REFUEL/DEFUEL SYSTEM - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General
The Refuel/Defuel system controls the flow of fuel into or out of the aircraft. Refuel/defuel operations are controlled from a refuel/defuel control panel in the RH lower belly fairing. A refuel/defuel coupling (installed in the leading edge of the RH wing) is the interface between the fuel tanks and the external fuel source.

The refuel/defuel system controls the flow of fuel into or out of the aircraft. A refuel/defuel operation is controlled from the refuel/defuel control panel installed on right side of the lower belly-fairing. There is a refuel/defuel coupling (installed in the leading edge of each wing) which is the interface between the fuel tanks and the external fuel source.
The Refuel/Defuel system controls the flow of fuel into or out of the aircraft. A refuel/defuel operation is controlled from the refuel/defuel control panel in the RH wing leading edge. There is a refuel/defuel coupling (also in the leading edge of the RH wing) that is the interface between the fuel tanks and the external fuel source.

A. Refuel
There are two different procedures available to refuel the aircraft, these are:

a pressure refuel (automatic or manual)
a gravity overwing refuel.

NOTE: It is recommended that you keep to one type of fuel. Although approved types can be mixed if necessary to continue operation. Refer to Section 2 of your Flight Manual (Ref. FM Section 2) for a complete list of approved fuels. Refer to Airbus Cold Weather Operations Information and Operations Policy Fueling Procedures for safety precautions with mixed fuel.

Pressure refuel (automatic or manual) is the only procedure available to refuel the aircraft.

To fill the fuel tanks to their maximum capacity, the aircraft must be level at zero degrees. It is possible to refuel an aircraft that is not more than two degrees from level, but it is possible that the tanks will not completely fill.

NOTE: For the New Engine Option (NEO) aircraft that has an Additional Center Tank (ACT) installed in the forward cargo compartment, the term ACT FWD can also be written as ACT 4.1.

During the automatic refueling, refueling of the wing tanks, the center tank and the installed ACT(s) occur at the same time. If the related ACTs are installed, they are refueled in the sequence ACT AFT1, ACT AFT2 and ACT FWD. The inlet valve(s) stop(s) the refueling of the related tank(s) when:

The tanks are filled to the preselected fuel quantity
The related tank(s) is (are) full of fuel.

During the automatic refueling, refueling of the wing tanks, center tank and Additional Center Tanks (ACTs) occurs at the same time. If the related ACTs are installed, they are refueled in order that follow ACT AFT1 and ACT AFT2. The inlet valve(s) stop(s) refueling of the related tank(s) when:

The tanks are filled to preselected fuel quantity
The related tank(s) is (are) full of fuel.

During manual refueling, only selected tanks are filled.

B. Defuel
The main fuel pumps (Ref. AMM D/O 28-21-00-00) remove the fuel from the fuel tanks and supply it to the refuel/defuel coupling where it can be removed from the aircraft. The defuel/transfer valve, when open, connects the main fuel pump system (Ref. AMM D/O 28-21-00-00) to the refuel/defuel system.
The main fuel pumps (Ref. AMM D/O 28-21-00-00) remove the fuel from the wing fuel tanks and supply it to the refuel/defuel coupling where it can be removed from the aircraft. The defuel/transfer valve, when open, connects the main fuel pump system (Ref. AMM D/O 28-21-00-00) to the refuel/defuel system. The main transfer system (Ref. AMM D/O 28-26-00-00) transfers fuel from the center tank to the wing tanks.
Fuel is removed from the aircraft by the operation of the main fuel pump system (Ref. AMM D/O 28-21-00-00). The pumps remove the fuel from the related wing tank and supply it to the crossfeed system (Ref. AMM D/O 28-23-00-00). This system connects, through the defuel/transfer valve, to the refuel/defuel system.

The refuel/defuel system returns fuel to the refuel/defuel coupling where it is removed from the aircraft. Before you supply fuel to the refuel/defuel coupling make sure that the defuel/transfer valve and the crossfeed valve (Ref. AMM D/O 28-23-00-00) is open.

