DATE 

REV 

MODEL AFFECTED: 

SUBJECT: 

TECHNICAL BULLETIN 

Bell Helicopter i i }:j i ,t •) : I 

A Subsidiary of Textron Inc. 

222U 

No. 

Date 

Page 

FUEL VALVE SWITCH, REWIRING OF 

HELICOPTERS AFFECTED: Model 222U helicopters serial number 47501 

through 47574 

222U-03-96 

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 0648BH 1-1 , 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 facilities available. 

MATERIALS: 

None 

SPECIAL TOOLS: 

M81969/14-11 Insertion/Extraction tool 

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

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER 
TB 222U-03-96 

Page 2 of 8 

WEIGHT AND BALANCE: 

Not affected 

ELECTRICAL LOAD DATA: 

Not affected 

REFERENCES: 

BHT -222U-MM-1 0 Maintenance Manual 

BHT -222U-MM-12 Maintenance Manual 

PUBLICATIONS AFFECTED: 

BHT-222U-MM-10 Maintenance Manual 

BHT-222U-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): 

Q151A22 from position 5, 

Q121A22 from position 6, 

J5A22 from position 7, 

J6A22 from position 8, 

L 123A22 from position 10, 

L 122A22 from position 11 . 

Q227A22N from position 14, 

Q 146A22 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, 
0151A22 into position 7, 

0121A22 into position 8, 

L 122A22 into position 10, 

L 123A22 into position 11, 

0227 A22N into position 13, 

0144A22 into position 16, 

0146A22 into position 17. 

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

TB 222U-03-96 

Page 3 of 8 

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

switch ( 1 S8): 

0149A22 from position 5, 

0148822 from position 6, 

J1A22 from position 7, 

J2A22 from position 8, 

L 1 09A22 from position 10, 

L 1 08A22 from position 11 . 

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, 

0149A22 into position 7, 

0148822 into position 8, 

L 1 08A22 into position 10, 

L 1 09A22 into position 11 , 

0228A22N into position 13, 

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 (1S3) and the ENG 2 FUEL VALVE 

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

13. Apply a 28 Vdc power source to the aircraft. (8HT-222U-MM-10). 

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. 
TB 222U-03-96 

Page 4 of 8 

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

long as the fuel shut valve is operating .. 

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. Set the ENGINE 1 ARM fire extinguisher switch 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. Set the ENGINE 1 ARM fire extinguisher switch to NORM and the ENG 1 FUEL 

VALVE switch to OFF. 

19. Set the ENGINE 2 ARM fire extinguisher switch 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. Set the ENGINE 2 ARM fire extinguisher switch to NORM and the ENG 2 

FUEL VALVE switch to OFF. 

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-222U-MM-10). 

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

23. Return the helicopter to flight status. 
RE-TERMINATION WIRE CHART 

WIRE NO. REF DES FROM PIN 

J5A22 1S3 7 

J6A22 1S3 8 

L122A22 1S3 11 

L123A22 1S3 10 

Q121A22 1S3 6 

Q144A22 1S3 17 

Q146A22 1S3 16 

Q151A22 1S3 5 

Q227A22N 1S3 14 

JIA22 1S8 7 

J2A22 1S8 8 

L 108A22 1S8 11 

L 109A22 1S8 10 

Q140A22 1S8 17 

Q141A22 1S8 16 

0148822 1S8 6 

Q149A22 1S8 5 

Q228A22N 1S8 14 

Figure 1 

Wire Termination Chart 

TO PIN 

5 

6 

10 

11 

8 

16 

17 

7 

13 

5 

6 

10 

11 

16 

17 

8 

7 

13 

TB 222U-03-96 

Page 5 of 8 
TB 222U-03-96 

Page 6 of 8 

1 

TOP 

c 2 

Figure 2 

Switch Termination Schematic 
) 

) 

) 

\ 

ENG 1 FUEL VALVE SWITCH 

I 1S3 I 

L48C22 --2 

TB 222U-03-96 

Page 7 of 8 

- L122A22 

s--

J6A22 

L42C22N --2 

PRE MOD 

ENG 1 FUEL VALVE SWITCH 

I 1S3 I 

POST MOD 

Figure 3 

JSA22 -----------------r 

Q151A22 --------T' 

L42C22N--2 

Q155E22 ---,-> 

Q123A22 ---T' 

03536001 

No.1 Fuel Valve Switch Wiring Diagram 
TB 222U-03-96 

Page 8 of 8 

' 

) 

' 

l 

s---

J2A22 

ENG 2 FUEL VALVE SWITCH 

I 1s8 I 

L47K22 ------( 

L43C22N -----( 

PRE MOD 

ENG 2 FUEL VALVE SWITCH 

I 1s8 I 

J1A22 ---------.' 

Q149A22 ----------r' 

L42C22N -----( 

Q157E22 ------2 

Q122A22 ---r' 

POST MOD 

03536002 

Figure 4 

No.2 Fuel Valve Switch Wiring Diagram