TITLE: ELECTRICAL POWER - INSULATION RESISTANCE TESTING OF CERAMIC

TERMINAL BLOCKS.

REVISION: 1 DATE: 02-OCT-2012

ACTION :

FOR THOSE OPERATORS THAT HAVE PREVIOUSLY RECEIVED THIS BULLETIN:

1.Remove and destroy existing Service Bulletin complete at Initial

Issue.

2.Insert Service Bulletin complete at Revision No. 1.

INCORPORATION OF THIS REVISION DOES NOT REQUIRE REWORK BY

OPERATORS WHO HAVE EMBODIED THIS INSPECTION SERVICE BULLETIN.

OVERVIEW OF CHANGE :

(1) The correction of typographical errors.

(2) Note added to explain the course of action prior to replacing

terminal blocks.

DETAILS OF CHANGE:

Terminals G8, G9 and G10 - Fire Extinguishers, table -

Typographical error corrected. Grid Ref/Ident D20/WB1 revised to

C20/WB1.

Para. 1.J. - WM 26-11-04 added to references.

Para. 2.C. - WM 26-11-04 added to reference.

Para. 2.E. - Typographical error corrected. Reference to WM

26-11-04 revised to WM 26-21-04.

Para. 2.G. - Remove / install instructions for ceramic terminal

blocks added.

Appendix 1, 2, 3, 4 - Note added after para.(4).

Appendix 4, Para.7. - Typographical error corrected. Para.5 added.

Appendix 5, Paras.B.(1) and C.(1) Continued airworthiness,

reference to Para 2.G. added.

BAE SYSTEMS (Operations) Limited, Prestwick International Airport, Ayrshire,

KA9 2RW, Scotland.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

TRANSMITTAL FOR INSPECTION SERVICE BULLETIN REVISION

SERVICE BULLETIN No.ISB. 24-143

DATE: 26-SEP-2011

Date: 26-SEP-2011 REVISION TRANSMITTAL SHEET

ISB. 24-143

Revision: 1 02-OCT-2012 Page 1 of 2

Printed in England
This Page Is Intentionally Left Blank.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

TRANSMITTAL FOR INSPECTION SERVICE BULLETIN REVISION

SERVICE BULLETIN No.ISB. 24-143

Date: 26-SEP-2011 REVISION TRANSMITTAL SHEET

ISB. 24-143

Revision: 1 02-OCT-2012 Page 2 of 2

Printed in England
TITLE: ELECTRICAL POWER - INSULATION RESISTANCE TESTING OF CERAMIC

TERMINAL BLOCKS.

1.Planning information

A.Effectivity

(1) Aircraft

Aircraft affected by this inspection are defined below,

providing modification HCM01693A has been embodied:-

BAe 146 301 Series

All BAe 146 100, 200, 300 Series

All AVRO 146-RJ70, RJ85, RJ100 Series

Check the aircraft technical records for accomplishment of

this inspection and the modification stated above before

actioning this Inspection Service Bulletin.

B.Reason

This Inspection Service Bulletin (ISB) is to confirm the integrity

of the ceramic terminal blocks, which were introduced by

modification HCM01693A during the period 2002 to 2004.

C.Description

This ISB checks the terminal blocks on the whole BAe 146 and AVRO

146-RJ fleet.

This ISB details a one-off insulation resistance test of the

ten-way ceramic Terminal Block G located on each engine cowling

(zones 412-00-00, 422-00-00, 432-00-00 and 442-00-00) (Ref. Table

1).

BAE SYSTEMS (Operations) Limited, Prestwick International Airport, Ayrshire,

KA9 2RW, Scotland.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 1 of 30

Printed in England
Table 1.

Terminal Block G

TERMINAL CABLE TYPE SYSTEM WIRING MANUAL REF.

