? 

Remove the primary longitudinal up/down contactors per 5. below, then replace with 

OEM overhauled or new. 

5. What tasks are to be performed? 

Remove the primary longitudinal up/down contactors per Airplane Maintenance Manual 

(AMM) section 27-40-4 Page 401, and then replace with OEM overhauled or new. 

Note: Airworthiness Directive (AD) 91-21-07, titled "Inspection/Replacement of the 

Primary Longitudinal Trim Relays (Up and Down) Leach" mandates removal 

and replacement of these relays (Leach P/N 5D0355-1 or 9207-10296). 

The following references have been used to formulate the recalculation of this 

removal and replacement period: 

1. DAC AVI "DC-9/MD-80 Existing Airworthiness Directives Applicable 

to the MD-90", revision A, dated 11/17/92 

2. DAC AVI C1-ECR-JMS-071 "MD-80 Comparison to DC-9 Flight 

Hours and Application to the Trim Relay Hard Time", dated 12/21/90 

3. DAC AVI C1-ECR-JMS-023-Rev. A "Reliability Analysis of Trim 

Relay Hard-time", dated 12/19/90 

6. Is test equipment needed? 

None. 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A5

SCI 27-1 - DC-9 Replace Primary Longitudinal Up/Down Contactors 

(cont’d) 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of “remove and replace with OEM 

overhauled or new” tasks. 

 

8. What is the SCI interval? 

Remove and replace with OEM overhauled or new at intervals prior to, but not to exceed, 

8,000 flight hours. 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A6

SCI 27-2 - MD-80 Replace Primary Longitudinal Up/Down Contactors 

1. What twinjet model does this SCI apply to? 

MD-80 Series 

2. What part or LRU is being checked? 

Primary longitudinal up/down contactors are being replaced or overhauled by OEM, not 

checked nor refurbished using CMM. The part is Leach P/N 5D0355-1 or 9207-10296. 

3. What failure mode is being looked for? 

The contactors are being replaced prior to their anticipated wear-out. 

4. How is it found? 

Remove the primary longitudinal up/down contactors per 5. below, then replace with 

OEM overhauled or new. 

5. What tasks are to be performed? 

Remove the primary longitudinal up/down contactors per Airplane Maintenance Manual 

(AMM) section 27-40-04 Page 403, and then replace with OEM overhauled or new 

Note: Airworthiness Directive (AD) 91-21-07, titled "Inspection/Replacement of the 

Primary Longitudinal Trim Relays (Up and Down) Leach" mandates removal 

and replacement of these relays (Leach P/N 5D0355-1 or 9207-10296). 

The following references have been used to formulate the recalculation of this 

removal and replacement period: 

1. DAC AVI "DC-9/MD-80 Existing Airworthiness Directives Applicable 

to the MD-90", revision A, dated 11/17/92 

2. DAC AVI C1-ECR-JMS-071 "MD-80 Comparison to DC-9 Flight 

Hours and Application to the Trim Relay Hard Time", dated 12/21/90 

3. DAC AVI C1-ECR-JMS-023-Rev. A "Reliability Analysis of Trim 

Relay Hard-time", dated 12/19/90 

6. Is test equipment needed? 

None. 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A7

SCI 27-2 - MD-80 Replace Primary Longitudinal Up/Down Contactors 

(cont’d) 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of “remove and replace with OEM 

overhauled or new” tasks. 

8. What is the SCI interval? 

Remove and replace with OEM overhauled or new at intervals prior to, but not to exceed, 

16,000 flight hours. 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A8

SCI 27-3 - MD-90 Replace Primary Longitudinal Up/Down Contactors 

1. What twinjet model does this SCI apply to? 

MD-90 Series 

2. What part or LRU is being checked? 

Primary longitudinal up/down contactors are being replaced or overhauled by OEM, not 

checked nor refurbished using CMM. The part is Leach P/N 5D0355-1 or 9207-10296. 

3. What failure mode is being looked for? 

The contactors are being replaced prior to their anticipated wear-out. 

4. How is it found? 

Remove the primary longitudinal up/down contactors per 5. below, then replace with 

OEM overhauled or new. 

5. What tasks are to be performed? 

Remove the primary longitudinal up/down contactors per Airplane Maintenance Manual 

(AMM) section 27-41-03 Page 401, and then replace with OEM overhauled or new. 

6. Is test equipment needed? 

None. 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of “remove and replace with OEM 

overhauled or new” tasks. 
MDC-92K9145 

Revision G 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A9

SCI 27-3 - MD-90 Replace Primary Longitudinal Up/Down Contactors 

(cont’d) 

8. What is the SCI interval? 

Remove and replace with OEM overhauled or new at intervals prior to, but not to exceed, 

16,000 flight hours. 

Note: For the MD-90 series airplanes, these same relays are used in the same manner 

and environment as used for the DC-9 and MD-80 series airplanes; the only 

variable of concern when recalculating the removal and replacement time is 

average flight time, since the time in the cruise flight phase is the only variable 

that significantly changes. Service experience has shown that the MD-80 series 

airplanes average flight time is  1.45 hours; the average flight time for the MD90 series airplanes is estimated to be  1.50 hours. Therefore, expected usage of 

the relay has slightly increased, by 1.50/1.45, or  1.03. 

Since the slight increase in exposure time for relay failure occurs during the 

cruise phase of flight, where primary trim is used less, relay usage for the MD-90 

series airplanes will not significantly change from the MD-80 series airplanes; the 

associated removal and replacement interval will also not significantly change 

from the MD-80 series airplanes to the MD-90 series airplanes. 
MDC-92K9145 

Revision F 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

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SCI 35-1 – MD-80/MD-90 Replace Scott Aviation Passenger Chemical Oxygen Generators 

1. What twinjet model does this SCI apply to? 

MD-80 Series 

MD-90 Series 

2. What part or LRU is being checked? 

Passenger chemical oxygen generators are being replaced, not checked. The part is Scott 

Aviation P/N 801386-( ). 

3. What failure mode is being looked for? 

The oxygen generators are being replaced prior to their anticipated life-limit. 

4. How is it found? 

Remove and replace the passenger chemical oxygen generators per 5. below. 

5. What tasks are to be performed? 

Remove and replace the passenger chemical oxygen generators per Airplane 

Maintenance Manual (AMM) 35-20-00. 

Note: The performance of the passenger chemical oxygen generator, originally 

installed in the MD-80, was evaluated over a period of 12 years to a Douglas 

supervised test program. The generators continued to perform to the test 

criteria during the entire time. 

6. Is test equipment needed? 

None. 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of remove and replace tasks. 

8. What is the SCI interval? 

Remove and replace at intervals prior to, but not to exceed, 12 years. 
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SCI 35-2 – 717 Replace Drager Passenger Chemical Oxygen Generators 

1. What twinjet model does this SCI apply to? 

717 Series 

2. What part or LRU is being checked? 

Passenger chemical oxygen generators are being replaced, not checked. The parts are 

Drager Aerospace P/N’s E74020-00, E74030-00 and E74040-01. 

3. What failure mode is being looked for? 

The oxygen generators are being replaced prior to their anticipated life-limit. 

4. How is it found? 

Remove and replace the passenger chemical oxygen generators per 5. below. 

5. What tasks are to be performed? 

Remove the passenger chemical oxygen generators per the following Airplane 

Maintenance Manual (AMM) Tasks: 

 Task 35-21-01-000-801 (Passenger Service Units) 

 Task 35-21-01-000-802 (Forward Flight Attendant) 

 Task 35-21-01-000-803 (Lavatory) 

 Task 35-21-01-000-804 (Aft Flight Attendant) 

Install replacement passenger chemical oxygen generators per the following AMM 

Tasks: 

 Task 35-21-01-400-801 (Passenger Service Units) 

 Task 35-21-01-400-802 (Forward Flight Attendant) 

 Task 35-21-01-400-803 (Lavatory) 

 Task 35-21-01-400-804 (Aft Flight Attendant) 

Note: The Drager oxygen generators have successfully passed the oxygen flow 

performance test after being subjected, during the qualification test, to 

equivalent aircraft vibration level (reference Drager Aerospace report FPSUGEN-SDRL-05.08). The Drager passenger chemical oxygen generators have 

established a maximum life of 15 years. 

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SCI 35-2 – 717 Replace Drager Passenger Chemical Oxygen Generators 

(cont’d)

6. Is test equipment needed? 

None. 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of remove and replace tasks. 

8. What is the SCI interval? 

Remove and replace at intervals prior to, but not to exceed, 15 years. H 
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SCI 35-3 – 717 Replace Flight Deck Composite Oxygen Cylinder 

1. What twinjet model does this SCI apply to? 

717 Series 

2. What part or LRU is being checked? 

Flight deck composite oxygen cylinder 

3. What failure mode is being looked for? 

Composite oxygen cylinder integrity and capacity 

4. How is it found? 

Re-inspect and retest the composite oxygen cylinder per 5. below. 

5. What tasks are to be performed? 

Re-inspect and hydrostatically retest the composite oxygen cylinder every 5 years in 

accordance with 49 CFR-173.34(E) as prescribed for DOT 3HT cylinders. 

Remove the oxygen cylinder per Airplane Maintenance Manual (AMM) Task 35-11-01-

000-802. Install replacement oxygen cylinder per AMM Task 35-11-01-400-802. 

Note: The B/E Aerospace composite oxygen cylinder is approved for use per 

specification DOT-E8162-1850. The maximum life of the composite oxygen 

cylinder is 15 years. 

6. Is test equipment needed? 

Hydrostatic test equipment, per 49 CFR-173.34(E) as prescribed for DOT 3HT cylinders. 

7. What is pass/fail criteria? 

Successful re-inspection and retest of the cylinder, up to its maximum life of 15 years. 

8. What is the SCI interval? 

Inspect and retest at intervals prior to, but not to exceed, 5 years. 

Remove and replace at intervals prior to, but not to exceed, 15 years. 

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SCI 24-1 – DC-9/MD-80 Replace Emergency Power Switch 

1. What twinjet model does this SCI apply to? 

DC-9 Series 

MD-80 Series 

2. What part or LRU is being checked? 

Emergency power switch, P/N 103-2200 

3. What failure mode is being looked for? 

Replacement of the emergency power switch prior to its anticipated wear-out. 

4. How is it found? 

Remove and replace the emergency power switch per 5. below. 

5. What tasks are to be performed? 

Remove and replace the emergency power switch per Airplane Maintenance Manual 

(AMM) 24-23-02 

6. Is test equipment needed? 

None. 

7. What is pass/fail criteria? 

There is no pass/fail criteria. This SCI consists of remove and replace tasks. 

8. What is the SCI interval? 

Remove and replace at intervals prior to, but not to exceed, 3 years or 10,000 off-to-onto-off cycles. 

Cycles are determined by the following procedure (AD AMOC): 

1. Determine average flight cycles per day for the airframe 

2. Determine switch cycles per day 

3. Determine Airline Factor (AF) by dividing flights per day by switch cycles per 

day 

4. Multiply Airline Factor (AF) by 10,000 to determine flight cycles between switch 

replacements. 

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SCI 34-1 – FUNCTIONAL TEST OF THE CAPTAIN AND FIRST OFFICER’S 

ALTIMETER 

1. What model does this SCI apply to?

MD-80 series, MD-90 series, 717 series that are approved for flying in Reduced Vertical 

Separation Minimum (RVSM) airspace. 

2. What part or LRU is being checked?

MD-80, MD-90: Air Data Computer 

717: Air Data Module 

3. What failure mode is being looked for?

The failure mode tested is transducer degradation of the air data system, which can cause 

erroneous altitude indication. 

4. How is it found?

 Perform inspection per 5 below. 

5. What tasks are to be performed?

 FUNCTIONAL TEST OF THE CAPTAIN’S AND FIRST OFFICER’S ALTIMETER

1. Job Set-up: 

a. Open the circuit breakers referenced in the following AMM procedures: 

i. MD-90: LEAK TEST OF THE PITOT/STATIC SYSTEM (3,000 FEET) 

TASK 34-11-00-790-805 and install safety tags. 

ii. 717: LEAK TEST OF A PITOT SYSTEM TASK 34-11-00-790-808. 

iii. MD-80: Task Adjustment/Test Pitot Static System, 34-11-00 (Page Block 

200). 

b. Apply aircraft electrical power: 

i. MD-90: APPLY EXTERNAL POWER, TASK 24-40-00-861-801. 

ii. 717: APPLY EXTERNAL POWER, TASK 24-40-00-861-801. 

iii. MD-80: EXTERNAL POWER – DESCRIPTION AND OPERATION 24-40-

00 (P/B 001). 

c. Connect the test equipment as follows: 

i. 717 ONLY: 

1. On the ICE PROTECTION panel, make sure that the AIR DATA HEAT 

switch light is off. 

2. Put a DO NOT OPERATE tag, STD-858 on the AIR DATA HEAT 

switch light. 

3. Ensure that Captain’s and First Officer’s PFD are on. 

4. Ensure that the Captain’s and First Officer’s CADC switch light is off. 

ii. MD-80 and MD-90 ONLY: On the overhead panel, place the CADC switch to 

NORM. On the captain’s and first officer’s gusset panels, place the STATIC 

AIR switches to NORM. 

iii. On the ATC control panel, put the mode select knob to the STBY position. 

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SCI 34-1 – FUNCTIONAL TEST OF THE CAPTAIN AND FIRST OFFICER’S 

ALTIMETER (cont’d) 

WARNING: USE ONLY RED POLYESTER TAPE TO SEAL STATIC 

PORTS. IF THE HOLES BECOME CLOGGED WITH TAPE 

RESIDUE, INCORRECT AIRSPEED-SENSING AND 

ALTITUDE-SENSING SIGNALS CAN OCCUR. THIS CAN 

CAUSE DANGEROUS FLIGHT CONDITIONS. 

iv. Seal the captain’s and first officer’s pitot tube drain holes with red polyester 

tape or other suitable device. 

v. Connect the air data tester to the captain’s and first officer’s pitot tube. 

vi. Connect the air data tester to the captain’s and first officer’s static ports using 

suitable adapter. 

vii. Seal the opposite side static ports using red polyester tape or other suitable 

device. 

d. Set the Captain’s and First Officer’s BARO set to 29.92 in/Hg (1013.21 mBar). 

WARNING: MAKE SURE ALL PERSONS AND EQUIPMENT ARE CLEAR 

OF THE AREAS AROUND THE CONTROL SURFACES. THE 

TEST CAN CAUSE THE AIRCRAFT CONTROL SURFACES TO 

MOVE. SUDDEN MOVEMENT OF THE CONTROL SURFACES 

CAN CAUSE INJURY TO PERSONS AND DAMAGE TO 

EQUIPMENT. 