Fuel in the center (transfer) tank is moved to the wing tanks by the operation of control valves in the main transfer system (Ref. AMM D/O 28-26-00-00). Fuel in the ACT(s) (when installed) must be moved to the center tank. In the ACT transfer system, fuel is moved by the operation of ACT transfer pump (Ref. AMM D/O 28-28-00-00).
Defuel
Fuel is removed from the aircraft by operation of the main fuel pump system (Ref. AMM D/O 28-21-00-00). The pumps remove fuel from the related wing tank and supply the crossfeed system (Ref. AMM D/O 28-23-00-00). This system connects, through the defuel/transfer valve, to the refuel/defuel system.

The refuel/defuel system returns fuel to the refuel/defuel coupling where it is removed from the aircraft. The defuel/transfer valve and the crossfeed valve (Ref. AMM D/O 28-23-00-00) must be open before fuel can be supplied to the refuel/defuel coupling.

Fuel in the center (transfer) tank is moved to the wing tanks by operation of control valves in the main transfer system (Ref. AMM D/O 28-26-00-00). Fuel in the ACT/s (when installed) must be moved to the center tank. The fuel is moved by operation of the transfer pump in the ACT transfer system (Ref. AMM D/O 28-28-00-00).

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2. Component Location

Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel 800VU - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel 800VU and 801VU - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Coupling - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Forward ACT Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Aft ACT(s) Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel (800VU and 801VU) - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Coupling - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Aft ACT(s) Refuel/Defuel System - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel (800VU and 801VU) - Component Location ** ON A/C NOT FOR ALL

Refuel/Defuel Coupling - Component Location ** ON A/C NOT FOR ALL

FIN	FUNCTIONAL DESIGNATION	PANEL	ZONE	ATA REF
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11QM	VALVE-DEFUEL/TRANSFER	148AZ	148	28-25-43
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11QM	VALVE-DEFUEL/TRANSFER		148	28-25-43
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19QM	CANISTER-REFUEL VALVE, L WING TK	540JB	540	28-25-52
20QM	CANISTER-REFUEL VALVE, R WING TK	640JB	640	28-25-52
31QM	VALVE-FUEL DRAIN, L WING TK	540AB	540	28-25-44
32QM	VALVE-FUEL DRAIN, R WING TK	640AB	640	28-25-44
40QM	CPLG-REFUEL/DEFUEL, R	621AZ	620	28-25-41
41QM	CAP-REFUEL/DEFUEL COUPLING, R	621AZ	620	28-25-41
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42QM	ADAPTER-OVERWING REFUEL, L	540AT	540	28-11-43
43QM	ADAPTER-OVERWING REFUEL, R	640AT	640	28-11-43
44QM	CAP-OVERWING REFUEL, L	540AT	540	28-11-43
45QM	CAP-OVERWING REFUEL, R	640AT	640	28-11-43
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54QM	CHECK VALVE-SPILL PIPE, L WING TK	540KB	540	28-25-47
55QM	CHECK VALVE-SPILL PIPE, R WING TK	640KB	640	28-25-47
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82QM	V BAND CLAMP-DEFUEL XFR VALVE ACTR		148	28-10-00
88QM	CANISTER-REFUEL VALVE, CTR TK	148AZ	142	28-25-52
97QM	VALVE-PRESSURE RELIEF, CTR TK	148AZ	142	28-25-45
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100QM	COUPLING-REFUEL/DEFUEL, L	521AZ	520	28-25-41
101QM	CAP-REFUEL/DEFUEL COUPLING, L		520	28-25-41
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116QM	SHROUD-REFUEL/DEFUEL CPLG, R	621BZ	620	28-25-49
117QM	PLATE-SHRD BACKING, R REFUEL/DEFUEL CPLG	621BZ	620	28-25-49
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118QM	SHROUD-REFUEL/DEFUEL CPLG, L	521BZ	520	28-25-49
119QM	PLATE-SHRD BACKING, L REFUEL/DEFUEL CPLG	521BZ	520	28-25-49
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161QM	VALVE-AIR INLET		540	28-25-57
162QM	VALVE-AIR INLET		640	28-25-57
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164QM	CANISTER-REFUEL VALVE, ACT		152	28-25-52
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7QU	VALVE-REFUEL, L WING TK	522JB	520	28-25-51
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7QU	VALVE-REFUEL, L WING TK		520	28-25-51
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8QU	VALVE-REFUEL, R WING TK	622JB	620	28-25-51
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8QU	VALVE-REFUEL, R WING TK		620	28-25-51
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10QU	VALVE-REFUEL, CTR TK	148AZ	148	28-25-51
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10QU	VALVE-REFUEL, CTR TK		148	28-25-51
** ON A/C ALL
11QU	ACTUATOR-DEFUEL/TRANSFER VALVE	148AZ	148	28-25-53
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41QU	VALVE-REFUEL, ACT		152	28-25-51
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41QU	VALVE-REFUEL, ACT		147	28-25-51