1 ASK ENG. FIRE WNG. LOOP B 26-11-07

2 ASK ENG. FIRE WNG. LOOP B 26-11-07

3 ANA ENG. AND INTAKE ANT-ICE 75-10-01

4 ASK ENG. FIRE WNG. LOOP A 26-11-01

5 ASK ENG. FIRE WNG. LOOP A 26-11-01

6 - SPARE - - -

7 - SPARE - - -

8 ASK ENG. FIRE EXTINGUISH 26-21-01

26-21-04

9 ASK ENG. FIRE EXTINGUISH 26-21-01

26-21-04

10 ASK ENG. FIRE EXTINGUISH 26-21-01

26-21-04

D.Compliance

The technical content of this service bulletin is the subject of

EASA AIRWORTHINESS DIRECTIVE (AD) No. 2012-0040 consultation.

The inspections detailed in this Bulletin should be carried out at

the next ’C’ check or within 18 months of the receipt of this

bulletin, whichever is sooner.

E.Approval

The technical information contained in this document has been

approved under the authority of EASA Part 21 Approval No.

EASA.21J.047.

The technical information contained in this document has been

approved under the authority of UK CAA Approval Reference:

AD/1852/05.

F.Manpower

To test as defined in para. 2 - 10 man-hours.

This man-hour estimate does not include time for gaining access

to, or cleaning, the inspection area.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 2 of 30

Printed in England
G.Materials - cost and availability

Not applicable.

H.Tooling - cost and availability

Not applicable.

I.Weight and balance

No Effect.

J.References

Aircraft Maintenance Manual 06-20-00, 06-40-00, 26-11-00,

26-20-00, 30-21-17 and 71-10-11.

Wiring Manual 26-11-01, 26-11-04, 26-11-07, 26-21-01, 26-21-04,

and 75-10-01.

K.Publications affected

None.

L.Electrical load data

Not applicable.

M.Software Accomplishment Summary

Not applicable.

N.Aircraft Noise Levels

Not applicable.

INSPECTION SERVICE BULLETIN

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 3 of 30

Printed in England
This Page Is Intentionally Left Blank.

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 4 of 30

Printed in England
2.Accomplishment instructions

A.General

(1) The following abbreviations are used within this document :-

AMM - Aircraft Maintenance Manual

WM - Wiring Manual

(2) Observe all WARNINGS and CAUTIONS appearing in the Aircraft

Maintenance Manual (AMM) referred to in this Service

Bulletin.

B.Preparation

(1) Refer to AMM 06-20-00 and AMM 06-40-00 and gain access to the

Flight Deck, the Electrical Equipment Bay and the Cowling of

Engines 1, 2, 3 and 4.

(2) Open, safety and tag the following circuit breaker(s) :-

Terminals G1 and G2 - Engine Fire Warning Loop B (if

applicable)