CAUTION: MAKE SURE THE AIR DATA TESTER OPERATES 

CORRECTLY. IF IT DOES NOT OPERATE CORRECTLY, IT 

CAN CAUSE DAMAGE TO THE INSTRUMENTATION 

SENSOR DEVICES. 

CAUTION: WHEN YOU CHANGE ALTITUDE, DO NOT LET THE RATE 

OF CHANGE BE MORE THAN 6,000 FEET PER MINUTE. 

WHEN YOU CHANGE AIRSPEED, DO NOT LET THE RATE OF 

CHANGE BE MORE THAN 100 KNOTS PER MINUTE. DO NOT 

SUDDENLY RELEASE PRESSURE TO THE ATMOSPHERE 

FROM THE PITOT/STATIC LINES WHILE THE AIR DATA 

TESTER IS CONNECTED. DO NOT LET THE STATIC 

PRESSURE BE MORE THAN THE PITOT PRESSURE. THIS 

WILL HELP PREVENT DAMAGE TO THE EQUIPMENT. 

2. Do the functional test of the Captain’s and First Officer’s Altimeter as follows: 

a. On the air data tester, adjust the altitude to 41,000 feet (12,497 m). 

b. On the air data tester, adjust the airspeed to 105 knots. 

c. On the captain’s instrument panel: 

i. Captain’s altitude requirements, the altitude shown on the captain’s altimeter 

must be 41,000 feet (12,497 meters) ± 75 feet (23 meters). 

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SCI 34-1 – FUNCTIONAL TEST OF THE CAPTAIN AND FIRST OFFICER’S 

ALTIMETER (cont’d)

ii. Captain’s airspeed requirements, the airspeed shown on the captain’s airspeed 

indication must be 105 knots ± 4 knots. 

d. On the first officer’s instrument panel: 

i. First Officer’s altitude requirements, the altitude shown on the First Officer’s 

altimeter must be 41,000 feet (12,497 meters) ± 75 feet (23 meters). 

ii. First Officer’s airspeed requirements, the airspeed shown on the First 

Officer’s airspeed indication must be 105 knots ± 4 knots. 

e. On the air data tester, slowly return the pitot and static pressure to the 

atmospheric pressure. 

3. Job Close-up: 

a. Remove the test equipment as follows: 

i. Disconnect the air data tester from the captain’s pitot tube and captain’s static 

port. 

ii. Remove tape from the captain’s pitot tube drain holes and static port. 

b. Remove all the tools and equipment from the work area. Make sure the area is 

clean. 

c. Remove the safety tags and close these circuit breakers opened in Job Set-up. 

d. Remove external power from the aircraft. 

i. MD-90: REMOVE EXTERNAL POWER, TASK 24-40-00-862-801. 

ii. 717: REMOVE EXTERNAL POWER, TASK 24-40-00-862-801. 

iii. MD-80: EXTERNAL POWER – DESCRIPTION AND OPERATION 24-40-

00 (P/B 001). 

6. Is test equipment needed?

 Tester, Air Data: must have a maximum altitude tolerance of +/-15ft (5 m) at 

41,000ft (12,497 m). 

 Adapter, Static Port 

 Adapter, Pitot Head 

 Tape - Polyester, Red, Silicone Adhesive: Specification DPM 850-24 or 

equivalent. 

7. What is pass/fail criteria? 

 

 Pass: 

o Captain’s altitude requirements, the altitude shown on the captain’s altimeter 

must be 41,000 feet (12,497 meters) ± 75 feet (23 meters) at 41,000 feet 

(12,497 meters). 

o Captain’s airspeed requirements, the airspeed shown on the captain’s airspeed 

indication must be 105 knots ± 4 knots at 105 knots. 

o First Officer’s altitude requirements, the altitude shown on the First Officer’s 

altimeter must be 41,000 feet (12,497 meters) ± 75 feet (23 meters) at 41,000 

feet (12,497 meters). 

o First Officer’s airspeed requirements, the airspeed shown on the First 

Officer’s airspeed indication must be 105 knots ± 4 knots at 105 knots. 

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SCI 34-1 – FUNCTIONAL TEST OF THE CAPTAIN AND FIRST OFFICER’S 

ALTIMETER (cont’d) 

 Fail: 

o If any of the altitude and airspeed requirements are outside the tolerances 

listed in the pass criteria. 

8. What is SCI interval?

Intervals not to exceed 48 months.

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

1. What model does this SCI apply to?

DC-9 

2. What part or LRU is being checked?

Fire Detector Wire Routing 

3. What failure mode is being looked for?

This SCI test is to determine if fire detector wiring were crossed as a result of prior 

maintenance activities. 

4. How is it found?

Perform inspection per 5 below. 

5. What tasks are to be performed?

B.  Fire Detector Wire Routing Test

(1)  Place three loop selector switches, located on aft overhead switch panel, in BOTH

position.  

(2)  Make sure that these circuit breakers are closed:

       LOWER EPC, DC TRANSFER BUS

          Number        Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

       OVERHEAD BATTERY BUS

Number        Name  

B1‐291          APU CONTROL

       Left Engine

(3)  Perform fire detector wire routing test for left engine Loop A.

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(4)  Disconnect connector at either end of LOOP A element ‐ located at bottom of

engine,  

(5)  Place jumper wire between ground and center conductor of detector element. Left

engine LOOP A  

Light, FIRE DETECTOR LOOP light on the Annunciator Panel shall come on.

(6)  Open these circuit breakers:

       LOWER EPC, DC TRANSFER BUS

Number       Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

       OVERHEAD BATTERY BUS

Number        Name  

B1‐291          APU CONTROL

(a)   Left Engine LOOP A light ONLY should remain on.

(7)  Close these circuit breakers:

       LOWER EPC, DC TRANSFER BUS

Number        Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191         FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

       OVERHEAD BATTERY BUS

Number        Name  

B1‐291          APU CONTROL  

(8)  Remove jumper wire. Left Engine Loop A light shall go out.

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(9)  Place jumper wire between ground and center conductor of plug that was on

detector. Left Engine LOOP A light, FIRE DETECTOR LOOP light on the Annunciator Panel

shall come back on.

(10) Remove jumper wire Left Engine LOOP A light, FIRE DETECTOR LOOP light on the

Annunciator Panel shall go off.

(11)  Perform fire detector wire routing test for Left Engine Loop B.

(12)  Disconnect connector at either end of LOOP B element located at bottom of

engine.

(13)  Place jumper wire between ground and center conductor of detector element. Left

engine LOOP B light, FIRE DETECTOR LOOP light on the Annunciator Panel shall come on.

(14)  Open these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number        Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

        OVERHEAD BATTERY BUS

       Number           Name  

B1‐291          APU CONTROL

(a)   Left Engine LOOP B light ONLY should remain on.

(15)  Close these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191         FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

         

OVERHEAD BATTERY BUS

Number        Name  

B1‐291          APU CONTROL  

(16)  Remove jumper wire. Left Engine Loop B light shall go out.

(17)  Place jumper wire between ground and center conductor of plug that was on

detector. LOOP B light for left engine Loop B shall come back on.

(18) Remove jumper wire. Loop light shall go off.

(19) Place jumper wire between ground and center conductor of LOOP A detector

element. With LOOP A and B elements grounded, verify the following.

Left Engine Loop A and Loop B lights come on

Fire Detector Loop light on the Annunciator Panel comes on

Left Engine Fire Handle comes on

Fire Aural Warning is heard

(20) Remove jumper wires. Warnings shall stop.  

(21) Restore systems to normal.

         RIGHT ENGINE

(22)  Make sure that these circuit breakers are closed:

         LOWER EPC, DC TRANSFER BUS

Number        Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

         OVERHEAD BATTERY BUS

Number        Name  

B1‐291          APU CONTROL

(23)  Perform fire detector wire routing test for right engine Loop A.

(24)  Disconnect connector at either end of LOOP A element ‐ located at bottom of

engine,  

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(25)  Place jumper wire between ground and center conductor of detector element.

Right engine LOOP a light, FIRE DETECTOR LOOP light on the Annunciator Panel shall

come on.

(26)  Open these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(a)   Right Engine Loop A light ONLY should remain on.

(27)  Close these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐191         FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL  

(28)  Remove jumper wire. Right Engine Loop A light shall go out.

(29)  Place jumper wire between ground and center conductor of plug that was on

detector. Right Engine LOOP A light, FIRE DETECTOR LOOP light on the Annunciator shall

come back on.

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(30) Remove jumper wire. Right Engine LOOP A light, FIRE DETECTOR LOOP light on the

Annunciator Panel shall go off.

(31)  Perform fire detector wire routing test for right engine Loop B.

(32)  Disconnect connector at either end of LOOP B element located at bottom of

engine.

(33)  Place jumper wire between ground and center conductor of detector element.

Right engine LOOP B light, FIRE DETECTOR LOOP light on the Annunciator Panel shall

come on.

(34)  Open these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

       OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(a)   Right engine Loop B light ONLY should remain on.

(35)  Close these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

         OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL  

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(36)  Remove jumper wire. Right Engine Loop B light shall go out.

(37)  Place jumper wire between ground and center conductor of plug that was on

detector. Right Engine LOOP B , FIRE DETECTOR LOOP light on the Annunciator Panel

shall come back on.

(38) Remove jumper wire. Right Engine LOOP B light, FIRE DETECTOR LOOP light on the

Annunciator Panel shall go off.

(39) Place jumper wire between ground and center conductor of LOOP A detector

element. With LOOP A and B elements grounded, verify the following.

Right Engine Loop A and Loop B lights come on

Fire Detector Loop light on the Annunciator Panel comes on

Right Engine Fire Handle comes on

Fire Aural Warning is heard

(40) Remove jumper wires. Warnings shall stop.  

(41) Restore systems to normal.

(42) APU

(43) Place APU Master Switch in RUN position.

  

(44)  Make sure that these circuit breakers are closed:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

        OVERHEAD BATTERY BUS

       Number           Name  

B1‐291          APU CONTROL

(45)  Perform fire detector wire routing test for APU Loop A.

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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(46)  Disconnect connector at either end of LOOP A element ‐ located on fwd side of APU

enclosure inside either APU access door.

(47)  Place jumper wire between ground and center conductor of detector element. APU

LOOP A light, FIRE DETECTOR LOOP light on the Annunciator Panel shall come on.

(48)  Open these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(a)   APU Loop A light ONLY should remain on.

(49)  Close these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐324          FIRE DETECTORS APU LOOP B

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191         FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B  

B1‐280          FIRE WARNING BELL

         OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL  

(50)  Remove jumper wire. APU Loop A light shall go out.

(51)  Place jumper wire between ground and center conductor of plug that was on

detector. APU LOOP A light, FIRE DETECTOR LOOP light on the Annunciator shall come

back on.  

N 
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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(52) Remove jumper wire. APU Loop A light, FIRE DETECTOR LOOP light on the

Annunciator Panel shall go off.

(53)  Perform fire detector wire routing test for APU Loop B .

(54)  Disconnect connector at either end of APU LOOP B element ‐ located on fwd side of

APU enclosure inside either APU access door.

(55)  Place jumper wire between ground and center conductor of detector element. APU

LOOP B light, FIRE DETECTOR LOOP light on the Annunciator Panel shall come on.

(56)  Open these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191          FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(a)   APU Loop B Loop light ONLY should remain on.

(57)  Close these circuit breakers:

         LOWER EPC, DC TRANSFER BUS

Number           Name  

B1‐405          APU FIRE WARNING HORN

B1‐323          FIRE DETECTORS APU LOOP A  

B1‐59            FIRE DETECTORS RIGHT ENGINE LOOP A  

B1‐191         FIRE DETECTORS RIGHT ENGINE LOOP B  

B1‐282          FIRE DETECTORS LEFT ENGINE LOOP A  

B1‐281          FIRE DETECTORS LEFT ENGINE LOOP B

B1‐280          FIRE WARNING BELL

B1‐192          FIRE WARNING LIGHTS

         OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL  

(58)  Remove jumper wire. APU Loop B light shall go out.

N 
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SCI 26-1– DC-9 Fire Detection System Integrity Check 

(59)  Place jumper wire between ground and center conductor of plug that was on

detector. APU LOOP B light, FIRE DETECTOR LOOP light on the Annunciator Panel shall

come back on.

(60) Remove jumper wire. APU Loop B light, FIRE DETECTOR LOOP light on the

Annunciator Panel shall go off.

(61) Place jumper wire between ground and center conductor of LOOP A detector

element. With LOOP A and B elements grounded, verify the following.

APU Loop A and Loop B lights come on

Fire Detector Loop light on the Annunciator Panel comes on

APU FIRE light on the Annunciator Panel comes on

Master Warning light comes on

APU Fire Aural Warning

APU Fire Warning Horn is heard

(62) Remove jumper wires.  

APU Loop A and Loop B lights go off.

Fire Detector Loop light on the Annunciator Panel goes off.

APU FIRE light on the Annunciator Panel goes off.

Master Warning light goes off.

APU Fire Aural Warning goes off.

APU Fire Warning Horn goes off.

  

(63) Restore systems to normal.

(64) Place APU Master Switch to the OFF position.

(65) Open this circuit breaker:

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(66) Operate both Loop A and Loop B test switches at the same time.  

Left Engine, Right Engine and APU Loop A and Loop B lights turn on

APU Fire warning light goes on

Master Warning lights go on

Fire aural warning is heard

Left and Right Engine Fire Handle lights go on

  

Remove the safety tag and close this circuit breaker:

        OVERHEAD BATTERY BUS

Number           Name  

B1‐291          APU CONTROL

(67) Restore systems to normal.

N 
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SCI 26-1– DC-9 Fire Detection System Integrity Check 

6. Is test equipment needed?

Note: When more than one tool part number is listed under the same “Reference” 

number, the tools shown are alternates to each other within the same airplane 

series. Tool part numbers that are replaces or non-procurable are proceeded by 

“Opt:” which stands for Optional. 

Reference Description 

 None Required 

7. What is pass/fail criteria?

Pass: 

During this procedure the fire aural warning and engine fire warning lights (in the 

Firex handle) should not come on and the annunciator fire detector loop light will 

light whenever a LOOP light on the overhead panel is on. The light in the fire 

handle associated with the engine being tested should come on during the 

individual FIRE TEST. 

8. What is SCI interval?

The fire detection integrity test shall be performed at intervals not to exceed 27 months. N 
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SCI 26-2 – MD-80 Fire Detection System Integrity Check 

1. What model does this SCI apply to?

MD-80 

2. What part or LRU is being checked?

Fire Detector Wire Routing 

3. What failure mode is being looked for?

This SCI test is to determine if fire detector wiring were crossed as a result of prior 

maintenance activities. 

4. How is it found?

Perform inspection per 5 below. 