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3. System Description
The refuel/defuel system has these components:

Refuel/defuel control panel 800VU

The wing and the center tanks refuel/defuel system has these components:

Refuel/defuel control panel 800VU

a refuel/defuel coupling with a refuel/defuel coupling cap

two refuel/defuel couplings with their refuel/defuel coupling caps

three refuel valves
three refuel diffusers
a defuel/transfer valve
a refuel/defuel gallery
two overwing refuel adapters with their overwing refuel caps
two fuel drain valves
two air inlet valves.

three refuel valves
five refuel diffusers
a defuel/transfer valve
a refuel/defuel gallery
two refuel spill pipes
two refuel spill pipe check valves
two overwing refuel adapters with their overwing refuel caps
two fuel drain valves
two air inlet valves.

The ACT refuel/defuel system is an extension of the wing and the center tanks refuel/defuel system and includes these components:

Refuel/defuel control panel 801VU
Refuel valve 41QU
Forward ACT isolation valve 236QM
Transfer valve 165QM.

When the ACT(s) is(are) installed, each ACT includes:

Inlet valve 228QM*
Restrictor valve 230QM*
Twin motor actuator 94QH*.

The ACT refuel/defuel system is an extension of the wing and the center tanks refuel/defuel system and includes the components that follow:

Refuel/defuel control-panel 801VU
Refuel valve 41QU
Transfer valve 165QM.

When the ACT(s) is (are) installed, each ACT includes:

Inlet valve 228QM*
Restrictor valve 230QM*
Twin motor actuator 94QH*.

four refuel valves
three refuel diffusers
a defuel/transfer valve
a refuel/defuel gallery
two overwing refuel adapters with their overwing refuel caps
two fuel drain valves
two air inlet valves
an ACT fuel pump (Ref. AMM D/O 28-28-00-00)
an ACT fuel transfer valve (Ref. AMM D/O 28-28-00-00).

When the ACT/s is/are installed these components are also included:

a fuel inlet valve in each installed ACT (Ref. AMM D/O 28-28-00-00)
a refuel restrictor valve in each installed ACT (Ref. AMM D/O 28-28-00-00).

The refuel/defuel control panel is installed in the RH side of the belly fairing aft of FR36.
The refuel/defuel control panel has:

Control panel 800VU
Fuel quantity indicator 6QT
Fuel quantity preselector 5QT.

Access to the refuel/defuel control panel is through a quick-release door 192MB. This panel controls the operation of:

An automatic or manual pressure refuel
A pressure defuel (together with the main pumps (Ref. AMM D/O 28-21-00-00)).

The refuel/defuel control panel is installed in the RH side of the belly fairing aft of FR36.
The refuel/defuel control panel has:

a control panel 800VU
a control panel 801VU
a fuel quantity indicator 6QT
a fuel quantity preselector 5QT.