PANEL LABEL/SERVICE GRID REF/

IDENT

211-50-30 ENG 1 LOOP B F16/1WA11

211-50-30 ENG 2 LOOP B F17/2WA11

211-50-30 ENG 3 LOOP B F18/3WA11

211-50-30 ENG 4 LOOP B F19/4WA11

211-50-30 LOOP B WARN + TEST E22/WA1

Terminals G4 and G5 - Engine Fire Warning Loop A

PANEL LABEL/SERVICE GRID REF/

IDENT

211-50-30 ENG 1 LOOP A E16/1WA1

211-50-30 ENG 2 LOOP A E17/2WA1

211-50-30 ENG 3 LOOP A E18/3WA1

211-50-30 ENG 4 LOOP A E19/4WA1

211-50-30 LOOP A WARN + TEST E20/WA2

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 5 of 30

Printed in England
Terminals G8, G9 and G10 - Fire Extinguishers

PANEL LABEL/SERVICE GRID REF/

IDENT

211-50-30 ENG 1 EXT NO. 1 C16/1WB8

211-50-30 ENG 1 EXT NO. 2 D16/1WB9

211-50-30 ENG 2 EXT NO. 1 C17/2WB8

211-50-30 ENG 2 EXT NO. 2 D17/2WB9

211-50-30 ENG 3 EXT NO. 1 C18/3WB8

211-50-30 ENG 3 EXT NO. 2 D18/3WB9

211-50-30 ENG 4 EXT NO. 1 C19/4WB8

211-50-30 ENG 4 EXT NO. 2 D19/4WB9

211-50-30 EXT NO. 2 USED ANNUNCIATOR D20/WB1

211-50-30 EXT NO. 1 AND APU USED ANNUNCIATOR C20/WB1

Terminals G3 - Engine and Intake Antice Valves

PANEL LABEL/SERVICE GRID REF/

IDENT

131-11-00 ENG 1 A/ICE VALVE M9/1HK2

131-12-00 ENG 2 A/ICE VALVE M23/2HK2

131-11-00 ENG 3 A/ICE VALVE N9/3HK2

131-12-00 ENG 4 A/ICE VALVE N23/4HK2

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 6 of 30

Printed in England
C.Test - Terminals G1 and G2

Refer to WM 26-11-04 and WM 26-11-07 - Engine Fire Warning Loop B

(if applicable).

Engine 1

(1) Disconnect items as follows:-

(a) On panel 412-00-00 disconnect plug WA12P.

(b) On panel 413-00-00 disconnect plug WA13P.

(c) On panel 131-13-00 unrack Fire Warning Loop B PCB WA4.

(2) Test

(a) Do an insulation resistance test of terminals G1 and G2

(Ref. Appendix 1 ).

Engine 2

(3) Disconnect items as follows:-

(a) On panel 422-00-00 disconnect plug WA12P.

(b) On panel 423-00-00 disconnect plug WA13P.

(c) On panel 131-13-00 unrack Fire Warning Loop B PCB WA4.

(4) Repeat para.2.C.(2) for Engine 2.

Engine 3

(5) Disconnect items as follows:-

(a) On panel 432-00-00 disconnect plug WA12P.

(b) On panel 433-00-00 disconnect plug WA13P.

(c) On panel 131-13-00 unrack Fire Warning Loop B PCB WA4.

(6) Repeat para.2.C.(2) for Engine 3.

Engine 4

(7) Disconnect items as follows:-

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 7 of 30

Printed in England
(a) On panel 442-00-00 disconnect plug WA12P.

(b) On panel 443-00-00 disconnect plug WA13P.

(c) On panel 131-13-00 unrack Fire Warning Loop B PCB WA4.

(8) Repeat para.2.C.(2) for Engine 4.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 8 of 30

Printed in England
D.Test - Terminals G4 and G5

Refer to WM 26-11-01 - Engine Fire Warning Loop A.

Engine 1

(1) Disconnect items as follows:-

(a) On panel 412-00-00 disconnect plug WA8P.

(b) On panel 413-00-00 disconnect plug WA9P.

(c) On panel 131-13-00 unrack Fire Warning Loop A PCB WA3.

(2) Test

(a) Do an insulation resistance test of terminals G4 and G5

(Ref. Appendix 2 ).

Engine 2

(3) Disconnect items as follows:-

(a) On panel 422-00-00 disconnect plug WA8P.

(b) On panel 423-00-00 disconnect plug WA9P.

(c) On panel 131-13-00 unrack Fire Warning Loop A PCB WA3.

(4) Repeat para.2.D.(2) for Engine 2.

Engine 3

(5) Disconnect items as follows:-

(a) On panel 432-00-00 disconnect plug WA8P.

(b) On panel 433-00-00 disconnect plug WA9P.

(c) On panel 131-13-00 unrack Fire Warning Loop A PCB WA3.

(6) Repeat para.2.D.(2) for Engine 3.

Engine 4

(7) Disconnect items as follows:-

(a) On panel 442-00-00 disconnect plug WA8P.

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Revision: 1 02-OCT-2012 Page 9 of 30

Printed in England
(b) On panel 443-00-00 disconnect plug WA9P.

(c) On panel 131-13-00 unrack Fire Warning Loop A PCB WA3.