5. What tasks are to be performed?

B. Fire Detector Wire Routing Test 

(1) Place three loop selector switches, located on aft overhead switch panel, in 

BOTH position. 

(2) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP 

A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP 

B 

 W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP 

A 

 W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 

N 
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SCI 26-2 – MD-80 Fire Detection System Integrity Check 

OVERHEAD BATTERY BUS 

 Row Col Number Name 

 B 21 B1-291 APU CONTROL 

 Left Engine 

(3) Perform fire detector wire routing test for left engine Loop A. 

(4) Disconnect connector at either end of LOOP A element - located at bottom of 

engine. 

(5) Place jumper wire between ground and center conductor of detector element. 

Left engine LOOP A Light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come on. 

(6) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

 Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

 W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

 Row Col Number Name 

 B 21 B1-291 APU CONTROL 

 (a) Left Engine LOOP A light ONLY should remain on. 

N 
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SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(7) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

 Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

 W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

 Row Col Number Name 

 B 21 B1-291 APU CONTROL 

(8) Remove jumper wire. Left Engine Loop A light shall go out. 

(9) Place jumper wire between ground and center conductor of plug that was on 

detector. Left Engine LOOP A light, FIRE DETECTOR LOOP light on the 

Annunciator Panel and MASTER CAUTION lights (for those aircraft with this 

feature) shall come back on. 

(10) Remove jumper wire Left Engine LOOP A light, FIRE DETECTOR LOOP 

light on the Annunciator Panel and MASTER CAUTION lights (for those aircraft 

with this feature) shall go off. 

 (11) Perform fire detector wire routing test for Left Engine Loop B. 

(12) Disconnect connector at either end of LOOP B element located at bottom of 

engine. 

(13) Place jumper wire between ground and center conductor of detector element. 

Left engine LOOP B light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come on. 

N 
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Page A34

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(14) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

 W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

 B 21 B1-291 APU CONTROL 

 (a) Left Engine LOOP B light ONLY should remain on. 

(15) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

 W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

 B 21 B1-291 APU CONTROL 

(16) Remove jumper wire. Left Engine Loop B light shall go out. 

(17) Place jumper wire between ground and center conductor of plug that was on 

detector. LOOP B light for left engine Loop B shall come back on. 

N 
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SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(18) Remove jumper wire. Loop light shall go off. 

(19) Place jumper wire between ground and center conductor of LOOP A detector 

element. With LOOP A and B elements grounded, verify the following. 

Left Engine Loop A and Loop B lights come on 

Fire Detector Loop light on the Annunciator Panel comes on 

Master Caution light comes on (for aircraft with this feature) 

Left Engine Fire Handle comes on 

Fire Aural Warning is heard 

(20) Remove jumper wires. Warnings shall stop. 

(21) Restore systems to normal. 

RIGHT ENGINE 

(22) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

 Row Col Number Name 

 W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

 W 34 B1-405 APU FIRE WARNING HORN 

 W 35 B1-323 FIRE DETECTORS APU LOOP A 

 W 36 B1-324 FIRE DETECTORS APU LOOP B 

 W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

 W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

 W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

 W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

 W 41 B1-280 FIRE WARNING AURAL 

 W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

 B 21 B1-291 APU CONTROL 

(23) Perform fire detector wire routing test for right engine Loop A. 

(24) Disconnect connector at either end of LOOP A element - located at bottom 

of engine. 

(25) Place jumper wire between ground and center conductor of detector element. 

Right engine LOOP A light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come on. 

N 
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Page A36

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(26) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

 (a) Right Engine Loop A light ONLY should remain on. 

(27) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(28) Remove jumper wire. Right Engine Loop A light shall go out. 

(29) Place jumper wire between ground and center conductor of plug that was on 

detector. Right Engine LOOP A light, FIRE DETECTOR LOOP light on the 

Annunciator Panel and MASTER CAUTION lights(for those aircraft with this 

feature) shall come back on. 

N 
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Page A37

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(30) Remove jumper wire. Right Engine LOOP A light, FIRE DETECTOR 

LOOP light on the Annunciator Panel and MASTER CAUTION lights (for those 

aircraft with this feature) shall go off. 

(31) Perform fire detector wire routing test for right engine Loop B. 

(32) Disconnect connector at either end of LOOP B element located at bottom of 

engine. 

(33) Place jumper wire between ground and center conductor of detector element. 

Right engine LOOP B light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come on. 

(34) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

 (a) Right engine Loop B light ONLY should remain on. 

N 
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Page A38

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(35) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(36) Remove jumper wire. Right Engine Loop B light shall go out. 

(37) Place jumper wire between ground and center conductor of plug that was on 

detector. Right Engine LOOP B , FIRE DETECTOR LOOP light on the 

Annunciator Panel and MASTER CAUTION lights(for those aircraft with this 

feature) shall come back on. 

(38) Remove jumper wire. Right Engine LOOP B light, FIRE DETECTOR 

LOOP light on the Annunciator Panel and MASTER CAUTION lights(for those 

aircraft with this feature) shall go off. 

 (39) Place jumper wire between ground and center conductor of LOOP A 

detector element. With LOOP A and B elements grounded, verify the following. 

Right Engine Loop A and Loop B lights come on 

Fire Detector Loop light on the Annunciator Panel comes on 

Master Caution light comes on (for aircraft with this feature) 

Right Engine Fire Handle comes on 

Fire Aural Warning is heard 

(40) Remove jumper wires. Warnings shall stop. 

(41) Restore systems to normal. 

(42) APU 

(43) Place APU Master Switch in RUN position. 

 

N 
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Page A39

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(44) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(45) Perform fire detector wire routing test for APU Loop A. 

(46) Disconnect connector at either end of LOOP A element - located on fwd 

side of APU enclosure inside either APU access door. 

(47) Place jumper wire between ground and center conductor of detector element. 

APU LOOP A light, FIRE DETECTOR LOOP light on the Annunciator Panel 

and MASTER CAUTION lights (for those aircraft with this feature) shall come 

on. 

(48) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

 Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS N 
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Page A40

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

 (a) APU Loop A light ONLY should remain on. 

(49) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 36 B1-324 FIRE DETECTORS APU LOOP B 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(50) Remove jumper wire. APU Loop A light shall go out. 

(51) Place jumper wire between ground and center conductor of plug that was on 

detector. APU LOOP A light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come back on. 

(52) Remove jumper wire. APU Loop A light, FIRE DETECTOR LOOP light on 

the Annunciator Panel and MASTER CAUTION lights (for those aircraft with 

this feature) shall go off. 

(53) Perform fire detector wire routing test for APU Loop B. 

(54) Disconnect connector at either end of APU LOOP B element - located on 

fwd side of APU enclosure inside either APU access door. 

(55) Place jumper wire between ground and center conductor of detector element. 

APU LOOP B light, FIRE DETECTOR LOOP light on the Annunciator Panel 

and MASTER CAUTION lights (for those aircraft with this feature) shall come 

on. 

N 
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Page A41

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(56) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

 (a) APU Loop B Loop light ONLY should remain on. 

(57) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 33 B1-814 APU FIRE CENTRAL AURAL WARNING 

W 34 B1-405 APU FIRE WARNING HORN 

W 35 B1-323 FIRE DETECTORS APU LOOP A 

W 37 B1-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 B1-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 B1-280 FIRE WARNING AURAL 

W 42 B1-192 FIRE WARNING LIGHTS 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(58) Remove jumper wire. APU Loop B light shall go out. 

N 
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SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(59) Place jumper wire between ground and center conductor of plug that was on 

detector. APU LOOP B light, FIRE DETECTOR LOOP light on the Annunciator 

Panel and MASTER CAUTION lights (for those aircraft with this feature) shall 

come back on. 

(60) Remove jumper wire. APU Loop B light, FIRE DETECTOR LOOP light on 

the Annunciator Panel and MASTER CAUTION lights (for those aircraft with 

this feature) shall go off. 

(61) Place jumper wire between ground and center conductor of LOOP A detector 

element. With LOOP A and B elements grounded, verify the following. 

APU Loop A and Loop B lights come on 

Fire Detector Loop light on the Annunciator Panel comes on 

APU FIRE light on the Annunciator Panel comes on 

Master Warning light comes on 

Master Caution light comes on (for aircraft with this feature) 

APU Fire Aural Warning 

APU Fire Warning Horn is heard 

(62) Remove jumper wires. 

APU Loop A and Loop B lights go off. 

Fire Detector Loop light on the Annunciator Panel goes off. 

APU FIRE light on the Annunciator Panel goes off. 

Master Warning light goes off. 

Master Caution light goes off (for aircraft with this feature) 

APU Fire Aural Warning goes off. 

APU Fire Warning Horn goes off. 

 

(63) Restore systems to normal. 

(64) Place APU Master Switch to the OFF position. 

(65) Open this circuit breaker: 

 OVERHEAD BATTERY BUS 

 Row Col Number Name 

B 21 B1-291 APU CONTROL 

N 
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Page A43

SCI 26-2 – MD-80 Fire Detection System Integrity Check 

(66) Operate both Loop A and Loop B test switches at the same time. 

Left Engine, Right Engine and APU Loop A and Loop B lights turn on 

APU Fire warning light goes on 

Master Warning lights go on 

Master Caution lights go on (for those aircraft with this feature) 

Fire aural warning is heard 

Left and Right Engine Fire Handle lights go on 

 

 Remove the safety tag and close this circuit breaker: 

 OVERHEAD BATTERY BUS 

Row Col Number Name 

B 21 B1-291 APU CONTROL 

(67) Restore systems to normal. 

6. Is test equipment needed?

Note: When more than one tool part number is listed under the same “Reference” 

number, the tools shown are alternates to each other within the same airplane 

series. Tool part numbers that are replaces or non-procurable are proceeded by 

“Opt:” which stands for Optional. 

Reference Description 

 None Required 

7. What is pass/fail criteria?

Pass: 

During this procedure the fire aural warning and engine fire warning lights (in the 

Firex handle) should not come on and the annunciator fire detector loop light will 

light whenever a LOOP light on the overhead panel is on. The light in the fire 

handle associated with the engine being tested should come on during the 

individual FIRE TEST. The light in the fire handle associated with the engine 

being tested should come on during the individual FIRE TEST. 

8. What is SCI interval?

The fire detection integrity test shall be performed at intervals not to exceed 27 months. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A44

SCI 26-3– MD-90 Fire Detection System Integrity Check 

1. What model does this SCI apply to?

MD-90 

2. What part or LRU is being checked?

Fire Detector Wire Routing 

3. What failure mode is being looked for?

This SCI test is to determine if fire detector wiring were crossed as a result of prior 

maintenance activities. 

 

4. How is it found?

Perform inspection per 5 below. 

5. What tasks are to be performed? 

A. Job Set-up - Engine Fire Detector Wire Routing Test 

WARNING: TAG AND USE SAFETY CLIPS TO SAFETY THE CIRCUIT BREAKERS. IF THE 

CIRCUIT 

BREAKERS ARE NOT OPENED, TAGGED, AND SAFETIED, INJURY TO PERSONS AND 

DAMAGE TO EQUIPMENT CAN OCCUR. 

(1) Deactivate the thrust reverser hydraulic control unit. (Refer to DEACTIVATION OF THE 

THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU), TASK 78-30-00-040-801 as an 

acceptable means) 

Open the lower fan cowl door. (OPENING OF THE LOWER FAN COWL DOOR, TASK 71-13-

00-010-801) 

WARNING: BE CAREFUL WHEN YOU WORK ON THE ENGINE COMPONENTS 

IMMEDIATELY 

AFTER THE ENGINE IS SHUTDOWN. THE ENGINE COMPONENTS CAN STAY HOT FOR 

UP TO ONE HOUR AND CAN CAUSE INJURY. 

CAUTION: EXTREME CARE SHOULD BE EXERCISED DURING MAINTENANCE 

PRACTICES. DO 

NOT TWIST, KINK, OR DENT THE SENSING ELEMENTS OF THE FIRE DETECTOR 

ELEMENTS. 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A45

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(2) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

B. Fire Detector Wire Routing Test 

(1) Place three loop selector switches, located on aft overhead switch panel, in BOTH position. 

Left Engine

(2) Perform fire detector wire routing test for left engine Loop A. 

(3) Disconnect wiring from fan detector at one end of LOOP A element - located at bottom of 

engine. 

(4) Place jumper wire between ground and conductor of detector element. Left engine LOOP A 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(5) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A46

SCI 26-3– MD-90 Fire Detection System Integrity Check 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Left Engine LOOP A light on FIRE DETECTION PANEL should remain on and 

LEFT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall come 

on. 

(6) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(7) Remove jumper wire. Left Engine LOOP A light on FIRE DETECTION PANEL should go off 

and LEFT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(8) Place jumper wire between ground and detector lug. Left engine LOOP A Light on FIRE 

DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC OVERHEAD 

ANNUNCIATOR PANEL {EOAP) lights shall come on. 

(9) Remove jumper wire Left Engine LOOP A light on FIRE DETECTION PANEL and FIRE 

LOOP INOP light on the ELECTRONIC OVERHEAD ANNUNCIATOR PANEL (EOAP) lights 

shall go off. Re-connect wiring to fan detector at one end of LOOP A element - located at bottom 

of engine. 

(10) Perform fire detector wire routing test for Left Engine Loop B. 

(11) Disconnect wiring from fan detector at one end of LOOP B element - located at bottom of 

engine. 

(12) Place jumper wire between ground and conductor of detector element. Left engine LOOP B 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEADANNUNCIATOR PANEL (EOAP) lights shall come on. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A47

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(13) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Left Engine LOOP Blight on FIRE DETECTION PANEL should remain on 

and LEFT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall 

come on. 

(14) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(15) Remove jumper wire. Left Engine LOOP B light on FIRE DETECTION PANEL should go 

off and LEFT 

ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. Re-connect 

wiring to fan detector at one end of LOOP B element - located at bottom of engine. 

(16) Restore systems to normal. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A48

SCI 26-3– MD-90 Fire Detection System Integrity Check 

RIGHT ENGINE

(17) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(18) Perform fire detector wire routing test for right engine Loop A. 

(19) Disconnect wiring from fan detector at one end of LOOP A element - located at bottom of 

engine. 

(20) Place jumper wire between ground and conductor of detector element. Right engine LOOP A 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(21) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Right Engine LOOP A light on FIRE DETECTION PANEL should remain on 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights 

shall come on. 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A49

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(22) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

 

(23) Remove jumper wire. Right Engine LOOP A light on FIRE DETECTION PANEL should go 

off and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(24) Place jumper wire between ground and detector lug. Right engine LOOP A Light on FIRE 

DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC OVERHEAD 

ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(25) Remove jumper wire Right Engine LOOP A light on FIRE DETECTION PANEL and FIRE 

LOOP INOP light on the ELECTRONIC OVERHEAD ANNUNCIATOR PANEL (EOAP) lights 

shall go off. Re-connect wiring to fan detector at one end of LOOP A element - located at bottom 

of engine. 