The refuel/defuel control panel controls the operation of:

an automatic or manual pressure refuel
a pressure defuel (together with the main pumps (Ref. AMM D/O 28-21-00-00), the main transfer system (Ref. AMM D/O 28-26-00-00) and the ACT transfer system (Ref. AMM D/O 28-28-00-00)).

Access to the refuel/defuel control panel is through a quick-release door 192MB.

The refuel/defuel control panel is in the leading edge of the RH wing, adjacent to the refuel/defuel coupling 40QM.
The refuel/defuel control panel has:

a control panel 800VU
a fuel quantity indicator 6QT
a fuel quantity preselector 5QT.

Access to the refuel/defuel control panel is through a quick-release door 622KB. This panel controls the operation of:

an automatic or manual pressure refuel
a pressure defuel (together with the main pumps (Ref. AMM D/O 28-21-00-00)).

The refuel/defuel control panel is installed in the RH side of the belly fairing aft of FR36.
The refuel/defuel control panel has:

a control panel 800VU
a fuel quantity indicator 6QT
a fuel quantity preselector 5QT.

Access to the refuel/defuel control panel is through a quick-release door 192MB. This panel controls the operation of:

an automatic or manual pressure refuel
a pressure defuel (together with the main pumps (Ref. AMM D/O 28-21-00-00) and the main transfer system (Ref. AMM D/O 28-26-00-00)).

Refuel/Defuel Control Panel (800VU and 801VU) - Component Location ** ON A/C NOT FOR ALL

The refuel/defuel control panel is installed in the right side of the belly fairing aft of FR36. Quick-release door 192MB gives access to the refuel/defuel control panel.
The refuel/defuel control panel has:

Two control panels 800VU and 801VU
Fuel quantity indicator 6QT
Fuel quantity preselector 5QT.

Control panel 800VU (which includes indicators and selector switches), together with the fuel quantity indicator and fuel quantity preselector, gives control of:

An automatic or manual pressure refueling
A manual (pressure) defueling of the wing and center tanks (uses the main pumps (Ref. AMM D/O 28-21-00-00)).

Control panel 801VU (which includes indicator(s) and selector(s) switch(es)) together with fuel quantity indicator 6QT and fuel quantity preselector 5QT gives control of the installed ACT(s) during:

An automatic or manual pressure refueling of the ACT(s)
A manual (pressure) defueling of the ACT(s) (uses the ACT transfer pump (Ref. AMM D/O 28-28-00-00)).

NOTE: The indicator(s) and the selector(s) switch(es) on control panel 801VU does(do) not operate if the related ACT(s) is(are) not installed.

The refuel/defuel coupling 40QM is the interface between the aircraft fuel tanks and the external fuel supply. It is attached to the forward face of the RH wing front spar, between RIB14 and RIB15. The refuel/defuel coupling cap 41QM is installed on the refuel/defuel coupling.

The refuel/defuel couplings 100QM(40QM) are the interfaces between the aircraft fuel tanks and the external fuel supply. A single coupling is attached to the forward face of each wing front spar, between RIB14 and RIB15. The refuel/defuel coupling caps 101QM(41QM) are installed on the refuel/defuel couplings.

The backing plate 117QM attaches the refuel/defuel coupling shroud 116QM to the refuel/defuel coupling. The shroud is also attached to the inside face of the wing skin. The shroud makes sure that fuel does not go into the leading edge of the wing.
The backing plate 119QM(117QM) attaches the refuel/defuel coupling shroud 118QM(116QM) to the refuel/defuel coupling by the backing plate 119QM(117QM). The shroud is also attached to the inside face of the wing skin. The shroud makes sure that fuel does not go into the leading edge of the wing.
The refuel valves 7QU(8QU) and 10QU are the interfaces between the refuel gallery and the related fuel tank. Each valve is solenoid controlled, but pressure operated. Thus when the solenoid is energized, and a refuel pressure is supplied, the valve opens. The refuel valve has a manual override-button. If the solenoid does not operate correctly, the manual override-button can be used to open the valve. The valve 7QU(8QU) is on the leading edge of the wing in the refuel valve canister 19QM(20QM). The valve is behind the access panel 522JB(622JB). The valve 10QU is installed on the rear spar (FR42) of the center tank in the refuel valve canister (88QM).

