DATE 

REV 

MODEL AFFECTED: 

SUBJECT: 

TECHNICAL BULLETIN 

Bell Helicopteri i ~:J i ,t•) ~I A Subsidiary of Textron Inc. 

230 

No. 

Date 

Page 

FUEL VALVE SWITCH, REWIRING OF 

HELICOPTERS AFFECTED: Model 230 helicopters serial number 23001 

through 23038 

230-03-35 

06-11-03 

1 of 8 

COMPLIANCE: Bell Helicopter recommends compliance with this 

bulletin. 

DESCRIPTION: 

We have received field reports of failure of the switches, P/N 1 0648BH1-1, that control 

the operation of the No.1 and No. 2 engine fuel valves. There is a possibility that the 

switch may fail in flight, due to vibration, causing the switch to open and then causing 

the fuel valve to revert to the closed condition and subsequent shut down of the 

associated engine. 

APPROVAL: 

The engineering design aspects of this bulletin are Transport Canada approved. 

MANPOWER: 

Approximately 4.0 man-hours are required to complete this bulletin. Man-hours are 

based on hands-on time, and may vary with personnel and facil ities available. 

MATERIALS: 

None 

AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT 

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER 
. 

TB 230-03-35 

Page 2 of 8 

SPECIAL TOOLS: 

M81969/14-11 Insertion/Extraction tool 

WEIGHT AND BALANCE: 

Not affected 

ELECTRICAL LOAD DATA: 

Not affected 

REFERENCES: 

BHT -230-MM-1 0 Maintenance Manual 

BHT -230-MM-12 Maintenance Manual 

PUBLICATIONS AFFECTED: 

BHT-230-MM-10 Maintenance Manual 

BHT -230-MM-12 Maintenance Manual 

ACCOMPLISHMENT INSTRUCTIONS: 

1. Prepare the helicopter for maintenance 

2. Ensure all electrical power is removed from the helicopter. 

3. Disconnect the aircraft battery. 

4. Carefully lower the overhead console. 

5. Locate the No.1 engine Fuel Valve Switch (1 S3). 

6. Using an extraction tool, P/N M81969/14-11 , remove the following wires from 

switch (1 S3): 

J5A22 from position 7, 

J6A22 from position 8, 

L 123A22 from position 10, 

L 122A22 from position 11. 

Q121A22 from position 13, 

Q227A22N from position 14, 

Q1 46A22 from position 16, 

Q144A22 from position 17. 

7. Using an insertion tool, P/N M81969/14-11 , insert the following wires into switch 

(1 S3): 
J5A22 into position 5, 

J6A22 into position 6, 

L 122A22 into position 10, 

L 123A22 into position 11 , 

0227 A22N into position 13, 

0121A22 into position 14, 

0144A22 into position 16, 

0 146A22 into position 17. 

8. Locate the No.2 engine Fuel Valve Switch (1 S8). 

TB 230-03-35 

Page 3 of 8 

9. Using an extraction tool, P/N M81969/14-11, remove the following wires from 

switch (1 S8): 

J1A22 from position 7, 

J2A22 from position 8, 

L 1 09A22 from position 10, 

L 1 08A22 from position 11 . 

0148822 from position 13, 

0228A22N from position 14, 

0141A22 from position 16, 

0 140A22 from position 17. 

10. Using an insertion tool, P/N M81969/14-11 , insert the following wires into switch 

(1 S8): 

J1A22 into position 5, 

J2A22 into position 6, 

L 1 08A22 into position 10, 

L 1 09A22 into position 11, 

0228A22N into position 13, 

0148822 into position 14, 

0140A22 into position 16, 

0141 A22 into position 17. 

11. Carefully raise the overhead control console and re-secure. 

12. Push the ENG 1 FUEL VALVE switch (1 S3) and the ENG 2 FUEL VALVE 

switch (1 S8) to the "in" position. 

13. Apply a 28 Vdc power source to the aircraft. (8HT-230-MM-1 0). 

14. Push the ENG 1 FUEL VALVE switch (1S3) to ON and observe the following: 

a. The green light of the switch comes on. 

b. The engine No.1 fuel valve opens. 

c. The ENG 1 FUEL VALVE caution panel segment will come on for as 

long as the fuel shut valve is operating .. 
TB 230-03-35 

Page 4 of 8 

15. Push the ENG 2 FUEL VALVE switch (1S3) to ON and observe the following: 

a. The green light of the switch comes on. 

b. The engine No.2 fuel valve opens. 

c. The ENG 2 FUEL VALVE caution panel segment will come on for as 

long as the fuel shut valve is operating . 

16. Open the engine No.1 and engine No.2 FIRE EXTG circuit breakers (24CB1 

and 24CB2). 

17. Push in the FIRE/ARM/ENG 1 switch (1DS1) to ARM and observe the following: 

a. The engine No.1 fuel valve closes. 

b. The ENG 1 FUEL VALVE caution panel segment will come on for as 

long as the fuel shut valve is operating. 

18. Push the FIRE/ARM/ENG 1 switch. 

19. Push in the FIRE/ARM/ENG 2 switch (1 DS2) to ARM and observe the following : 

a. The engine No.2 fuel valve closes . 

b. The ENG 2 FUEL VALVE caution panel segment will come on for as 

long as the fuel shut valve is operating. 

20. Push the FIRE/ARM/ENG 2 switch. 

21 . Close the engine No.1 and engine No.2 FIRE EXTG circuit breakers (24CB1 

and 24CB2). 

21 . Carry out an operational test of the ignitor system. (BHT-230-MM-1 0). 

22. Annotate the helicopter records to reflect compliance with this bulletin. 

23. Return the helicopter to flight status. 
WIRE NO. 

JIA22 

J2A22 

L108A22 

L109A22 

Q140A22 

Q141A22 

0148822 

Q228A22N 

J5A22 

J6A22 

L122A22 

L123A22 

Q121A22 

Q144A22 

Q146A22 

Q227A22N 

RE-TERMINATION WIRE CHART 

REF DES FROM PIN 

188 7 

188 8 

188 11 

188 10 

188 17 

188 16 

188 13 

188 14 

183 7 

183 8 

183 11 

183 10 

183 13 

183 17 

183 16 

183 14 

Figure 1 

Wire Termination Chart 

TO PIN 

5 

6 

10 

11 

16 

17 

14 

13 

5 

6 

10 

11 

14 

16 

17 

13 

TB 230-03-35 

Page 5 of 8 
TB 230-03-35 

Page 6 of 8 

TOP 

1 c 2 

Figure 2 

Switch Termination Schematic 
(~------r-------~---J6A22 

ENG 1 FUEL VALVE SWITCH 

I 1s3 I 

L48822-----( 

L42E22N -----2 

PRE MOD 

ENG 1 FUEL VALVE SWITCH 

I 1s3 I 

TB 230-03-35 

Page 7 of 8 

L48822 ---( l ON 

(~----~r------------- J6A22 

POST MOD 

03538001 

Figure 3 

No.1 Fuel Valve Switch Wiring Diagram 
TB 230-03-35 

Page 8 of 8 

~------~------4-----J2A22 

:r------rr------------- J2A22 

ENG 2 FUEL VALVE SWITCH 

I 1S8 I 

L47J22 -----( 

L40G22N ---r' 

PRE MOD 

ENG 2 FUEL VALVE SWITCH 

I 1S8 I 

L47J22 ---<' 1 ON 

L40G22N ---r' 

POST MOD 

Figure 4 

No.2 Fuel Valve Switch Wiring Diagram 

03538002