(8) Repeat para.2.D.(2) for Engine 4.

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BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 10 of 30

Printed in England
E.Test - Terminals G8, G9 and G10

Refer to WM 26-21-01 - Engine 1 and 2 Fire Extinguishers, and WM

26-21-04 - Engine 3 and 4 Fire Extinguishers.

Engine 1

(1) Disconnect items as follows:-

(a) On panel 412-00-00 disconnect plug PF.

(b) On panel 131-13-00 unrack Type 3 Signal Conditioning PCB

WB4.

(2) Test

(a) Identify pins 2, 10, 12 and 14 on plug PF.

(b) Do an insulation resistance test of terminals G8, G9 and

G10 (Ref. Appendix 3 ).

Engine 2

(3) Disconnect items as follows:-

(a) On panel 422-00-00 disconnect plug PF.

(b) On panel 131-13-00 unrack Type 3 Signal Conditioning PCB

WB4.

(4) Repeat para.2.E.(2) for Engine 2.

Engine 3

(5) Disconnect items as follows:-

(a) On panel 432-00-00 disconnect plug PF.

(b) On panel 131-13-00 unrack Type 3 Signal Conditioning PCB

WB4.

(6) Repeat para.2.E.(2) for Engine 3.

Engine 4

(7) Disconnect items as follows:-

(a) On panel 442-00-00 disconnect plug PF.

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BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 11 of 30

Printed in England
(b) On panel 131-13-00 unrack Type 3 Signal Conditioning PCB

WB4.

(8) Repeat para.2.E.(2) for Engine 4.

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 12 of 30

Printed in England
F.Test - Terminal G3

Refer to WM 75-10-01 - Engine and Intake Anti Ice System.

Engine 1

(1) Disconnect items as follows:-

(a) On panel 412-00-00 disconnect plugs PF and P2.

(b) On panel 131-11-00 remove Auto Bleed On Start Relay 1HK1.

(2) Test

(a) Do an insulation resistance test of terminal G3 (Ref.

Appendix 4 ).

Engine 2

(3) Disconnect items as follows:-

(a) On panel 422-00-00 disconnect plugs PF and P2.

(b) On panel 131-11-00 remove Auto Bleed On Start Relay 2HK1.

(4) Repeat Appendix 1 para.1.A.(4) for Engine 2.

Engine 3

(5) Disconnect items as follows:-

(a) On panel 432-00-00 disconnect plugs PF and P2.

(b) On panel 131-12-00 remove Auto Bleed On Start Relay 3HK1.

(6) Repeat Appendix 1 para.1.A.(4) for Engine 3.

Engine 4

(7) Disconnect items as follows:-

(a) On panel 442-00-00 disconnect plugs PF and P2.

(b) On panel 131-12-00 remove Auto Bleed On Start Relay 4HK1.

(8) Repeat Appendix 1 para.1.A.(4) for Engine 4.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 13 of 30

Printed in England
G.Removal/Installation of Ceramic Terminal Blocks

NOTE: The following information is provided to Operators to permit

continued operation of the aircraft pending receipt of a

formal revision to AMM Chapter 71-10-11.

Refer to Appendix 1 para.1.A.(4) , Appendix 2 para.1.A.(4) ,

Appendix 3 para.1.A.(4) and Appendix 4 para.1.A.(4)

(1) To gain access to the G terminal block which is located on

the right hand side of the shoulder cowl (looking forward)

directly above the engine, it will be necessary to remove /

lower the relevant engine for access. Refer to AMM 71-00-00,

for removal / lowering of relevant engine.

(2) Refer to relevant existing wiring diagram in Table 2. Remove

and identify existing wires from terminal block G.

Table 2.