Refuel Valve - Schematic ** ON A/C NOT FOR ALL

Refuel valve 7QU (8QU) is installed on the leading edge of the left(right) wing (in refuel valve canister 19QM (20QM)) behind access panel 522JB (622JB). Refuel valves 10QU and 41QU are installed on the rear spar (FR42) of the center tank in their related refuel valve canisters 88QM and 164QM. The function and operation of refuel valves 7QU, 8QU, 10QU and 41QU are similar. They are the interface between the refueling gallery and their related fuel tank(s).

Each valve is solenoid controlled, but pressure operated. Thus, when the solenoid is energized and a fuel pressure is supplied, the valve opens. The refuel valve has a manual override-button. If the solenoid does not operate correctly, the manual override-button can be pushed in to let the valve open (when pressure is available).

Refuel valve 41QU is installed as part of the ACT provisions. If the ACT(s) is(are) not installed the valve stays closed and does not get a power supply from its C/B 43QU.

A. ACT Refuel Valve (41QU) and Canister (164QM)

Refuel Valve - Schematic ** ON A/C NOT FOR ALL

The refuel valve 41QU is the interface between the refuel gallery and the related fuel tank. The valve is solenoid controlled, but pressure operated. Thus when the solenoid is energized, and a refuel pressure is supplied, the valve opens. The refuel valve has a manual override-button. If the solenoid does not operate correctly, the manual override-button can be used to open the valve.

The ACT refuel valve 41QU is installed in the canister 164QM, at the rear spar FR42. The ACT refuel valve and canister are installed as part of the ACT system provision. They do not operate when the ACT/s is/are not installed.

Defuel/Transfer Valve and Actuator

Defuel/transfer valve (11QM) is in the center tank, on the rear spar. The defuel/transfer valve connects the main fuel pump system (Ref. AMM D/O 28-21-00-00) to the refuel gallery. When open, the valve lets the fuel in the main fuel pump system be moved into the refuel gallery. This lets the fuel be:

Moved from one tank to another
Delivered to the refuel/defuel coupling for removal from the aircraft.

The ACT fuel inlet valves, and their related actuators, are in the ACT/s (when installed) as follows:

inlet valve 166QM1 and actuator 5QH1 in ACT1
inlet valve 166QM2 and actuator 5QH2 in ACT2.

The actuators, 5QH1 and 5QH2, open their respective inlet valves when an automatic or manual fuel forward transfer or refuel is selected (Ref. AMM D/O 28-28-00-00).
A single motor actuator (11QU) operates the defuel/transfer valve. A V-band clamp (82QM) attaches the actuator to the defuel/transfer valve.
A MODE SELECT switch (3QU), on the refuel/defuel control panel (800VU), controls the operation of the defuel/transfer valve (11QM). The actuator (11QU) will open the defuel/transfer valve (11QM) when the switch (3QU) is moved to the DEFUEL XFR position. When the defuel/transfer valve is open, an OPEN light (21QU), adjacent to the switch (3QU) will come on. The actuator will close the defuel/transfer valve when the switch (3QU) is in the OFF or the REFUEL positions.
An air inlet valve is in the refuel gallery, adjacent to the rear face of the front spar. The air inlet valve lets air into the refuel gallery after the refuel procedure. Thus fuel can drain from the refuel gallery through the fuel drain valve 31QM(32QM). A pipe extends from the air inlet valve to the outboard side of RIB21. This pipe makes sure that the air inlet remains above the fuel level at all times. This stops the gravity movement of fuel from one wing tank to the other.
The air inlet valve 161QM(162QM) is on the inboard face of RIB16. A pipe connects the air inlet valve to the refuel gallery. The air inlet valve lets air into the refuel gallery after a refuel procedure. Thus fuel can drain from the refuel gallery through the fuel drain valve 31QM(32QM).
A fuel drain valve 31QM(32QM) is installed at the lowest point of the refuel gallery in each wing (the outboard face of RIB1). Fuel pressure in the refuel gallery closes the fuel drain valves. When the pressure source is removed the valve opens to allow fuel to drain into the wing tank from the refuel gallery.

