D.  
Preconditions

 S 865-081
 (1)  
These conditions are necessary for this task:

 (a)  
Jettison Pump Systems serviceable.

 (b)  
A specfic quantity of fuel is not necessary for this task.

 (c)  
Electrical Power is On (AMM 24-22-00/201).

 (d)  
Integrated Display Unit System is Serviceable (AMM 31-61-00/501).

 (e)  
CMCS is serviceable (AMM 45-10-00/501).

 E.  
Prepare for the Test

 (1)  
Supply electrical power (AMM 24-22-00/201).

 S 865-053

 (2)  
Make sure the airplane is in a 0.5 degree (| 2°) nose down and 0.0 degree (| 2°) roll attitude.

 S 865-055
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 S 495-050
 (3)  Do a check of the fuel quantity in the center wing and inboard main tanks to find out if the fuel inlets are below the level of the fuel.
 NOTE: At different pitch and roll attitudes the fuel quantity
____ that is necessary to cover the pump fuel inlets will change. See the pump fuel inlet graphs in this procedure: Test of the Motor/Impeller Unit Installation (AMM 28-31-01/401).
 (a)  
If the center wing tank contains a minimum of 15,000 pounds (6800 kilograms) the fuel inlet is below the level of fuel. At different pitch and roll attitudes, this fuel quantity can be less.

 (b)  
If the No./2 and No./3 main tanks each contain a minimum of 12,500 pounds (5700 kilograms) the fuel inlets are below the level of the fuel. At different pitch and roll attitudes, this fuel quantity can be less.

 S 865-051
 (4)  
If the fuel inlets are above the level of the fuel, open these circuit breakers and attach DO-NOT-CLOSE tags:

 (a)  
On the left DC power distribution panel, P414: 1) 414D2, FUEL OVRD/JSTN PUMP CTR LEFT 2) 414C2, FUEL OVRD/JSTN PUMP FWD 2 3) 414C5, FUEL OVRD/JSTN PUMP FWD 3

 (b)  
On the right DC power distribution panel, P415: 1) 415M32, FUEL OVRD/JSTN PUMP CTR RIGHT 2) 415A38, FUEL OVRD/JSTN PUMP AFT 2 3) 415B38, FUEL OVRD/JSTN PUMP AFT 3

 S 865-057
 (5)  
Make sure all the switches for the boost pumps and the override/jettison pumps (installed on the P5 pilots' overhead panel) are in the OFF position.

 S 865-059

 (6)  
Make sure the FUEL CONTROL switches on the aisle stand are in the CUTOFF position.

 S 865-061

 (7)  
Make sure that all the fuel crossfeed valves are in the closed position.

 F.
Low Pressure Lights Test

 S 715-063
 (1)  
Do a test for the lamps in the pump control switches.

 (a)  
Hold the IND LTS switch on the pilots' overhead panel to the TEST position.

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747-400 MAINTENANCE MANUAL
 (b)  
Make sure all the low pressure lights on the fuel management control module come on.

 (c)  
Release the IND LTS switch.

 (d)  
Make sure the low pressure lights for the override/jettison pumps go off.

 G.
Low Pressure Indicating System Test

 S 715-031
 (1)  
Do a test on the fuel override/jettison low pressure indication system.

 (a)  
Push the left override/jettison pump switch for the center wing tank on the fuel management control module to start the pump.

 (b)  
If there is fuel in the center wing tank, make sure the low pressure light comes on momentarily then goes off.

 (c)  
If the circuit breakers for the override/jettison pumps are open, make sure the low pressure light comes on.

　
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