(26) Perform fire detector wire routing test for Right Engine Loop B. 

(27) Disconnect wiring from fan detector at one end of LOOP B element - located at bottom of 

engine. 

(28) Place jumper wire between ground and conductor of detector element. Right engine LOOP B 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A50

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(29) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Right Engine LOOP Blight on FIRE DETECTION PANEL should remain on 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights 

shall come on. 

(30) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(31) Remove jumper wire. Right Engine LOOP Blight on FIRE DETECTION PANEL should go 

off and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP B element - located at bottom of engine. 

(32) Restore systems to normal. 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A51

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(33) APU 

(34) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(35) Perform fire detector wire routing test for APU Loop A . 

(36) Disconnect connector at either end of LOOP A element - located on fwd side of APU 

enclosure inside either APU access door. 

(37) Place jumper wire between ground and center conductor of detector element. APU LOOP A 

light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(38) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A52

SCI 26-3– MD-90 Fire Detection System Integrity Check 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only APU Loop A light on FIRE DETECTION PANEL should remain on and APU 

FIRE DET FAULT and MASTER CAUTION lights shall come on. 

(39) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(40) Remove jumper wire. APU LOOP A light on FIRE DETECTION PANEL should go off and 

APU FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(41) Place jumper wire between ground and center conductor of plug that was on detector. APU 

LOOP A light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the 

ELECTRONIC OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(42) Remove jumper wire. APU LOOP A light on FIRE DETECTION PANEL should go off and 

APU FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. Re-connect 

wiring to fan detector at one end of LOOP A element - located at bottom of engine. 

(43) Perform fire detector wire routing test for APU Loop B. 

(44) Disconnect connector at either end of APU LOOP B element - located on fwd side of APU 

enclosure inside either APU access door. 

(45) Place jumper wire between ground and center conductor of detector element. APU LOOP 

Blight on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A53

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(46) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only APU Loop Blight on FIRE DETECTION PANEL should remain on and APU 

FIRE DET FAULT and MASTER CAUTION lights shall come on. 

(47) Close these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(48) Remove jumper wire. APU LOOP Blight on FIRE DETECTION PANEL should go off and 

APU FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(49) Place jumper wire between ground and center conductor of plug that was on detector. APU 

LOOP Blight on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A54

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(50) Remove jumper wire. APU LOOP B light on FIRE DETECTION PANEL should go off and 

APU FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP B element - located at bottom of engine. 

Remove all the tools and equipment from the work area. Make sure the area is clean. 

Close the lower fan cowl door. (CLOSING OF THE LOWER FAN COWL DOOR, TASK 71-13-

00-410-801) 

Activate the thrust reverser hydraulic control unit. (ACTIVATION OF THE THRUST 

REVERSER HYDRAULIC CONTROL UNIT, TASK 78-30-00-440-801) 

(51) Restore systems to normal. 

(52) Do an operational test of the fire detection system. (OPERATIONAL TEST OF THE 

ENGINE/APU FIRE DETECTION SYSTEM, TASK 26-11-00-710-801)

A. Job Set-up - Engine Fire Detector Wire Routing Test 

WARNING: TAG AND USE SAFETY CLIPS TO SAFETY THE CIRCUIT BREAKERS. IF THE 

CIRCUIT 

BREAKERS ARE NOT OPENED, TAGGED, AND SAFETIED, INJURY TO PERSONS AND 

DAMAGE TO EQUIPMENT CAN OCCUR. 

(1) Deactivate the thrust reverser hydraulic control unit. (DEACTIVATION OF THE THRUST 

REVERSER HYDRAULIC CONTROL UNIT (HCU), TASK 78-30-00-040-801) 

Open the lower fan cowl door. (OPENING OF THE LOWER FAN COWL DOOR, TASK 71-13-00-

010-801) 

WARNING: BE CAREFUL WHEN YOU WORK ON THE ENGINE COMPONENTS 

IMMEDIATELY 

AFTER THE ENGINE IS SHUTDOWN. THE ENGINE COMPONENTS CAN STAY HOT FOR 

UP TO ONE HOUR AND CAN CAUSE INJURY. 

CAUTION: EXTREME CARE SHOULD BE EXERCISED DURING MAINTENANCE 

PRACTICES. DO 

NOT TWIST, KINK, OR DENT THE SENSING ELEMENTS OF THE FIRE DETECTOR 

ELEMENTS. 

N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A55

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(2) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

 B. Fire Detector Wire Routing Test 

(1) Place three loop selector switches, located on aft overhead switch panel, in BOTH position. 

Left Engine

(2) Perform fire detector wire routing test for left engine Loop A. 

(3) Not Used. 

(4) On the bottom of the engine, place jumper wire between ground and terminal of LOOP A detector 

element. Left engine LOOP L-A FAULT alert shows on the STATUS/Maintenance page, FIRE 

DET L FAULT alert shows on the Engine SD page . 

(5) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A56

SCI 26-3– MD-90 Fire Detection System Integrity Check 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Left Engine LOOP L-A FAULT alert stays on the STATUS/Maintenance page, FIRE 

DET L FAULT alert on the Engine SD page goes out, FIRE DET L FAIL is shown 

on the EAD and MASTER CAUTION lights shall come on . 

(6) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(7) Remove jumper wire. Left Engine LOOP L-A FAULT alert on the STATUS/Maintenance page 

GOES off, FIRE DET L FAIL is shown on the EAD and MASTER CAUTION lights shall go 

off. 

(8) Perform fire detector wire routing test for Left Engine Loop B. 

(9) Disconnect wiring from fan detector at one end of LOOP B element - located at bottom of engine. 

(10) Place jumper wire between ground and conductor of detector element. Left engine LOOP B 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. N 
MDC-92K9145 

Revision N 

BOEING PROPRIETARY INFORMATION 

Copyright © - The Boeing Company - Unpublished Work 

Page A57

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(11) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Left Engine LOOP Blight on FIRE DETECTION PANEL should remain on and 

LEFT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall 

come on. 

(12) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(13) Remove jumper wire. Left Engine LOOP Blight on FIRE DETECTION PANEL should go off 

and LEFT 

ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP B element - located at bottom of engine. 

(14) Restore systems to normal. 

N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

RIGHT ENGINE

(15) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(16) Perform fire detector wire routing test for right engine Loop A. 

(17) Disconnect wiring from fan detector at one end of LOOP A element - located at bottom of 

engine. 

(18) Place jumper wire between ground and conductor of detector element. Right engine LOOP A 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL {EOAP) lights shall come on. 

(19) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Right Engine LOOP A light on FIRE DETECTION PANEL should remain on 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights 

shall come on. 

(20) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(21) Remove jumper wire. Right Engine LOOP A light on FIRE DETECTION PANEL should go off 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(22) Place jumper wire between ground and detector lug. Right engine LOOP A Light on FIRE 

DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC OVERHEAD 

ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(23) Remove jumper wire Right Engine LOOP A light on FIRE DETECTION PANEL and FIRE 

LOOP INOP light on the ELECTRONIC OVERHEAD ANNUNCIATOR PANEL (EOAP) lights 

shall go off. Re-connect wiring to fan detector at one end of LOOP A element - located at bottom 

of engine. 

(24) Perform fire detector wire routing test for Right Engine Loop B. 

(25) Disconnect wiring from fan detector at one end of LOOP B element - located at bottom of 

engine. 

(26) Place jumper wire between ground and conductor of detector element. Right engine LOOP B 

Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

(27) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only Right Engine LOOP Blight on FIRE DETECTION PANEL should remain on 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights 

shall come on. 

(28) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(29) Remove jumper wire. Right Engine LOOP Blight on FIRE DETECTION PANEL should go off 

and RIGHT ENG FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP 8 element - located at bottom of engine. 

(30) Restore systems to normal. N 
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Revision N 

BOEING PROPRIETARY INFORMATION 

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Page A61

SCI 26-3– MD-90 Fire Detection System Integrity Check 

(31) APU 

(32) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(33) Perform fire detector wire routing test for APU Loop A. 

(34) Disconnect connector at either end of LOOP A element - located on fwd side of APU enclosure 

inside either APU access door. 

(35) Place jumper wire between ground and center conductor of detector element. APU LOOP A light 

on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on. 

(36) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only APU Loop A light on FIRE DETECTION PANEL should remain on and APU 

FIRE DET FAULT and MASTER CAUTION lights shall come on. 

(37) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(38) Remove jumper wire. APU LOOP A light on FIRE DETECTION PANEL should go off and 

APU FIRE DET 

FAULT on EOAP and MASTER CAUTION lights shall go off. 

(39) Place jumper wire between ground and center conductor of plug that was on detector. APU 

LOOP 

A light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD 

ANNUNCIATOR PANEL (EOAP) lights sha ll come on. 

(40) Remove jumper wire. APU LOOP A light on FIRE DETECTION PANEL should go off and 

APU FIRE DET 

FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP A element - located at bottom of engine. 

(41) Perform fire detector wire routing test for APU Loop B. 

(42) Disconnect connector at either end of APU LOOP B element - located on fwd side of APU 

enclosure inside either APU access door. 

(43) Place jumper wire between ground and center conductor of detector element. APU LOOP Blight 

on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEAD ANNUNCIATOR PANEL (EOAP) lights shall come on . N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

(44) Open these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

a. Only APU Loop Blight on FIRE DETECTION PANEL should remain on and APU 

FIRE DET FAULT and MASTER CAUTION lights shall come on. 

(45) Close these circuit breakers: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 33 Bl-814 APU FIRE CENTRAL AURAL WARNING 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 B1-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 B1-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

 OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(46) Remove jumper wire. APU LOOP Blight on FIRE DETECTION PANEL should go off and 

APU FIRE DET FAULT on EOAP and MASTER CAUTION lights shall go off. 

(47) Place jumper wire between ground and center conductor of plug that was on detector. APU 

LOOP Light on FIRE DETECTION PANEL and FIRE LOOP INOP light on the ELECTRONIC 

OVERHEADANNUNCIATOR PANEL (EOAP) lights shall come on. N 
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SCI 26-3– MD-90 Fire Detection System Integrity Check 

(48) Remove jumper wire. APU LOOP B light on FIRE DETECTION PANEL should go off and 

APU FIRE DET 

FAULT on EOAP and MASTER CAUTION lights shall go off. 

Re-connect wiring to fan detector at one end of LOOP B element - located at bottom of engine. 

Remove all the tools and equipment from the work area. Make sure the area is clean. 

Close the lower fan cowl door. (CLOSING OF THE LOWER FAN COWL DOOR, TASK 71-13-00-

410-801) 

Activate the thrust reverser hydraulic control unit. (ACTIVATION OF THE THRUST REVERSER 

HYDRAULIC CONTROL UNIT, TASK 78-30-00-440-801) 

(49) Restore systems to normal. 

(50) Do an operational test of the fire detection system. (OPERATIONAL TEST OF THE 

ENGINE/APU FIRE DETECTION SYSTEM, TASK 26-11-00-710-801) 

6. Is test equipment needed?

Note: When more than one tool part number is listed under the same “Reference” 

number, the tools shown are alternates to each other within the same airplane 

series. Tool part numbers that are replaces or non-procurable are proceeded by 

“Opt:” which stands for Optional. 

Reference Description 

 None Required 

7. What is pass/fail criteria?

Pass: 

During this procedure the fire aural warning and engine fire warning lights (in the 

Firex handle) should not come on and the annunciator fire detector loop light will 

light whenever a LOOP light on the overhead panel is on. 

8. What is SCI interval?

The fire detection integrity test shall be performed at intervals not to exceed 27 months. 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

1. What model does this SCI apply to?

717-200 

2. What part or LRU is being checked?

Fire Detector Wire Routing 

3. What failure mode is being looked for?

This SCI test is to determine if fire detector wiring were crossed as a result of prior 

maintenance activities. 

4. How is it found?

Perform inspection per 5 below. 

5. What tasks are to be performed?

A. Job Set-up - Engine Fire Detector Wire Routing Test 

WARNING: TAG AND USE SAFETY CLIPS TO SAFETY THE CIRCUIT BREAKERS. 

IF THE CIRCUIT BREAKERS ARE NOT OPENED, TAGGED, AND SAFETIED, 

INJURY TO PERSONS AND DAMAGE TO EQUIPMENT CAN OCCUR. 

(1) Deactivate the thrust reverser hydraulic control unit. (DEACTIVATION OF THE 

THRUST 

 REVERSER HYDRAULIC CONTROL UNIT (HCU), TASK 78-30-00-040-801) 

(2) Open the lower fan cowl door. 

(3) Make sure that these circuit breakers are closed: 

 LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 41 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 31 Bl-280 APU READY RELAY 

W 42 Bl-192 FIRE WARNING LIGHTS 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

OVERHEAD BATIERY BUS 

Row Col Number Name

Z 39 Bl-291 APU CONTROL 

B. Fire Detector Wire Routing Test 

(1) Place three loop selector switches, located on aft overhead switch panel, in BOTH 

position. 

 Left Engine 

(2) Perform fire detector wire routing test for left engine Loop A. 

(3) On the bottom of the engine, place jumper wire between ground and terminal of LOOP A 

detector element. 

(4) Left engine FIRE L-A FAULT Alert shows on the STATUS/Maintenance page. 

(5) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 40 81-281 FIRE DETECTORS LEFT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 81-291 APU CONTROL 

(6) Left Engine FIRE L-A FAULT, FIRE L-B FAULT alert on the STATUS/Maintenance 

page is ON and FIRE DET L FAIL shows on the EAD and MASTER CAUTION Lights 

will come on. 

(7) Close this circuit breaker: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

(8) Remove jumper wire. 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

(9) Left Engine FIRE L-A FAULT, FIRE L-B FAULT alert on the STATUS/Maintenance 

page goes OFF and FIRE DET L FAIL goes OFF on the EAD and MASTER CAUTION 

Lights will go OFF. 

(10) Place the Left Engine Fuel Shutoff switch to ON. 

(11) Push and Hold the FIRE TEST switch. 

(a) Fire bell alarm comes ON. 

(b) Voice Warning comes ON: FIRE LEFT ENGINE 

(c) Lights in the LEFT ENG FIRE handle come ON. 

(d) The following alert messages are shown on the EAD: 

(1) ENGINE L FIRE 

(2) PODS TEST PASS. 

(e) On the glareshield, both MASTER WARNING lights come ON. 

(f) On the forward pedestal, the LEFT Fuel switch light comes ON. 

(g) Place the RIGHT Engine Fuel Shutoff switch to ON. 

(h) Pull the Left Engine Fire Handle out until the Fire Bell and Voice Warning are OFF. 