The refuel gallery is a fuel pipe that connects from the LH wing tank refuel valve through to the RH wing tank refuel valve. From this pipe, other branch pipes supply fuel, through diffusers, to the fuel tanks.

The sealed RIB15 (Ref. AMM D/O 28-11-00-00) divides the wing tank into an inner and an outer cell. During a refuel operation the outer cell is filled first. The refuel spill pipe connects the wing tank outer cell to the wing tank inner cell. Thus, when the wing tank outer cell is full the spill pipe lets the fuel move into the wing tank inner cell. A diffuser, on the spill pipe, makes sure that the fuel goes into the inner cell smoothly. The spill pipe has a check valve 54QM(55QM). During flight the check valve makes sure that fuel that goes into the spill pipe goes back to the outer cell.
Each wing tank has an overwing refuel adapter 42QM(43QM). This can be used to refuel the aircraft when a pressure refuel source is not available. During an overwing refuel, the fuel only goes into the wing tank. It is then necessary to do a ground fuel transfer to get the fuel into the correct fuel-load configuration. The adaptor has an overwing refuel cap 44QM(45QM) which gives access to and seals the adaptor. The refuel adaptor and cap are installed in the upper wing surface (between RIB19 and RIB20) and has an electrical ground point adjacent to it.
The pressure relief valve 97QM is installed in the RH RIB1. If a center tank overflow occurs the pressure relief valve releases the fuel into the RH wing tank.
Forward ACT isolation valve 236QM is installed on the rear spar (FR42) of the center tank. It is installed in the refuel gallery that goes forward from ACT refuel valve 41QU. When the valve is close the ACT FWD (if installed) is isolated from the refuel/defuel system and from the ACT transfer system (Ref. AMM D/O 28-28-00-00)).
V-band clamp 249QM attaches actuator 92QH to the valve. The actuator has two motors. If the ACT FWD is not installed the valve stays close and power does not go to actuator 92QH.
An inlet valve is installed in the top face of each ACT. The valve controls the flow of fuel in or out of its related ACT. An actuator with two motors turns the valve through the open or shut position. One motor operates during auto control, the two motors operate during manual control.

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4. Power Supply
On the electrical schemes that follow:

ACT1 is related to ACT AFT1
ACT2 is related to ACT AFT2
ACT4 or ACT4.1 are related to ACT FWD.

On the electrical schemes that follow:

ACT1 is related to ACT AFT1
ACT2 is related to ACT AFT2

Refuel/Defuel System - Circuit Diagram ** ON A/C NOT FOR ALL

Refuel Defuel System - Circuit Diagram ** ON A/C NOT FOR ALL

Refuel/Defuel System - Circuit Diagram ** ON A/C NOT FOR ALL

Refuel/Defuel System - Circuit Diagram (with Provision for ACT) ** ON A/C NOT FOR ALL

Refuel/Defuel System - ACT Circuit Diagram (Provisioned for 2 ACT) ** ON A/C NOT FOR ALL

Refuel/Defuel System (Wing and Center Tank) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System (ACT Refuel Valve) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System (ACT AFT1 and ACT AFT2) - Power Supplies ** ON A/C NOT FOR ALL

Refue/Defuel System (ACT FWD) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System - Circuit Diagram ** ON A/C NOT FOR ALL

Refuel/Defuel System (Wing and Center Tank) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System (ACT Refuel Valve) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System (ACT AFT1 and ACT AFT2) - Power Supplies ** ON A/C NOT FOR ALL

Refuel/Defuel System - Circuit Diagram ** ON A/C NOT FOR ALL

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5. Interface

Refuel/Defuel System - Interfaces ** ON A/C NOT FOR ALL

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6. Component Description

A. Refuel/Defuel Control Panel FIN: 800-VU

The primary components on the refuel/defuel control panel are:

the control panel 800VU
the fuel quantity preselector 5QT (Ref. AMM D/O 28-42-00-00)
the fuel quantity indicator 6QT (Ref. AMM D/O 28-42-00-00).

