(22) Drain sump fuel from defueled tank.
NOTE: Optimum attitude for sump draining of fuel is one degree nose down pitch/zero degree roll.
(a)
Remove fuel sump drain valve for main tank (Fig. 202) (Ref\28-11-21 R/I).
(b)
Install sump fuel drain adapter (Fig. 203).
(c)
Electrically ground container or any associated equipment to basic airplane structure, but not in immediate vicinity of drainage (Ref Chapter 20).
(d)
Drain sump fuel from defueled tank through ump drain valve fitting, using sump fuel drain adapter.
WARNING: DRAIN SUMP FUEL IN PROPERLY MARKED AND APPROVED CONTAINERS.
(e)
Remove drain adapter and install drain valve.
(23)
Drain sump fuel from defueled center tank.
(a)
Adjust airplane attitude to 1/4-degree nose up and zero-degree roll for maximum sump drainage.
(b)
Open sump valve access door for center tank (Fig. 202).
(c)
Electrically ground metal container or any associated equipment to basic airplane structure, but not in immediate vicinity of drainage (Ref Chapter 20).
(d)
Open sump drain by turning clockwise and pushing up. Drain will have to be held in this position until all fuel flow has stopped. A tool may be fabricated locally to aid in draining fuel (Fig. 203).
WARNING: DRAIN SUMP FUEL IN A PROPERLY MARKED AND APPROVED CONTAINER.
(e)
Close sump drain by releasing and turning counterclockwise. Remove tool and close sump valve access door.
(24)
Open boost pump drain cocks, and drain fuel from pumps.
(25)
Close boost pump drain cocks.
(26)
If entry is to be made into defueled tank, tank must be purged (AMM 28-10-0/201).
Fuel Sump Draining Tools 5B8
28-23-0 Figure 203 Sep 20/82
Page 206
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
WARNING: ENSURE THAT SUMP DRAINAGE WAS COMPLETED WITH AIRPLANE ATTITUDE AS NOTED IN PAR. 2.C.(23)(a) BEFORE CENTER TANK ENTRY IS ATTEMPTED OR SPILLAGE OF TRAPPED FUEL WILL OCCUR WHEN ACCESS PANEL IS LOOSENED.
D. Defuel Through Pressure Fueling Receptacle Using Airplane Boost Pump Only
NOTE: Defueling nozzle should be equipped with a filter screen.
(1)
Ground airplane and fuel truck (AMM 20-41-11/201).
(2)
Perform steps 2.C.(2) thru (12), (14) thru (16), and (18) thru (26).
E. Defuel Through Pressure Fueling Receptacles Using Fuel Truck Defueling (Suction) Pump Only
NOTE: This method of defueling is extremely slow and should only be used when electrical power cannot be applied to airplane. Defueling nozzle should be equipped with a filter screen. On ALL EXCEPT airplanes with boost pump bypass valves with valve lock actuating arms, tank No. 2 must be defueled and purged if tank No. 1 or center tank are to be defueled.
(1)
Ground airplane and fuel truck (AMM 20-41-11/201).
(2)
On airplanes with boost pump bypass valve with valve lock actuating arm:
(a)
If defueling tank No 1, manually open crossfeed valve and close tank No. 2 boost pump bypass valve.
(b)
If defueling center tank, manually open crossfeed valve and close boost pump bypass valves in tanks No 1 and 2.
(c)
If defueling tank No. 2, check that crossfeed valve is closed and tank No. 2 boost pump bypass valve is open.
(d)
Open fueling station access door and remove fueling nozzle receptacle cap.
(e)
Connect defueling hose nozzle bonding cable to jack on wing.
NOTE: Bonding cable is not required if electrical continuity exists between nozzle and receptacle.
(f)
Connect defueling hose nozzle to fueling nozzle receptacle. Open nozzle fuel flow shutoff handle.
CAUTION: BEFORE DEFUEL OPERATIONS, MAKE SURE THE HOSE NOZZLE AND HOSE-END CONTROL VALVE (IF USED) ARE CONFIGURED PER THE SUPPLIER'S MAINTENANCE MANUAL. FAILURE TO DO SO COULD CAUSE DAMAGE TO THE AIRPLANE.
(g)
Check that fueling valve switches on P15 panel are in closed position.
(h)
Open defueling valve access door and place defueling valve handle in OPEN position.
(i)
Start fuel truck defueling pump.
NOTE: If it is difficult to get fuel to flow from airplane, use the fuel truck to pump the airplane lines full of fuel (pressure-prime) then start fueling truck defueling pump.
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