(1) Left Engine Fuel Shutoff Switch light is ON and Right Engine Fuel Shutoff 

Switch light is OFF. 

(i) Push the Left Engine Fire Handle in and the Fire Bell and Voice Warning are ON. 

(j) Place the RIGHT Engine Fuel Shutoff switch to OFF. 

(12) Release the FIRE TEST Switch 

(a) The fire bell is silent. 

(b) The lights in the LEFT ENG FIRE handle goes OFF. 

(c) The fuel switch light goes OFF. 

(e) The following alert messages are not shown on the EAD: ENGINE L FIRE 

(f) On the glareshield, both MASTER WARNING lights go OFF. 

(g) On the forward pedestal, the LEFT Fuel switch light goes OFF. 

 (11)Perform fire detector wire routing test for Left Engine Loop B. 

(12) On the bottom of the engine, place jumper wire between ground and terminal of LOOP 

B detector element. 

(13) Left engine LOOP L-B FAULT alert shows on the STATUS/Maintenance page. 

(14) Push and Hold the FIRE TEST switch. 

(a) Fire bell alarm comes ON. 

(b) Voice Warning comes ON: FIRE LEFT ENGINE 

(c) Lights in the LEFT ENG FIRE handle come ON. 

(d) The following alert messages are shown on the EAD: 

(1) ENGINE L FIRE 

(2) PODS TEST PASS. 

(e) On the glareshield, both MASTER WARNING lights come ON. 

(f) On the forward pedestal, the LEFT Fuel switch light comes ON. 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

 

 (15) Release the FIRE TEST Switch 

(a) The fire bell is silent. 

(b) The lights in the LEFT ENG FIRE handle goes OFF. 

(c) The fuel switch light goes OFF. 

 (d) The following alert messages are not shown on the EAD: ENGINE L FIRE 

(e) On the glareshield, both MASTER WARNING lights go OFF. 

(f) On the forward pedestal, the LEFT Fuel switch light comes OFF. 

 (16) Remove jumper wire. 

 (17) Left Engine LOOP L-B FAULT alert on the STATUS/Maintenance page GOES off. 

 (18) Close these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 BI-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

 (19) Place LEFT Engine Fuel Switch to OFF 

 (20) Restore systems to normal. 

RIGHT ENGINE 

 (21) Make sure that these circuit breakers are closed: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

OVERHEAD BATIERY BUS 

Row Col Number Name 

B 21 Bl-291 APU CONTROL 

 (22) Perform fire detector wire routing test for right engine Loop A. 

(23) On the bottom of the engine, place jumper wire between ground and terminal of LOOP A 

detector element. 

(24) Right engine LOOP R-A FAULT alert shows on the STATUS/Maintenance page. 

(25) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name 

B 21 Bl-291 APU CONTROL 

(26) Right Engine LOOP RA FAULT alert stays on the STATUS/Maintenance page, FIRE 

DETR FAULT alert 

 on the Engine SD page stays on . 

(27) Place the Right Engine Fuel Shutoff switch to ON. 

(28) Push and Hold the FIRE TEST switch. 

(a) Fire bell alarm comes ON. 

(b) Voice Warning comes ON: FIRE RIGHT ENGINE 

(c) Lights in the RIGHT ENG FIRE handle come ON. 

(d) The following alert messages are shown on the EAD: 

(1) ENGINE R FIRE 

(2) PODS TEST PASS. 

(e) On the glareshield, both MASTER WARNING lights come ON. 

(f) On the forward pedestal, the RIGHT Fuel switch light comes ON. 

(g) Place the LEFT Engine Fuel Shutoff switch to ON. 

(h) Pull the Right Engine Fire Handle out until the Fire Bell and Voice Warning are OFF. 

(1) Right Engine Fuel Shutoff Switch light is ON and Left Engine Fuel Shutoff 

Switch light 

is OFF. 

(i) Push the Right Engine Fire Handle in and the Fire Bell and Voice Warning are ON. 

(j) Place the LEFT Engine Fuel Shutoff switch to OFF. 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

(29) Release the FIRE TEST Switch 

(a) The fire bell is silent. 

(b) The lights in the RIGHT ENG FIRE handle goes OFF. 

(c) The fuel switch light goes OFF. 

(d) The following alert messages are not shown on the EAD: ENGINE R FIRE 

(e) On the glareshield, both MASTER WARNING lights go OFF. 

(f) On the forward pedestal, the RIGHT Fue l switch light comes OFF. 

(30) Remove jumper wire. Left Engine LOOP R-A FAULT alert on the STATUS/Maintenance 

page GOES off, FIRE DETR FAIL is shown on the EAD goes off. 

(31) Close these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

OVERHEAD BATTERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(32) Perform fire detector wire routing test for right engine Loop B. 

(33) Make sure that these circuit breakers are closed: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl -282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

OVERHEAD BATTERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(34) On the bottom of the engine, place jumper wire between ground and terminal of LOOP B 

detector element. 

N 
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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

(35)Right engine LOOP R-B FAULT alert shows on the STATUS/Maintenance page, FIRE 

DETR FAULT alert shows on the Engine SD page. 

(36) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name 

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(37) Right Engine LOOP R-A FAULT alert stays on the STATUS/Maintenance page, FIRE 

DETR FAULT alert on the Engine SD page stays on. 

(38) Place the Right Engine Fuel Shutoff switch to ON. 

(39) Push and Hold the FIRE TEST switch. 

(a) Fire bell alarm comes ON. 

(b) Voice Warning comes ON: FIRE RIGHT ENGINE 

(c) Lights in the RIGHT ENG FIRE handle come ON. 

(d) The following alert messages are shown on the EAD: 

(1) ENGINE R FIRE 

(2) PODS TEST PASS. 

(e) On the glareshield, both MASTER WARNING lights come ON. 

(f) On the forward pedestal, the RIGHT Fuel switch light comes ON. 

(40) Release the FIRE TEST Switch 

(a) The fire bell is silent. 

(b) The lights in the RIGHT ENG FIRE handle goes OFF. 

(c) The fuel switch light goes OFF. 

(d) The following alert messages are not shown on the EAD: ENGINE R FIRE 

(e) On the glareshield, both MASTER WARNING lights go OFF. 

(f) On the forward pedestal, the RIGHT Fuel switch light goes OFF 

(41) Remove jumper wire. Left Engine LOOP R-B FAULT alert on the STATUS/Maintenance 

page GOES off, FIRE DETR FAIL is shown on the EAD goes off. 

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(42) Close these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(43) Place Right Engine Fuel Shutoff Switch to OFF. 

(44) Restore systems to normal. 

APU 

(45) Make sure that these circuit breakers are closed: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(46) Perform fire detector wire routing test for APU Loop A. 

(47) On fwd side of APU enclosure inside either APU access door, place a jumper wire between 

ground and terminal of LOOP A detector element. 

(49) LOOP APU A FAULT alert shows on the STATUS/Maintenance page, FIRE DET APU 

FAULT alert shows on the Engine SD page. 

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(50) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(51) LOOP APU A FAULT alert stays on the STATUS/Maintenance page, FIRE DET APU 

FAULT alert on the 

Engine SD page stays on. 

(52) Push and Hold the FIRE TEST switch. 

(a) The following alert messages are shown on the EAD: 

(1) APU FIRE 

(2) PODS TEST PASS . 

(c) On the glareshield, both MASTER WARNING lights come ON. 

(53) Release the FIRE TEST Switch 

(a) The following alert messages are not shown on the EAD: 

(1) APU FIRE 

(b) On the glareshield, both MASTER WARNING lights go OFF. 

(54) Remove jumper wire. 

(59) LOOP APU A FAULT alert goes OFF the STATUS/Maintenance page, FIRE DET APU 

FAULT alert on the Engine SD page goes OFF. 

(61) Perform fire detector wire routing test for APU Loop B. 

(62) Make sure that these circuit breakers are closed: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 35 Bl-323 FIRE DETECTORS APU LOOP A 

W 36 Bl-324 FIRE DETECTORS APU LOOP B 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

W 41 Bl-280 FIRE WARNING AURAL 

W 42 Bl-192 FIRE WARNING LIGHTS 

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OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(63) On fwd side of APU enclosure inside either APU access door, place jumper wire between 

ground and terminal of LOOP B detector element. 

(65) LOOP APU B FAULT alert shows on the STATUS/Maintenance page, FIRE DET APU 

FAULT alertshows on the Engine SD page. 

(66) Open these circuit breakers: 

LOWER EPC, DC TRANSFER BUS 

Row Col Number Name

W 34 Bl-405 APU FIRE WARNING HORN 

W 37 Bl-59 FIRE DETECTORS RIGHT ENGINE LOOP A 

W 38 Bl-191 FIRE DETECTORS RIGHT ENGINE LOOP B 

W 39 Bl-282 FIRE DETECTORS LEFT ENGINE LOOP A 

W 40 Bl-281 FIRE DETECTORS LEFT ENGINE LOOP B 

OVERHEAD BATIERY BUS 

Row Col Number Name

B 21 Bl-291 APU CONTROL 

(67) LOOP APU B FAULT alert stays on the STATUS/Maintenance page, FIRE DET APU 

FAULT alert on the 

Engine SD page stays on. 

(68) Push and Hold the FIRE TEST switch. 

(a) The following alert messages are shown on the EAD: 

(1) APU FIRE 

(2) PODS TEST PASS. 

(b) On the glareshield, both MASTER WARNING lights come ON. 

(69) Release the FIRE TEST Switch 

(a) The following alert messages are not shown on the EAD: 

(1) APU FIRE 

(b) On the glareshield, both MASTER WARNING lights go OFF. 

(70) Remove jumper wire . 

(76) LOOP APU B FAULT alert goes OFF the STATUS/Maintenance page, FIRE DET APU 

FAULT alert on the Engine SD page goes OFF. 

(78) Remove all the tools and equipment from the work area. Make sure the area is clean. 

(79) Close the lower fan cowl door. (CLOSING OF THE LOWER FAN COWL DOOR, 

TASK 71-13-00-410-801) 

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SCI 26-4 – 717-200 Fire Detection System Integrity Check 

(80) Activate the thrust reverser hydraulic control unit. (ACTIVATION OF THE THRUST 

REVERSER 

HYDRAULIC CONTROL UNIT, TASK 78-30-00-440-801) 

(81) Restore systems to normal. 

(82) Do Operational Test of the Engine Fire Detection System. (OPERATIONAL TEST OF THE 

ENGINE/APU FIRE DETECTION SYSTEM, TASK 26-11-00-700-801) 

6. Is test equipment needed? 

Note: When more than one tool part number is listed under the same “Reference” 

number, the tools shown are alternates to each other within the same airplane 

series. Tool part numbers that are replaces or non-procurable are proceeded by 

“Opt:” which stands for Optional. 

Reference Description 

 None Required 

7. What is pass/fail criteria?

Pass: 

During this procedure the fire aural warning and engine fire warning lights (in the 

Firex handle) should not come on and the annunciator fire detector loop light will 

light whenever a LOOP light on the overhead panel is on. The light in the fire 

handle associated with the engine being tested should come on during the 

individual FIRE TEST. 

8. What is SCI interval?

The fire detection integrity test shall be performed at intervals not to exceed 27 months. 

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Appendix B 

Critical Design Configuration Control Limitations (CDCCLs) 
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TWINJET CRITICAL DESIGN CONFIGURATION CONTROL LIMITATIONS 

For some twinjet system functions, for compliance with SFAR 88 and Advisory Circular (AC) 

25.981-1B, limitations for certain SFAR88 design configurations are required using AC 25-19 

“Certification Maintenance Requirements (CMRs)” methodology as a guide. 

Critical Design Configuration Control Limitations (CDCCLs) are a means of notifying the FAA, 

operators, and maintenance facilities of certain design configuration aspects that cannot be 

changed without violating the design intent, potentially making the airplane non-compliant with 

FAR 25.981(b). Therefore, these configuration aspects must be controlled such that they remain 

in the configuration as specified in each CDCCL. 

The following CDCCLs are features that Boeing has identified as not obvious or intuitive that a 

change could impact safety. This list is not inclusive of every potential change or feature that is 

possible. For example, changing a circuit breaker to a higher current rating is not covered here 

because such a change obviously needs to be evaluated for impact to the circuit it protects. 

Changing a wire to a smaller gauge would have to be evaluated to determine if it could carry the 

required currents. However, a change to a larger wire gauge has in the past been allowed 

without specific assessment, but this could increase the chance of a tank wall burn through so it 

is identified as a CDCCL. Any change or repair to any part of the aircraft not performed in 

accordance with OEM published data must be assessed by the modifier for safety and 

certification impact per the FARs; any changes or repairs performed in accordance with OEM 

published date prior to the CDCCL compliance time do not require reassessment. This list is 

only an aid to the operator and to the FAA in evaluating future fuel system related repairs and 

changes for potential tank ignition risk. 

The terms of the appropriate twinjet Type Certificate are only valid when the design 

configuration aspects specified by these CDCCLs are maintained as stated. The configuration 

control limitations are mandatory and cannot be changed or deleted without the approval of FAA 

Engineering of the Los Angeles Aircraft Certification Office (LA-ACO). 

SFAR88 established requirements for CDCCLs; it includes an implementation schedule for 

changes to the operator’s control documents to manage compliance with these limitations. 

While each CDCCL is included in this report, it is required that each CDCCL also be included in 

an appropriate document where it will be visible to airline personnel; therefore each CDCCL 

configuration control information must be included in each Operator's appropriate maintenance 

documentation. 

All maintenance and repair instructions provided by Boeing have been updated where required 

to ensure compatibility with these design limitations. 

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Each CDCCL specified herein includes the name of the system in which the CDCCL is needed, 

and the following information: 

1. What model twinjet does this CDCCL apply to? 

2. What part, LRU or system is the CDCCL levied against? 

3. What characteristic of the design configuration for this item must be retained under control of 

this Limitation, and why? 

4. What is the specific Limitation? 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the Original 

Equipment Manufacturer (OEM)? If not, is there an applicable Service Bulletin or Service 

Rework package required for some aircraft? 

6. When does this CDCCL become effective? 
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CDCCL 20-1 - Twinjet Repair Wire Gauges 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Any repair wiring used inside or within 6” of the fuel tanks and fuel pipes. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Adverse excessive temperatures that could result from wire arcing events are 

characterized for a limited, known set of OEM-approved wire gauges. 

4. What is the specific Limitation? 

Any repair wiring inside or within 6” of the fuel tanks and fuel pipes must use the same 

wire gauge as the wire being replaced. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-2 - Twinjet FQIS Wire Isolation 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Fuel Quantity Indication System (FQIS) wiring. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

FQIS wires must be isolated or separated from other aircraft wiring, to prevent chafing 

that can lead to shorting to an incompatible power source. 