The control panel 800VU has:

a BATT POWER (refuel-on-battery) switch 10PR (Ref. AMM D/O 24-67-00-00)
a MODE SELECT switch 3QU
a MODE SELECT OPEN light 21QU
a TEST P/BSW 2QJ (Ref. AMM D/O 28-46-00-00)
three fuel tank hi-level indicator-lights 3QJ, 4QJ, 5QJ (Ref. AMM D/O 28-46-00-00)
three REFUEL VALVES switches 4QU, 5QU, 6QU.

B. Refuel/Defuel Control Panel

Refuel/Defuel Control Panel (800VU and 801VU) - Component Location ** ON A/C NOT FOR ALL

The primary components on the refuel/defuel control panel are:

Control panel 800VU
Control panel 801VU
Fuel quantity preselector 5QT (Ref. AMM D/O 28-42-00-00)
Fuel quantity indicator 6QT (Ref. AMM D/O 28-42-00-00).

Control panel 800VU has:

BATT POWER (refuel-on-battery) toggle switch 10PR (Ref. AMM D/O 24-67-00-00)
MODE SELECT toggle switch (with guard) 3QU
MODE SELECT OPEN indicator light 21QU
TEST toggle switch 2QJ
HI LVL LEFT (3QJ), HI LVL RIGHT (4QJ) and HI LVL CTR (5QJ) indicator lights for each wing and center tanks
REFUEL VALVES toggle switches (with a guard) 4QU, 5QU and 6QU related to center tank, left wing tank and right wing tank.

Control panel 801VU has these controls for the ACTs:

Rotary selector switch 68QT
HI LVL indicator light 49QJ (for ACT AFT1) and 58QJ (for ACT AFT2)
AFT1 REFUEL VALVE toggle switch 40QU (for ACT AFT1) and AFT2 REFUEL VALVE toggle switch 42QU (for ACT AFT2). Both switches have a guard.

C. Refuel/Defuel Control Panel

The primary components on the refuel/defuel control panel are:

the control panel 800VU
the control panel 801VU
the fuel quantity preselector 5QT (Ref. AMM D/O 28-42-00-00)
the multi-tank indicator 6QT (Ref. AMM D/O 28-42-00-00).

The control panel 800VU has:

a BATT POWER (refuel-on-battery) toggle switch 10PR (Ref. AMM D/O 24-67-00-00)
a MODE SELECT toggle switch (with guard) 3QU
a MODE SELECT OPEN indicator light 21QU
a TEST toggle switch 2QJ (Ref. AMM D/O 28-46-00-00)
a HI LVL indicator light for each wing tank and the center tank 3QJ, 4QJ and 5QJ (Ref. AMM D/O 28-46-00-00)
a REFUEL VALVE toggle switch (with guard) for each wing tank and the center tank 4QU, 5QU and 6QU.

The control panel 801VU has these controls for the ACT/s:

two HI LVL indicator lights 49QJ and 58QJ (Ref. AMM D/O 28-46-00-00)
two REFUEL VALVE toggle switches (each with a guard) 40QU and 42QU
a FQI SELECT CTR/ACT rotary selector switch 67QT (Ref. AMM D/O 28-42-00-00).

The primary components on the refuel/defuel control panel are:

The control panel 800VU
The control panel 801VU
The fuel quantity preselector 5QT (Ref. AMM D/O 28-42-00-00)
The multi-tank indicator 6QT (Ref. AMM D/O 28-42-00-00).

