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 EnglandThis 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 EnglandTITLE: 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 EnglandTable 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 EnglandG.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 BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 Revision: 1 02-OCT-2012 Page 3 of 30 Printed in EnglandThis 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 4 of 30 Printed in England2.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 EnglandTerminals 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 EnglandC.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 EnglandD.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. INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 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. INSPECTION SERVICE BULLETIN 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 EnglandE.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. INSPECTION SERVICE BULLETIN 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. INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 Revision: 1 02-OCT-2012 Page 12 of 30 Printed in EnglandF.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 EnglandG.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 EnglandThere 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. INSPECTION SERVICE BULLETIN 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 EnglandH.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. INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 Revision: 1 02-OCT-2012 Page 16 of 30 Printed in England3.Material information None. INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

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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 ...................... INSPECTION SERVICE BULLETIN 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 EnglandAt 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). INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

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 BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 Revision: 1 02-OCT-2012 Page 21 of 30 Printed in EnglandAt 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 ...................... INSPECTION SERVICE BULLETIN BAe 146 SERIES/AVRO 146-RJ SERIES AIRCRAFT

Date: 26-SEP-2011 ISB. 24-143 Revision: 1 02-OCT-2012 Page 23 of 30 Printed in EnglandEngine 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

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### 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

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