4. What is the specific Limitation? 

FQIS wires (as defined below) must maintain isolation from other aircraft wiring or have 

an integral physical barrier (as part of the approved FQIS wire construction). 

FQIS Wire Bundle Definition

DC-9 - Master Indicator to Tank entry points 

MD-80/MD-90/717 – Standard Electronic Module (SEM) to Tank entry points 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply (for Fuselages 5100 thru 5127, a 

portion of the wiring at the front of the SEM is not separated; it is 

found to be safe with no rework required). 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-3 - Twinjet In-Tank Wire Splices 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Any wiring inside the fuel tanks, including those routed in conduit located inside the fuel 

tank. 

 Wiring going to AC and DC fuel pumps. 

 Wiring belonging to the fuel quantity gauging system (FQGS). 

 Wiring going to fuel high-level and low-level float switches (as applicable). 

 Wiring going to wing upper skin ice detectors (as applicable). 

This does not include wiring inside a LRU. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Wiring inside fuel tanks shall not contain splices, including wiring within in-tank 

conduits. 

Splices may allow fuel penetration to the conductors of the spliced wires. 

A deteriorated wire splice could result in a high resistance electrical path, higher than 

allowable wire temperatures, arcing and/or breach of the conduit assembly. 

Improper shielding/insulation at the splice could result in arcing to the conduit and 

breach of the conduit assembly. 

4. What is the specific Limitation? 

Splices of any type, including crimp or solder type, shall not be allowed on wires in the 

fuel tank or on wires inside conduits that are in the fuel tank. 
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CDCCL 20-3 - Twinjet In-Tank Wire Splices 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-4 - Twinjet Repair Wire Types 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Any repair wiring used inside or within 6” of the fuel tanks and fuel pipes. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Adverse excessive temperatures that could result from wire arcing events are 

characterized for a limited, known set of OEM-approved wire gauges. 

4. What is the specific Limitation? 

Any repair wiring used inside or within 6” of the fuel tanks and fuel pipes cannot use any 

of the following wire types: 

1. DES-SM2006 (PVC/Nylon) 

2. 7484444 (“Quad 4”, PVC/Fiberglass/Nylon) 

3. 7616964 (PVC/Nylon & PVC/Fiberglass/Nylon) 

4. 7706560 (MIL-W-81044/9, XL-Polyolefin/XL-Kynar) 

5. 7891145 (was Poly-X, then later was Stilan) 

6. BXS7007 (Aromatic Polyimide) 
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CDCCL 20-4 - Twinjet Repair Wire Types 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series Aircraft as originally built with previously approved wire types are 

acceptable. New repairs should only be made with OEM approved 

wire types. 

MD-80 Series Aircraft as originally built with previously approved wire types are 

acceptable. New repairs should only be made with OEM approved 

wire types. 

MD-90 Series Aircraft as originally built with previously approved wire types are 

acceptable. New repairs should only be made with OEM approved 

wire types. 

717 Series Aircraft as originally built with previously approved wire types are 

acceptable. New repairs should only be made with OEM approved 

wire types. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-5 - Twinjet Wire Installations 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Any wiring used within 6” of fuel tanks and fuel pipes. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Adverse excessive temperatures that could result from wire arcing events are 

characterized for a limited, known set of OEM-approved wire distance to the fuel tank 

walls or pipes. 

4. What is the specific Limitation? 

Repair of wiring within 6” of fuel tanks and fuel pipes must use existing wire routing and 

clipping established per OEM-approved wire installation or maintain wire clearances as 

prescribed in the applicable sections of SWPM 20-00-06 and/or SWPM 20-10-01. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-6 - Twinjet Prohibition of Power Feeder Splices in Areas Above Fuel Tanks 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Power feeders above any fuel tank. 

Power feeders are defined as any wire 10 gauge and larger (10, 8, 6, 4, 2, 0, 00, 000, and 

0000 wire gauges). 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Maintain wire continuity over fuel tanks without breaks. This will prevent adverse 

temperature effects on the fuel tank due to a potential splice failure. 

4. What is the specific Limitation? 

Power Feeders above any fuel tank shall be maintained without splices. Any needed 

repair splice needs to be implemented at a location at least 3 feet or 2 wire supports 

(whichever is further) from the fuel tank boundaries. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-7 – 717 Float Switch Conduit Sleeves 

1. What twinjet model does this CDCCL apply to? 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

High Level Float Switch Conduit. 

Low Level Float Switch Conduit. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Teflon® hoses are to be installed inside the float switch conduits to provide wire 

protection from chafing and shorting to the conduit wall. 

4. What is the specific Limitation? 

Any replacement work must have Teflon® hose installed as built by the OEM. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-8 - Twinjet Fuel Tank Access Door Bonding 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

All fuel tank access doors 

3. What characteristic of the design configuration for this item must be retained under 

control of this limitation, and why? 

Electrical current paths are defined by the installation and bonding processes in the 

relevant OEM fuel tank access door and access door installation design drawings. The 

paths are intended to conduct lightning current flowing along the skin, across the doors, 

or to disperse lightning current from an attachment point on an attach bolt, or a door, to 

the skin without arcing/sparking. The effectiveness of the conductive paths depends on 

specific surface treatments, sealants, sealing procedures, seals, o-rings, fastener types, 

materials, conductive rubstrips, interference fit fasteners, and coatings. 

The non-conductive features of the door installation shall also be maintained as they help 

to direct current flow to the conductive path. This includes anodizing, priming and 

sealing, as well as the seals (a type of rubber O-ring) on the door and the dome nuts. 

Departing from the OEM designed electrical current path across different interfaces 

could create hazardous ignition sources inside the tank. 

4. What is the specific limitation? 

The conductive and non conductive path design which includes specific surface 

treatments, sealants, sealing procedures, seals, o-rings, fastener types, materials, 

conductive rubstrips, interference fit fasteners, and coatings must be maintained per 

OEM design data which includes Boeing design drawings or the Boeing SRM or the 

Boeing AMM or Boeing approved repairs or any combination of those. 
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CDCCL 20-8 - Twinjet Fuel Tank Access Door Bonding 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-9 – 717/MD-80/MD-90 Wing Root Area Lightning Protection

1. What twinjet model does this CDCCL apply to? 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Sheet metal aluminum straps in the wing leading edge area of the wing fillet connecting the 

ribs together and connecting the ribs to the fuselage. Also the overbraid shielding and or 

wire shield, depending on the model, and their grounding at both ends. 

3. What characteristic of the design configuration for this item must be retained under 

control of this limitation, and why? 

The intense electromagnetic field created by lightning current in the wing root area is 

attenuated by a number of metal straps between the wing forward section (leading edge) at 

the most inboard rib and the fuselage. Depending on the model, the wire harnesses in the 

wing root area could be further protected with metal overbraid shields, grounded at both 

ends. In some models the wire shields, grounded at both ends, could be additional or only 

protection provided for some of the wiring. These straps and shields, as defined in the 

relevant OEM drawings provide lightning protection to the aircraft equipment interfaced 

with the wires spanning across the wing root area. 

The straps, as defined in the applicable OEM drawings, must be continuous and unbroken, 

the low-resistance electrical bonds at the two ends must be maintained. The overbraid must 

be continuous and undamaged by cuts, fraying, corrosion or other defects. The lowresistance bonds or grounds must be maintained at both ends of the overbraid/wire shield for 

it to be effective. 

All replacement wires in the wing-root area require lightning protection to prevent induced 

transients from contaminating and threatening other aircraft systems in common wire harness 

inside the aircraft and wing. 

The lightning protection in the wing root area for different models are as follows: 

- MD-80/-90: Aluminum straps, and wire shields (grounded at both ends) for some of the 

wiring. 

- 717: Aluminum straps and metal overbraid shielding (grounded at both ends) for all 

wiring. 
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CDCCL 20-9 – 717/MD-80/MD-90 Wing Root Area Lightning Protection

(cont’d) 

4. What is the specific limitation? 

Do not alter or remove the wing-root area lightning protection straps, wire overbraids and 

shields. Any replacement wires in this area must also be shielded/overbraided in the same 

manner, with the overbraids grounded at both ends. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-10 - Twinjet Fuel Tank Structural Design 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Fuel tank structure. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

The electrical bonding path must be maintained at all tank penetrations and applicable 

equipment mounting brackets internal and external to the tank. Specifically the types of 

surface preparation prior to assembly and types of fasteners used must assure that all 

mechanical joints and penetrations can handle the lightning currents at the respective 

locations. The non-conductive features (anodizing, priming, painting and sealing) also must 

be preserved, since they could be part of the design to direct current to the conductive parts, 

prevent arcing at specific locations or contain minor arcing. 

4. What is the specific Limitation? 

The conductive and non conductive path design which includes specific surface treatments, 

sealants, sealing procedures, fastener types, and coatings must be maintained per OEM 

design data which includes Boeing design drawings or the Boeing SRM or the Boeing AMM 

or Boeing approved repairs or any combination of those. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 
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CDCCL 20-10 - Twinjet Fuel Tank Structural Design 

(cont’d) 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-11 – DC-9 Auxiliary Hydraulic Pump Conduit 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

2. What part, LRU or system is the CDCCL levied against? 

Auxiliary Hydraulic Pump conduit. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Auxiliary Hydraulic Pump wiring installed in metallic conduit in the either main 

wheelwell provides wire protection from chafing and potential shorts. 

4. What is the specific Limitation? 

Auxiliary Hydraulic Pump wiring must be installed in metallic conduit and maintained per 

SWPM 20-10-14

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-12 - Twinjet Wiring Near Fuel Tanks and Fuel Pipes 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

All wiring used near the fuel tanks and fuel pipes. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Proper wire assembly and wire installation techniques, wire bundle cleanliness, and 

adherence to the following requirements will minimize the likelihood that severe 

overheat or burn-through events will occur near fuel tanks and certain fuel pipes. 

4. What is the specific Limitation? 

Wires/wire assemblies, when installed within 6 inches of any fuel tank or fuel pipe, shall 

conform to Standard Wiring Practice Manual (Boeing Document Number D6-82481), 

Section 20-00-06. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 
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CDCCL 20-13 – DC-9/MD-80/MD-90/717 Float and Pressure Switch Circuit 

1. What model Twinjet does this CDCCL apply to? 

 DC-9 Series 

 MD-80 Series 

 MD-90 Series 

 717 Series 

2. What part, LRU or system is the CDCCL levied against? 

The fuse and DMS 2109 or DMS 2379 Type 4 sleeving material installed over the 

powered wire leads from the fuse to tank penetration point on float and pressure switch 

circuits. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

The fuse must be installed to protect the circuit. 

DMS 2109 or DMS 2379 Type 4 sleeving material must be installed between the fuse 

and the tank penetration point, to isolate the power lead from other wiring and provide 

additional wire protection from chafing and shorting. 

For fuse installations that incorporate a drip loop near the fuse, sleeving will only extend 

from tank penetration point to bottom of the drip loop. 

4. What is the specific Limitation? 

Any replacement fuse must be the same type and rating as defined in the applicable 

service bulletin or per SWPM 20-20-02 

Any replacement or repair of wiring or sleeving from the fuse to tank penetration point 

must have DMS 2109 or DMS 2379 Type 4 sleeving installed per SWPM 20-10-01 or in 

accordance with the applicable service bulletin. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

Original Equipment Manufacturer (OEM)? If not, is there an applicable Service Bulletin 

or Service Rework package required for some aircraft? 

DC-9 Series Service Bulletin DC9-28-217 revision New or later 

Service Bulletin DC9-28-217 revision 1 or later for the fuselage 

numbers listed below. 

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CDCCL 20-13 – DC-9/MD-80/MD-90/717 Float and Pressure Switch Circuit 

(cont’d) 

Fuselage Number 

281 304 340 377 399 

421 438 458 530 539 

548 552 647 650 653 

656 659 662 665 668 

670 686 692 696 698 

700 702 704 707 765 

769 774 784 786 795 

801 809 811 843 934 

954 982 1081 1084 

MD-80 Series Service Bulletin MD80-28-226 revision New or later 

MD-90 Series Service Bulletin MD90-28-012 revision New or later 

 717 Series Ships 5151 and subs were delivered within compliance 

 Service Bulletin 717-28-014 revision New or later for all others. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective after incorporation of Service Bulletin DC9-28-217, 

MD80-28-226, MD90-28-012, or 717-28-014 as applicable. 

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CDCCL 28-1 – Twinjet Prohibit Safety Wire, Lockwire, Safety Cable or Cotter Pins 

Inside Fuel Tanks 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Inside airplane fuel tanks. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

The use of safety wire, lockwire, safety cable or cotter pins within fuel tanks are not 

permitted. 

Safety wire, lockwire, safety cable or cotter pins could become loose and have the 

potential to become FOD (foreign object debris) and cause filament heating, or arcing. 

4. What is the specific Limitation? 

Safety wire, lockwire, safety cable or cotter pins are not to be installed inside the fuel 

tanks. Components or equipment installed inside fuel tanks shall not use safety wire or 

cotter pins for hardware retention. Safety wire, lockwire, safety cable and cotter pins 

may be used if they are contained within the housing of an explosion proof, tank mounted 

LRU, and must be installed per applicable Original Equipment Manufacture (OEM) 

design/repair/ maintenance documentation. In-shop LRU repairs must adhere to OEM 

Component Maintenance Manual (CMM) documented procedures and sole use of parts 

specified in the OEM’s CMM. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-2 - Twinjet Fuel Pump (Boost or Transfer) and Housing Assemblies 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Tank mounted electrically operated fuel pumps. Affected parts are: 

 Nash Fuel Pump part number 65-5093-4 and associated volute part numbers 65-

5094-1, 65-5094-3, 65-5094-2, 65-5095-1, 65-5095-3 

 Nash Fuel Pump Volute part numbers 65-5107-1, 65-5107-2. 

 Nash Fuel Pump Volute part numbers 65-5095-2, 65-5095-4 

 TRW / Argo-Tech Fuel Pump part numbers 398000-1, 398000-and associated 

volute part numbers 399300-2, 399500-1, 702200-1, 702300-1. 

 Lear-Romec Fuel Pump part number RR12551A and associated volute part 

number RR12552A. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Fuel pumps must be maintained to protect: 

 original Explosion-proof features, 

 electrical circuit integrity, 

 impeller and housing material, 

 protection from FOD ingestion, 

 bonding paths, 

 prevent exposure to mercury, and 

 lead wire position retention. 

The pump stators must specifically be wound with the same gauge wire and install the 

same thermal fuses in an identical manner as the OEM in order to protect the pumps dry 

running and overheat performance as demonstrated in qualification tests. 