Wiring Manual References

REFERENCE TITLE

WM 26-11-01 Fig 1 ENGINE FIRE WARNING LOOP A

WN 26-11-01 Fig 2 ENGINE FIRE WARNING LOOP A

WM 26-11-04 Fig 1 ENGINE FIRE WARNING LOOP B

WM 26-11-07 Fig 1 ENGINE FIRE WARNING LOOP B

WM 26-21-01 Fig 1 ENGINE 1 AND 2 FIRE EXTINGUISHER

WM 26-21-04 Fig 1 ENGINE 3 AND 4 FIRE EXTINGUISHER

WM 75-10-01 Fig 1 ENGINE AND INTAKE ANTI ICE SYSTEM

WM 75-10-01 Fig 2 ENGINE AND INTAKE ANTI ICE SYSTEM

WM 75-10-01 Fig 3 ENGINE AND INTAKE ANTI ICE SYSTEM

WM 75-10-01 Fig 4 ENGINE AND INTAKE ANTI ICE SYSTEM

(3) Remove and retain existing attaching parts and remove

terminal block G.

(4) Position silicone strip between mounting plate and new

terminal block.

NOTE: Under no circumstances may the new ceramic terminal

block be modified.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 14 of 30

Printed in England
There should be no damage to the terminal block. Minor

chipping to the corners of the block may be acceptable

providing it does not constitute a crack in the material

or reduce the profile of the barriers between the

terminals.

(5) Install new terminal block using retained existing attaching

parts. Install washers under screw heads and nuts.

NOTE: It is essential that the terminal block screws have

adequate clearance with holes in the mounting plate and

that they do not bind on the mounting plate when

tightened.

(a) Progressively and carefully torque load each screw,

alternating between one and the other, until a torque of 9

lb.in. is achieved.

(b) Ensure adequate clearance of no less than 0.10 inches

between terminal block and attaching parts, and aircraft

structure / wiring. Adjust cable positions as required gain

clearance.

(6) Refer to relevant existing wiring diagram in Table 2. Install

existing wires and new terminal spacers to terminal block G.

(a) Torque terminals to 9 lb.in.

(7) Refer to AMM 71-00-00. Install relevant engine.

(a) Ensure adequate clearance of no less than 0.10 inches

between terminal block and wiring, and engine casing.

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BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 15 of 30

Printed in England
H.System Testing

(1) Remove safety clips and tags and close the circuit breakers

previously opened.

(2) Refer to AMM 26-11-00, page block 501 and do an Operational

Test of the Fire Detection System.

(3) Refer to AMM 26-20-00, page block 501 and do a Functional

Test of the Fire Extinguishing and Cartridge Firing Unit

System.

(4) Refer to AMM 30-21-17, page block 201 and do a test of the

Engine Intake Anti-icing Valves.

I.Close up

(1) Make certain work area is clean, and clear of tools and

miscellaneous equipment.

(2) Close all panels and doors previously opened for access.

J.Documentation

(1) Complete a copy of the Test Results (Appendices 1 to 4

inclusive) and the Inspection Report (Appendix 6) attached to

this Inspection Service Bulletin and return by fax or mail.

OR

Return all Test Results and Inspection Report details via

e-mail to

raengliaison@baesystems.com

K.Terminating action

(1) None.

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 16 of 30

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3.Material information

None.

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Date: 26-SEP-2011 ISB. 24-143

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 18 of 30

Printed in England
APPENDIX 1

1.TEST RESULTS

A.Terminals G1 and G2 - Engine Fire Warning Loop B (if applicable)

(1) Follow the instructions in para.2.C

(2) Use an approved insulation tester set at the range 250 V.

(3) Connect the insulation tester as follows and record the

measured results.

Engine No. 1

At connector WA12P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA13P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 2

At connector WA12P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA13P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 3

At connector WA12P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

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BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 19 of 30

Printed in England
At connector WA13P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 4

At connector WA12P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA13P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

(4) If any value obtained is less than 50 Mohms replace Terminal

Block G.

NOTE: If any value obtained is less than 50 Mohms then the

ultimate course of action is to replace terminal Block

G. However, it should be recognized that this test also

includes a check of the wiring to the terminal block G.

