(j)
Defuel until measuring sticks show desired quantity of fuel remaining (applicable for No. 1 or 2 tank only) or until fuel truck flowmeter ceases to show fuel flow.
(k)
Stop fuel truck defueling pump.
(l)
Place defueling valve handle in CLOSED position and close defueling valve access door.
(m)
Close nozzle fuel flow shutoff handle. Disconnect defueling hose nozzle and disconnect nozzle bonding cable if connected.
(n)
Install fueling receptacle cap and close fueling station access door.
(o)
Close fuel crossfeed valve if opened.
(p)
Open fuel boost pump bypass valves if closed.
(q)
Install access panels removed (AMM 28-11-11/401).
(r)
If tanks are to be completely defueled, drain sump fuel from tanks per steps C.(21) thru C.(24).
5C1
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(3) On ALL EXCEPT airplanes with boost pump bypass valve with valve lock actuating arm:
(a)
Perform steps (2)(d) thru (i).
(b)
Defuel until tank No. 2 measuring sticks show desired quantity of fuel remaining in tank or until fuel truck ceases to show fuel flow.
(c)
Stop fuel truck defueling pump.
(d)
If defueling tank No. 1 or center tank, purge tank No. 2 (AMM 28-10-0/201).
(e)
Gain access to, and remove tank No. 2 boost pump bypass valve per 28-22-61 and install cap on bypass valve inlet fuel line.
(f)
If defueling center tank:
1) Close tank No. 2 fwd and aft boost pump removal valves.
2) Start fuel truck defueling valve.
3) Defuel until fuel truck flowmeter ceases to show fuel flow.
4) Stop fuel truck defueling pump.
(g)
If defueling tank No. 1: 1) Manually open crossfeed valve. 2) Gain access to center tank boost pumps and close both center tank boost pump
removal valves.
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3) Start fuel truck defueling pump. 4) Defuel until tank No. 1 measuring sticks show desired quantity of fuel remaining in tank or until fuel truck ceases to show fuel flow. 5) Stop fuel truck defueling pump.
(h)
Perform steps (2)(1) thru (n)
(i)
Remove cap from tank No. 2 boost pump bypass valve inlet fuel line, if previously installed, and install bypass valve (Ref 28-22-61).
(j)
Open any boost pump removal valves previously closed.
(k)
Perform steps (2)(q) thru (r).
F. Defuel Through Pressure Fueling Receptacle Using Auxiliary Defueling External Power Control Unit (PCU)
NOTE: This is a selective (single tank) method of defueling and is intended to be used mainly where it is not possible to power up the boost pumps through the airplane electrical wiring system. The PCU, combined with ground electrical power, provides cable connections, control switches and pressure indicating lights for direct connection to one or both boost pumps of any fuel tank.
(1)
Ground airplane and fuel truck (Ref 20-41-11 MP).
(2)
Check that all fuel system circuit breakers on P6 circuit breaker panel are open.
(3)
Open fueling station access door (Fig. 201) and remove fueling nozzle receptacle cap.
(4)
Connect defueling hose nozzle to fueling nozzle receptacle. Open nozzle fuel flow shutoff handle.
NOTE: Defueling nozzle should be equipped with a filter screen to protect collecting tank from any foreign matter from airplane fuel tank and fuel lines.
(5)
Open defueling valve access door (Fig. 202) and place manual actuation lever in OPEN position.
(6)
If defueling using fuel tank boost pumps located in left wing, open fuel crossfeed valve with manual override lever.
(7)
To gain access to engine fuel shutoff valves and tank No. 1 or 2 forward boost pumps, extend flaps and install leading edge flap locks (Ref 27-81-0 MP).
WARNING: REFER TO 27-81-0 MP FOR LOCK INSTALLATION. FLAPS ARE FAST ACTING AND CAN CAUSE SERIOUS INJURY TO PERSONNEL.
(8)
Open engine No. 2 engine fuel shutoff valve using manual override control lever.
(9)
Remove applicable boost pump access panel (dry bay) (Ref 28-22-41 R/I).
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(10)
Prepare the power control unit (PCU) (Fig. 204).
(a)
Remove cable assemblies from storage box and place PCU on top of storage box so that PCU control panel is a minimum of 30 inches above ground level. Locate box and PCU within convenient cable reach of desired airplane boost pumps.
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