The pumps must retain all features designed by the OEM to provide explosion proof 

properties. These include but are not limited to: Bearing materials and clearances, 

Housing materials and thickness, size of vent and cooling holes and installation of flamearresting plates, and metal-to-metal faying surfaces. 

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CDCCL 28-2 - Twinjet Fuel Pump (Boost or Transfer) and Housing Assemblies 

(cont’d) 

The pump must retain all OEM features of the inlet housing shape and clearances and 

materials as well as the materials of the impellers (including the reprime impellers when 

installed). Non-sparking materials must be used where pump inlet surfaces might rub to 

prevent inlet ignition events. 

Pump volute design and inlet screens must be maintained as designed by Boeing and/or 

OEM. This is to prevent FOD ingestion. 

Connector detail design must continue to match connector explosion proof test results. 

The pump connector wire lead routing inside the pump housing must be installed so that it 

cannot contact the rotor and charge the rotor which could lead to an electrical arc between 

the inlet impeller and the housing. 

The electrical bonding paths from the motor housing to the inlet housing to the volute and 

to ground must be maintained. Changes to material coatings at motor housing joints, 

motor-to-volute interface, and volute-to-structure interface could defeat fault current 

bonding paths. 

Exposure of pump and volute’s aluminum components to mercury may result in material 

embrittlement, which could compromise critical design features of the pump or volute. 

All OEM design features, CMM instructions, or combinations of the two as applicable to 

a given pump model must be retained to prevent contact between the stator lead wire(s) 

and rotor assembly, which could result in an energized rotor condition. 

4. What is the specific Limitation? 

Any repair to the fuel pumps must be made in accordance with the OEM’s Component 

Maintenance Manuals (CMMs) listed below or an FAA approved service bulletin. 

Part Number(s) CMM CMM Revision 

(DC-9, MD-80, MD-90) 

65-5093-4 

65-5094-1 

65-5094-2 

65-5094-3 

65-5095-1 

65-5095-3 

28-20-1 6 

(DC-9, MD-80, MD-90) 

65-5107-1 

65-5107-2 

28-20-2 3 

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Part Number(s) CMM CMM Revision 

(DC-9, MD-80, MD-90) 

65-5095-2 

65-5095-4 

28-20-3 2 

(DC-9, MD-80, MD-90) 

398000-1 

398000-2 

399300-2 

399500-1 

702200-1 

702300-1 

28-20-6 6 

(717) 

398000-1 

398000-2 

399300-2 

399500-1 

28-20-6 6 

(DC-9, MD-80, MD-90, 717) 

RR12551A 

RR12552A 

28-20-03 6 

Any deviation from the OEM’s CMM must be justified by the modifier and approved by 

the FAA LA-ACO. 

Exposure of any pump or volute assembly or their subcomponents to mercury is 

prohibited. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-3 – Twinjet Fuel Pump Electrical Connector Wire/Conduit Assembly 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

The aircraft installed fuel pump electrical connector/wiring/conduit assembly located 

inside the fuel tanks, passing through the fuel tank bulkhead, terminating at an electrical 

terminal strip or connector which connects the fuel pump to the aircraft power system. 

This does not include wiring inside the fuel pump. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

1. Connector, Only P/N’s 14158-1 or 14158-2 can be used when rebuilding or repairing 

a pump conduit assembly for a DC-9. 

Only P/N 14158-2 can be used in MD-80s, MD-90s and 717s (used to maintain the 

explosion proof qualities when connected to the fuel pump connector). 

2. Assembly procedures for the wire harness/conduit assembly are to be used to 

maintain the design intent to prevent connector, wiring and conduit damage and/or 

failure inside the tank. 

4. What is the specific Limitation? 

Only connector P/N’s 14158-1 or 14158-2 can be used when rebuilding or repairing a 

pump conduit assembly for a DC-9. 

Only connector P/N 14158-2 can be used when rebuilding or repairing a pump conduit 

assembly for a MD-80, MD-90 or 717. 

Repairs to the fuel pump conduit/wire assembly must be done with the assembly removed 

from the aircraft and in accordance with DC-9, MD-80, MD-90, 717 Overhaul Manual 

chapter 28-20-7, Revision 6 or later dated May 15, 1999. 

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CDCCL 28-3 – Twinjet Fuel Pump Electrical Connector Wire/Conduit Assembly 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series Not all DC-9 aircraft were in compliance with this CDCCL at 

delivery. Boeing Service Bulletin DC9-28-26, Revision 1 dated 

4/21/1976 or later is effective for DC-9 Fuselage Number 1 

through Fuselage Number 764. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-4 – DC-9 Fuel Quantity Master Indicators 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

2. What part, LRU or system is the CDCCL levied against? 

All DC-9 airplanes which utilize the following fuel quantity gauging system (FQGS) 

components: 

 Master indicator P/N’s B118-244 and B118-264 for Goodrich/Simmonds/Liquidometer FQGS installations 

 Master indicator P/N’s 200-002-001 and 200-002-002 for Parker/Gull FQGS 

installations 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

FQGS master indicator maintenance procedures must be controlled to protect its internal 

electrical circuit integrity, limiting operational and failure conditions to a known set of 

results. 

4. What is the specific Limitation? 

Any repair to a FQGS master indicator must be made in accordance with the OEM’s 

Component Maintenance Manuals (CMMs) listed below or an FAA approved service 

bulletin. 

Part Number(s) CMM CMM Revision 

200-002-001 

and 

200-002-002 

28-40-14 5 

B118-244 28-41-41 4 

B118-264 28-41-11 B 

Any deviation from the OEM’s CMM must be justified by the modifier and approved by 

the FAA LA-ACO. 

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CDCCL 28-4 – DC-9 Fuel Quantity Master Indicators 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-5 – MD-80/MD-90 Fuel Quantity Standard Electronic Module 

1. What twinjet model does this CDCCL apply to? 

MD-80 Series 

MD-90 Series 

2. What part, LRU or system is the CDCCL levied against? 

Fuel quantity gauging system (FQGS) Standard Electronic Module (SEM). 

 SEM P/N’s 367-010-001, 367-010-002, 367-010-005, 367-010-006, 367-010-011 and 

367-010-012 for Parker/Gull FQGS installations 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

FQGS SEM maintenance procedures must be controlled to protect its internal electrical 

circuit integrity, limiting operational and failure conditions to a known set of results. 

4. What is the specific Limitation? 

Any repair to a FQGS SEM must be made in accordance with the OEM’s Component 

Maintenance Manuals (CMMs) listed below or an FAA approved service bulletin. 

Part Number(s) CMM CMM Revision 

(MD-80) 

367-010-001 

and 

367-010-002 

28-40-34 7 

(MD-80) 

367-010-005 

and 

367-010-006 

28-40-58 16 

(MD-80 and MD-90) 

367-010-011 

and 

367-010-012 

28-40-53 12 

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CDCCL 28-5 – MD-80/MD-90 Fuel Quantity Standard Electronic Module 

(cont’d) 

Any deviation from the OEM’s CMM must be justified by the modifier and approved by 

the FAA LA-ACO. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-6 – MD-80/MD-90/717 Fuel Quantity Standard Electronic Module 

1. What twinjet model does this CDCCL apply to? 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Fuel quantity gauging system (FQGS) Standard Electronic Module (SEM). 

 MD-80/MD-90 SEM P/N 367-100-001 and 367-100-002 for Parker FQGS installations 

 717 SEM P/N 367-200-101 for Parker FQGS installations 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

FQGS SEM maintenance procedures must be controlled to protect its internal electrical 

circuit integrity, limiting operational and failure conditions to a known set of results. 

4. What is the specific Limitation? 

Any repair to a FQGS SEM must be made in accordance with the OEM’s Component 

Maintenance Manuals (CMMs) listed below or an FAA approved service bulletin. 

Part Number(s) CMM CMM Revision 

(MD-80 and MD-90) 

367-100-001 

and 

367-100-002 

28-40-93 5 

(717) 

367-200-101 

28-40-99 3 

Any deviation from the OEM’s CMM must be justified by the modifier and approved by 

the FAA LA-ACO. 

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CDCCL 28-6 – MD-80/MD-90/717 Fuel Quantity Standard Electronic Module 

(cont’d) 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-7 – Twinjet Fuel Pump Connector 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the CDCCL levied against? 

Tank mounted electrically operated fuel pumps. Affected parts are: 

 Nash Fuel Pump part number 65-5093-4. 

 TRW / Argo-Tech Fuel Pump part number 398000-1 and 398000-2. 

 Lear-Romec Fuel Pump part numbers RR12551A and RR12559A. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

Proper torque of electrical connector to pump. An under torqued connector may leak fuel 

into the connector, or may back off and open the connector, leading to short circuits of 

the pump power wires and potentially an ignition source within the fuel tank. 

4. What is the specific Limitation? 

Inspection of the pump connector/torquing is to be witnessed by second individual every 

time the pump connector is installed. 

or if a second individual is not available:

An individual mechanic must double check the torque and confirm by applying a torque 

stripe to the connector every time a pump connector is installed.

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series All airplane type designs comply. 

MD-80 Series All airplane type designs comply. 

MD-90 Series All airplane type designs comply. 

717 Series All airplane type designs comply. 

6. When does this CDCCL become effective? 

This CDCCL becomes effective for all repairs performed after August 1, 2006. 

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CDCCL 28-8 – Twinjet Ground Fault Interrupter 

1. What twinjet model does this CDCCL apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

2. What part, LRU or system is the CDCCL levied against? 

Ground Fault Interrupter (GFI) installed on Auxiliary Fuel Tanks and MD-80/MD-90 

center fuel tanks pumps. 

3. What characteristic of the design configuration for this item must be retained under 

control of this Limitation, and why? 

The ground fault detection and interruption feature protects against electrical arc burnthrough fuel tank ignition source threats that may result from certain electrical failure 

modes of the fuel pump motor assembly and fuel pump housing electrical connector. 

4. What is the specific Limitation? 

Any replacement boost and transfer fuel pump ground fault interrupter must be a Boeing 

approved part for installation on the applicable model. 

5. Were all applicable aircraft in compliance with this CDCCL at delivery from the 

OEM? If not, is there an applicable Service Bulletin or Service Rework package 

required for some aircraft? 

DC-9 Series Service Bulletin DC9-28-218 Rev New or Later 

MD-80 Series Service Bulletin MD80-28-228 Rev New or Later 

MD-90 Series Service Bulletin MD90-28-013 Rev New or Later 

6. When does this CDCCL become effective? 

This CDCCL becomes effective after incorporation of Service Bulletins DC9-28-218, 

MD80-28-228, or MD90-28-013 

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Appendix C 

Airworthiness Limitation Instruction (ALIs) 
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TWINJET AIRWORTHINESS LIMITATION INSTRUCTIONS (ALI’s) 

For some twinjet system functions, compliance with SFAR 88 and Advisory Circular (AC) 

25.981-1C require inspections for certain design configurations, using AC 25-19 “Certification 

Maintenance Requirements (CMRs)” methodology as a guide. 

Similarly, Airworthiness Limitation Instruction (ALIs) are a means of detecting safety 

significant conditions, potentially making the airplane non-compliant with SFAR 88 and FAR 

25.981(b). When an ALI detects such a condition, maintenance action to correct it is required. 

The terms of the twinjet Type Certificate are only valid when associated checks specified by 

these ALIs are performed within the time intervals specified. ALIs are equivalent to one-star 

CMRs (per AC 25-19): The configuration control checks and intervals specified are mandatory 

and cannot be changed, escalated, or deleted without the approval of FAA Engineering of the 

Los Angeles Aircraft Certification Office (LA-ACO). 

Temporary deviations from the ALI intervals are permitted within the limitations of Appendix D. 

While each ALI is included in this report, it is required that each ALI also be included in an 

appropriate document where it will be visible to airline personnel; therefore each ALI must be 

included in each Operator's Maintenance Program. SFAR88 established requirements for ALIs; 

it includes an implementation schedule of changes to the operator’s maintenance program to 

manage compliance with these limitations and implementation of these checks. 

All maintenance and repair instructions provided by Boeing have been updated where required 

to ensure compatibility with these inspections. 
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Each ALI specified herein includes the name of the system in which the ALI is needed, and the 

following information: 

1. What model twinjet does this ALI apply to? 

2. What part, LRU or system is the ALI levied against? 

3. What part, LRU or system characteristic is being looked for? 

4. How is it found? 

5. What checks are to be performed? 

6. Is test equipment needed? 

7. What is the pass-fail criteria? 

8. What is the ALI accomplishment interval? 

9. When does this ALI become effective? 

Please report any negative inspection results to your local Boeing Field Service Representative. 

If the Boeing Field Service Representative is not available, you may send the report to: 

The Boeing Company 

3855 Lakewood Blvd. 

Long Beach, CA, USA 90846 

Attn: 

Manager - Avionics & Electrical Systems (Dept. L33) 

Service Engineering 

Technical Services & Modifications 

Mail Code: D800-0035 
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ALI 20-1 - Twinjet Fuel Pump and Auxiliary Hydraulic Pump Circuit Protection Devices 

Reset 

1. What twinjet model does this ALI apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

717 Series 

2. What part, LRU or system is the ALI levied against? 

All fuel pump and auxiliary hydraulic pump circuit protection devices, i.e. circuit 

breakers, ground fault interrupter, fault current detector, and fuse. 

3. What part, LRU or system characteristic is being looked for? 

This limitation prohibits the resetting of any tripped fuel pump and auxiliary hydraulic 

pump circuit protection devices until it has been determined it is safe to do so. 

4. How is it found? 

Tripped fuel pump and auxiliary hydraulic pump circuit protection devices will be 

reported by flight crew and will generate maintenance action. 

5. What checks are to be performed? 

Verify it is safe to reset the circuit protection device(s) by following the applicable OEM 

troubleshooting procedures. Fault(s) that resulted in circuit protection device trip must 

be isolated and corrected prior to reset if the fault(s) occurred inside the fuel tank or 

adjacent to any fuel tank wall. 

6. Is test equipment needed? 

Yes, standard electrical tools. 

7. What is the pass-fail criteria? 

Pass - It is safe to reset the circuit protection device(s) if the troubleshooting procedures 

are successfully completed, and problem has been corrected. 

Fail - It is not safe to reset the circuit protection device(s) if the troubleshooting 

procedures are not successfully completed. 

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ALI 20-1 - Twinjet Fuel Pump and Auxiliary Hydraulic Pump Circuit Protection Devices 

Reset 

(cont’d) 

8. What is the ALI accomplishment interval? 

There is no fixed inspection interval. This ALI applies only when the open circuit 

protection device condition occurs in service. 

9. When does this ALI become effective? 

August 2, 2006 

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ALI 20-2 – MD-80 Auxiliary Hydraulic Pump Power Feeder Wiring 

1. What twinjet model does this ALI apply to? 

 MD-80 Series 

2. What part, LRU or system is the ALI levied against? 

Auxiliary hydraulic pump power feeder wiring near the fuel tank. 