Therefore, it may be pertinent to check the cable looms

first just in case they are the source of the low

resistance. Only when that avenue has been exhausted

should the replacement of the terminal block itself be

contemplated. Thus it is just possible that this course

of action might avoid a lot of additional and

unnecessary work.

(5) Reconnect all items previously disconnected.

(6) Send the results to BAE SYSTEMS (Ref. Appendix 6).

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 20 of 30

Printed in England
APPENDIX 2

1.TEST RESULTS

A.Terminals G4 and G5 - Engine Fire Warning Loop A

(1) Follow the instructions in para.2.D

(2) Use an approved insulation tester set at the range 250 V.

(3) Connect the insulation tester as follows and record the

measured results.

Engine No. 1

At connector WA8P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA9P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 2

At connector WA8P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA9P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 3

At connector WA8P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

INSPECTION SERVICE BULLETIN

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Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 21 of 30

Printed in England
At connector WA9P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

Engine No. 4

At connector WA8P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

At connector WA9P Measure between pin A and ground ......................

Measure between pin B and ground ......................

Measure between pin A and pin B ......................

(4) If any value obtained is less than 50 Mohms replace Terminal

Block G.

NOTE: If any value obtained is less than 50 Mohms then the

ultimate course of action is to replace terminal Block

G. However, it should be recognized that this test also

includes a check of the wiring to the terminal block G.

Therefore, it may be pertinent to check the cable looms

first just in case they are the source of the low

resistance. Only when that avenue has been exhausted

should the replacement of the terminal block itself be

contemplated. Thus it is just possible that this course

of action might avoid a lot of additional and

unnecessary work.

(5) Reconnect all items previously disconnected.

(6) Send the results to BAE SYSTEMS (Ref. Appendix 6).

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 22 of 30

Printed in England
APPENDIX 3

1.TEST RESULTS

A.Terminals G8, G9 and G10 - Fire Extinguishers

(1) Follow the instructions in para.2.E.

(2) Use an approved insulation tester set at the range 250 V.

(3) Connect the insulation tester as follows and record the

measured results.

Engine No. 1

At connector PF Measure between pin 12 and ground ......................

Measure between pin 14 and ground ......................

Measure between pin 12 and pin 2 ......................

Measure between pin 14 and pin 10 ......................

Measure between pin 14 and pin 12 ......................

Engine No. 2

At connector PF Measure between pin 12 and ground ......................

Measure between pin 14 and ground ......................

Measure between pin 12 and pin 2 ......................

Measure between pin 14 and pin 10 ......................

Measure between pin 14 and pin 12 ......................

Engine No. 3

At connector PF Measure between pin 12 and ground ......................

Measure between pin 14 and ground ......................

Measure between pin 12 and pin 2 ......................

Measure between pin 14 and pin 10 ......................

Measure between pin 14 and pin 12 ......................

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Engine No. 4

At connector PF Measure between pin 12 and ground ......................

Measure between pin 14 and ground ......................

Measure between pin 12 and pin 2 ......................

Measure between pin 14 and pin 10 ......................

Measure between pin 14 and pin 12 ......................

(4) If any value obtained is less than 50 Mohms replace Terminal

Block G.

NOTE: If any value obtained is less than 50 Mohms then the

ultimate course of action is to replace terminal Block

G. However, it should be recognized that this test also

includes a check of the wiring to the terminal block G.

Therefore, it may be pertinent to check the cable looms

first just in case they are the source of the low

resistance. Only when that avenue has been exhausted

should the replacement of the terminal block itself be

contemplated. Thus it is just possible that this course

of action might avoid a lot of additional and

unnecessary work.

(5) Reconnect all items previously disconnected.

(6) Send the results to BAE SYSTEMS (Ref. Appendix 6).

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 24 of 30

Printed in England
APPENDIX 4

1.TEST RESULTS

A.Terminal G3 - Engine and Intake Antice Valves

(1) Follow the instructions in para.2.F.

(2) Use an approved insulation tester set at the range 250 V.

(3) Connect the insulation tester as follows and record the

measured results.

Engine No. 1

At connector PF Measure between pin 4 and ground ......................

Engine No. 2

At connector PF Measure between pin 4 and ground ......................

Engine No. 3

At connector PF Measure between pin 4 and ground ......................

Engine No. 4

At connector PF Measure between pin 4 and ground ......................

(4) If any value obtained is less than 50 Mohms replace Terminal

Block G.

NOTE: If any value obtained is less than 50 Mohms then the

ultimate course of action is to replace terminal Block

G. However, it should be recognized that this test also

includes a check of the wiring to the terminal block G.

Therefore, it may be pertinent to check the cable looms

first just in case they are the source of the low

resistance. Only when that avenue has been exhausted

should the replacement of the terminal block itself be

contemplated. Thus it is just possible that this course

of action might avoid a lot of additional and

unnecessary work.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 25 of 30

Printed in England
(5) To assist BAE SYSTEMS in product improvement, please record

the finish of any terminal blocks removed.

Record the results by ticking the appropriate item for each

engine.

Engine No. 1 VARNISHED..... or PURE-WHITE.....

Engine No. 2 VARNISHED..... or PURE-WHITE.....

Engine No. 3 VARNISHED..... or PURE-WHITE.....

Engine No. 4 VARNISHED..... or PURE-WHITE.....

(6) Reconnect all items previously disconnected.

(7) Visually examine each ceramic terminal block in situ to

determine if the unit under test has either, ’varnished’

appearance or else it has the later, pure-white finish.

Record the results by ticking the appropriate item for each

engine.

Engine No. 1 VARNISHED..... or PURE-WHITE.....

Engine No. 2 VARNISHED..... or PURE-WHITE.....

Engine No. 3 VARNISHED..... or PURE-WHITE.....

Engine No. 4 VARNISHED..... or PURE-WHITE.....

(8) Send the results to BAE SYSTEMS (Ref. Appendix 6).

(9) When all insulation testing has been completed, perform the

System Tests as described in para.2.H.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 26 of 30

Printed in England
APPENDIX 5

1.CONTINUED AIRWORTHINESS INSTRUCTIONS

(1) The following information is provided to Operators to permit

continued operation of the aircraft pending receipt of a

formal revision to the relevant aircraft manuals.

A.Scheduled Maintenance

(1) The MRBR and MPD will be reviewed for inclusion of a

scheduled task.

B.Removal Procedures

(1) Refer to para.2.G of this service bulletin for instructions

for removal of terminal blocks.

C.Installation Procedures

(1) Refer to para.2.G of this service bulletin for instructions

for installation of terminal blocks.

D.Inspection Procedures

(1) Refer to para.2.C, para.2.D, para.2.E and para.2.F of this

Inspection Service Bulletin.

E.Test Procedures

(1) Refer to para.2.H of this Inspection Service Bulletin.

F.Troubleshooting

(1) Refer to the Wiring Manuals listed in para.1.J of this

Service Bulletin.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 27 of 30

Printed in England
This Page Is Intentionally Left Blank.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 28 of 30

Printed in England
APPENDIX 6

1.INSPECTION REPORT

A.Complete and return this form as detailed

OPERATOR:

AIRCRAFT REGISTRATION:

CONSTRUCTORS NUMBER:

FLIGHT HOURS:

LANDINGS:

DATE INSPECTION PERFORMED:

FINDINGS:

To: Customer Technical Support (Building 37),

BAE SYSTEMS (Operations) Limited,

Prestwick International Airport,

Ayrshire,

KA9 2RW,

Scotland.

Fax + 44 (0) 1292 675432

e-mail raengliaison@baesystems.com

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 29 of 30

Printed in England
This Page Is Intentionally Left Blank.

INSPECTION SERVICE BULLETIN

BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143

Revision: 1 02-OCT-2012 Page 30 of 30

Printed in England