3. What part, LRU or system characteristic is being looked for? 

Physical separation of power feeder wiring from fuel tank walls. 

4. How is it found? 

Visual inspection. 

5. What checks are to be performed? 

(a) Verify that auxiliary hydraulic pump power feeders do not contact the fuel tank. 

(b) Verify that auxiliary hydraulic pump power feeders are properly installed in DMS 2109 

sleeving, per Standard Wiring Practices Manual (Boeing document number D6-82481), 

section 20-10-01, in the paragraph titled “Protection of Installed Wire Bundles”, over the 

entire harness length that is adjacent to the fuel tank. Additionally verify that the 

sleeving does not show signs of rubbing against fuel tank wall structure. 

6. Is test equipment needed? 

No. 
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ALI 20-2 – MD-80 Auxiliary Hydraulic Pump Power Feeder Wiring 

(cont’d) 

7. What is the pass-fail criteria? 

Pass - The auxiliary hydraulic pump power feeder harness does not contact or show signs 

of rubbing against the fuel tank wall, and DMS 2109 sleeving is properly installed 

per paragraph 5. 

Fail - The applicable length of auxiliary hydraulic pump power feeder harness shows 

signs of contact or rubbing against the fuel tank wall, or the DMS 2109 sleeving is 

not properly installed. 

8. What is the ALI accomplishment interval? 

At intervals prior to, but not to exceed, 5,000 flight hours. 

9. When does this ALI become effective? 

August 2, 2006 
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ALI 20-3 – MD-90 Auxiliary Hydraulic Pump Power Feeder Wiring 

1. What twinjet model does this ALI apply to? 

 MD-90 Series 

2. What part, LRU or system is the ALI levied against? 

Auxiliary hydraulic pump power feeder wiring near the fuel tank. 

3. What part, LRU or system characteristic is being looked for? 

Physical separation of power feeder wiring from fuel tank walls. 

4. How is it found? 

Visual inspection. 

5. What checks are to be performed? 

(a) Verify that auxiliary hydraulic pump power feeders do not contact the fuel tank. 

(b) Verify that auxiliary hydraulic pump power feeders are properly covered with a textile 

overbraid (outer layer) over the entire length that is adjacent to the fuel tank. 

Additionally, verify that the textile overbraid (outer layer) does not show signs of rubbing 

against fuel tank wall structure. 

NOTE: These power feeders are covered with a metallic inner layer and a textile 

overbraid outer layer.
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ALI 20-3 – MD--90 Auxiliary Hydraulic Pump Power Feeder Wiring 

(cont’d) 

6. Is test equipment needed? 

No. 

7. What is the pass-fail criteria? 

Pass - The auxiliary hydraulic pump power feeder harness does not contact or show signs 

of rubbing against the fuel tank wall, and the textile overbraid (outer layer) is 

properly installed per paragraph 5. 

Fail - The applicable length of auxiliary hydraulic pump power feeder harness shows 

signs of contact or rubbing against the fuel tank wall, or the textile overbraid (outer 

layer) is not properly installed. 

8. What is the ALI accomplishment interval? 

At intervals prior to, but not to exceed, 5,000 flight hours. 

9. When does this ALI become effective? 

August 2, 2006 
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ALI 28-1 - Twinjet Ground Fault Interrupter (GFI) Test 

1. What twinjet model does this ALI apply to? 

DC-9 Series 

MD-80 Series 

MD-90 Series 

2. What part, LRU or system is the ALI levied against? 

All Ground Fault Interrupters installed on MD-80/MD-90 center wing fuel tank and DC9/MD-80/MD-90 auxiliary fuel tank (if installed) fuel pump circuits 

3. What part, LRU or system characteristic is being looked for? 

The functionality of the ground fault interruption and indication features. 

4. How is it found? 

Functional Check of the GFI 

5. What checks are to be performed? 

1. Put the aircraft into the fuel pump operational/functional test condition per the 

AMM (Ref.DC-9 AMM 28-20-18, MD-80 AMM 28-20-07, MD-80 AMM 28-20-

18, or MD-90 AMM 28-20-00 ). 

2. Access applicable GFI to be tested. 

3. Turn on applicable fuel pump to be tested (Ref. DC-9 AMM 28-20-18, MD-80 

AMM 28-20-07, MD-80 AMM 28-20-18, or MD-90 AMM 28-20-00). 

4. Verify fuel pump being tested is functional (Ref. DC-9 AMM 28-20-18, MD-80 

AMM 28-20-07, MD-80 AMM 28-20-18, or MD-90 AMM 28-20-00). 

5. Press the TEST Pushbutton, located at the top of the GFI being tested and release 

and verify the RESET Indicator has popped up and the white band on the Indicator 

is visible. 

6. Verify fuel pump being tested is no longer functional, low fuel pressure indication 

should show for the applicable pump 

7. Turn off the fuel pump being tested 

8. To functionally reset the applicable fuel pump control GFI, press the RESET 

Indicator on the top of the GFI. 

9. Press the RESET Indicator. Verify the RESET Indicator remains depressed and the 

white band on the Indicator is no longer visible 

10. Turn on applicable fuel pump to be tested (Ref. DC-9 AMM 28-20-18, MD-80 

AMM 28-20-07, MD-80 AMM 28-20-18, or MD-90 AMM 28-20-00). 

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ALI 28-1 - Twinjet Ground Fault Interrupter Test (Contd)

11. Verify fuel pump being tested is functional (Ref. DC-9 AMM 28-20-18, MD-80 

AMM 28-20-07, MD-80 AMM 28-20-18, or MD-90 AMM 28-20-00). 

12. Repeat test on remaining GFIs. 

6. Is test equipment needed? 

No. 

7. What is the pass-fail criteria? 

Pass - The GFI de-energizes the pump and the RESET indicator pops up showing the 

white band. 

Fail - The GFI does not de-energize the pump or the RESET indicator does not pop up. 

8. What is the ALI accomplishment interval? 

At intervals prior to, but not to exceed, 4,000 flight hours. 

9. When does this ALI become effective? 

This ALI becomes effective after incorporation of Service Bulletins DC9-28-218, MD80-

28-228, or MD90-28-013 

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ALI 28-2 - Twinjet Auxiliary and Center Wing Tank Fuel Pump Low Pressure 

Indication System Test 

1. What twinjet model does this ALI apply to? 

DC-9 Series 

MD-90 Series 

2. What part, LRU or system is the ALI levied against? 

All fuel pump pressure indication systems installed for MD-90 Enhanced Flight 

Deck Configuration center wing fuel tanks and for DC-9 auxiliary fuel tanks (if 

installed). 

3. What part, LRU or system characteristic is being looked for? 

Wire and relay contact continuity check of the fuel pump low pressure indication 

system. 

4. How is it found? 

Electrical continuity checks of wiring and relay contacts. 

5. What checks are to be performed? 

General Set-Up and Access 

1. Put the aircraft into the fuel pump operational/functional test condition per the AMM 

(Ref.DC-9 AMM 28-20-7, or MD-90 AMM 28-44-00). 

2. Access applicable areas requiring temporary disconnection of wires 

3. For DC-9/C-9 checks, verify airplane Ground Control system is configured to show 

an airplane “on-ground” status. 

 

DC-9/C-9 – Forward and Aft Auxiliary Fuel Tanks with Direct Engine Feed 

Boost Pumps 

WARNING: Power to the relay is needed for the test. Pulling associated 

breaker to remove and reattach the wire may be necessary. 

4. Disconnect wire Q468F20 from the A1 terminal of Relay R2-1511 

CAUTION: The relay A1 terminal will be powered with 28VDC while the 

 fuel pump is commanded ON. 

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ALI 28-2 - Twinjet Auxiliary and Center Wing Tank Fuel Pump Low Pressure 

Indication System Test (Cont’d) 

5. On the flight deck overhead panel, switch forward auxiliary fuel tank boost pump A 

to ON 

6. Verify the applicable auxiliary fuel tank pump low pressure light on the OAP 

illuminates momentarily 

7. On the flight deck overhead panel, switch forward auxiliary fuel tank boost pump A 

to OFF 

8. Reconnect wire Q468F20 to the A1 terminal of Relay R2-1511 

9. Repeat steps 4 thru 8 substituting the wires, relay and switch found in the table below 

Wire Relay Switch 

Q468G20 R2-1512 FWD AUX BOOST PUMP B 

Q472F20 R2-1513 AFT AUX BOOST PUMP A 

Q472G20 R2-1514 AFT AUX BOOST PUMP B 

DC-9/C-9 – Forward Auxiliary Fuel Tank with Single Transfer Fuel Pump 

Do steps 4 thru 8 of the DC-9/C-9 – Forward and Aft Auxiliary Fuel Tanks 

with Direct Engine Feed Boost Pumps substituting the wires, relay and switch 

found in the table below. 

Wire Relay Switch 

Q478A20 R2-1511 FWD AUX BOOST PUMP 

DC-9/C-9 – Forward Auxiliary Fuel Tank with Single Transfer Fuel Pump and 

Aft Auxiliary Fuel Tank with Two Transfer Pumps

Do steps 4 thru 8 of the DC-9/C-9 – Forward and Aft Auxiliary Fuel Tanks 

with Direct Engine Feed Boost Pumps substituting the wires, relay and switch 

found in the table below. 

Wire Relay Switch 

Q482E20 R2-1511 FWD AUX BOOST PUMP 

Q486B20 R2-1512 AFT AUX fuel NORM Tank Boost Pump* 

Q486C20 R2-1513 AFT AUX ALT Boost Pump 

DC-9/C-9 – Forward Auxiliary Fuel Tank with Two Transfer Pumps

Do steps 4 thru 8 of the DC-9/C-9 – Forward and Aft Auxiliary Fuel Tanks 

with Direct Engine Feed Boost Pumps substituting the wires, relay and switch 

found in the table below. 

Wire Relay Switch 

Q482E20 R2-1511 FWD AUX fuel NORM Tank Boost Pump 

Q482D20 R2-1512 FWD AUX ALT Boost Pump 

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ALI 28-2 - Twinjet Auxiliary and Center Wing Tank Fuel Pump Low Pressure 

Indication System Test (Cont’d) 

MD-90 Enhanced Flight Deck Configuration Center Wing Tank Fuel Pumps

Verify open circuit exists for the circuit running through contacts 12/13 in relay R2-

1494 and contacts D2/D3 in relay R2-583 for center tank forward pump and contacts 

12/13 in relay R2-1495 and contacts D2/D3 in relay R2-582 for center tank aft pump 

with applicable fuel pump commanded ON: 

To evaluate the Center FWD Boost Pump, access VIA R-T-S Discrete Status Screens, 

Insert A, and do the following: 

1) Put the Center FWD Boost Pump to ON and look at the state of Pin G8. 

(a) Verify O is shown for VIA-1. 

(b) Verify O is shown for VIA-2. 

(c) Put the Center FWD Boost Pump to OFF. 

To evaluate the Center AFT Boost Pump, access VIA R-T-S Discrete Status Screens, 

Insert D, and do the following: 

1) Put the Center AFT Boost Pump to ON and look at the state of Pin G8. 

(a) Verify O is shown for VIA-1 

(b) Verify O is shown for VIA-2 

(c) Put the Center AFT Boost Pump to OFF. 

6. Is test equipment needed? 

Electrical continuity test equipment 

7. What is the pass-fail criteria? 

C-9/DC-9 Auxiliary Fuel Tank Fuel Pumps

Pass - auxiliary fuel tank pump low pressure light on the OAP illuminates 

momentarily 

Fail - auxiliary fuel tank pump low pressure light on the OAP does not 

illuminate momentarily 

MD-90 Enhanced Flight Deck Configuration Center Wing Tank Fuel Pumps

Pass - Open circuit exists for pin A-G8, CTR FWD FUEL PMP RELAY in VIA-1 

and VIA-2 R-T-S Discrete Status Screens, Insert A with the center tank 

forward pump commanded ON;

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ALI 28-2 - Twinjet Auxiliary and Center Wing Tank Fuel Pump Low Pressure 

Indication System Test (Cont’d)

 AND open circuit exists for pin D-G8, CTR AFT FUEL PMP RELAY in VIA-1 

and VIA-2 R-T-S Discrete Status Screens, Insert D with the center tank aft pump 

commanded ON 

Fail - Ground circuit exists for A-G8, CTR FWD FUEL PMP RELAY in VIA-1 or VIA2 R-T-S Discrete Status Screens, Insert A with the center tank forward pump 

commanded ON; 

OR ground circuit exists for pin D-G8, CTR AFT FUEL PMP RELAY in VIA-1 

or VIA-2 R-T-S Discrete Status Screens, Insert D with the center tank aft pump 

commanded ON 

8. What is the ALI accomplishment interval? 

At intervals prior to, but not to exceed, 4,000 flight hours. 

9. When does this ALI become effective? 

This ALI becomes effective after incorporation of Service Bulletins DC9-28-218 or 

MD90-28-013 as applicable

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APPENDIX D - SHORT-TERM EXTENSIONS 

Since SCIs and ALIs are based on analysis using AC 25-19 methodology, temporary deviation 

from the SCI/ALI intervals in this document are permitted in accordance with the limitations 

within this Appendix. Such an extension should be handled similar to the operator's Approved 

Short-term Escalation Procedures. Each time an operator uses such a temporary SCI/ALI 

interval extension, the operator must notify their local regulatory authority (e.g. Principle 

Maintenance Inspector) as soon as practicable that a short-term extension has been utilized. 

Any deviation beyond the limitations within this Appendix requires approval of the responsible 

Los Angeles Aircraft Certification Office (LA-ACO), prior to its use. Extensions within the 

limitations of this Appendix have LA-ACO approval. 

 o Deviations are permitted only for an exceptional, short-term extension of an individual 

SCI/ALI for a specific airplane. 

 o Repeated use of extensions, either on the same airplane or on similar airplanes in the 

operator's fleet, must not be used as a substitute for good management practices. 

 o Repeated extensions for the same SCI/ALI are not allowed. 

 o Extensions may not be used for fleet SCI/ALI escalation or extension. 

 o Short-term is defined as 10% of the SCI/ALI interval, up to a maximum of 30 days; this 

is applicable to each SCI/ALI in this report unless specifically defined in the applicable 

SCI/ALI. 

 o The purpose of this Appendix is to allow very short-term "get home" capability in those 

exceptional cases where uncontrollable or unexpected events ground an airplane with 

insufficient time remaining on a SCI/ALI. It is intended that use of such short-term 

exceptional extensions be rare. If they are desired more often at an airline, it is evidence 

of trouble in maintenance planning. It is not allowed to repetitively use the authority of 

this Appendix for relief for such a situation.