The control panel 800VU has:

A BATT POWER (refuel-on-battery) toggle switch 10PR (Ref. AMM D/O 24-67-00-00)
A MODE SELECT toggle switch (with guard) 3QU
A MODE SELECT OPEN indicator light 21QU
A TEST toggle switch 2QJ (Ref. AMM D/O 28-46-00-00)
A HI LVL indicator light for each wing tank and the center tank 3QJ, 4QJ and 5QJ (Ref. AMM D/O 28-46-00-00)
A REFUEL VALVE toggle switch (with guard) for each wing tank and the center tank 4QU, 5QU and 6QU.

The control panel 801VU has these controls for the ACT/s:

Two HI LVL indicator lights 49QJ and 58QJ (Ref. AMM D/O 28-46-00-00)
Two REFUEL VALVE toggle switches (each with a guard) 40QU and 42QU.

D. Refuel/Defuel Coupling
40QM

Refuel Coupling and Cap ** ON A/C NOT FOR ALL

The refuel coupling has an L-shaped hollow body. At one end of the coupling is a mounting flange for attachment to the aircraft. At the other end a refuel adaptor is installed. The refuel adaptor contains:

an inner and outer compression spring
a valve
a valve seal
a coupling ring.

100QM(40QM)

Refuel Coupling and Cap ** ON A/C NOT FOR ALL

an inner and outer compression spring
a valve
a valve seal
a coupling ring.

An O-ring seal, between the refuel coupling body and the adaptor, prevents fuel leaks. When the refuel coupling is not in use, spring pressure holds the valve against the seal. This prevents a leakage of fuel from the coupling. The refuel coupling cap 41QM attaches to the coupling ring, and gives a secondary seal to the refuel/defuel coupling.
The coupling ring has a groove around its circumference. The groove lets the coupling ring break away from the refuel/defuel coupling if a specified force is applied to it. This prevents damage to the aircraft structure.

When the refuel hose engages the coupling ring, the valve moves off the seal. This opens the fuel system to the external fuel supply and seals the refuel hose to the coupling.
An O-ring seal, between the refuel coupling body and the adaptor, prevents fuel leaks. When the refuel coupling is not in use, spring pressure holds the valve against the seal. This prevents a leakage of fuel from the coupling. The refuel coupling cap 101QM(41QM) attaches to the coupling ring, and gives a secondary seal to the refuel/defuel coupling.
The coupling ring has a groove around its circumference. The groove lets the coupling ring break away from the refuel/defuel coupling if a specified force is applied to it. This prevents damage to the aircraft structure.

When the refuel hose engages the coupling ring, the valve moves off the seal. This opens the fuel system to the external fuel supply and seals the refuel hose to the coupling.

E. Refuel Coupling Cap
41QM

Refuel Coupling and Cap ** ON A/C NOT FOR ALL

The refuel coupling cap has:

A cover plate
A handle assembly
A guide ring assembly
Three rollers
A chain assembly.

Two screws attach the handle assembly to the cover assembly. When the trigger is pushed a torsion spring lifts the handle assembly.
The guide ring assembly and the rollers are in the cover body. The guide ring assembly is spring-loaded and has an O-ring. When the cap is installed the O-ring seals the cap to the refuel/defuel coupling and the rollers engage three bayonet lugs on the coupling. The cap is attached to the refuel/defuel coupling with the chain assembly. The chain assembly is spring-loaded inside a tube, this makes sure the chain goes safely into storage when the cap is installed.
101QM(41QM)

Refuel Coupling and Cap ** ON A/C NOT FOR ALL

The refuel coupling cap has:

A cover assembly
A handle assembly
A guide ring assembly
Three rollers
A chain assembly.

Two screws attach the handle assembly to the cover assembly. When the trigger is pushed a torsion spring lifts the handle assembly.
The guide ring assembly and the rollers are in the cover body. The guide ring assembly is spring-loaded and has an O-ring. When the cap is installed, the O-ring seals the cap to the refuel/defuel coupling and the rollers engage three bayonet lugs on the coupling. The cap is attached to the refuel/defuel coupling with the chain assembly. The chain assembly is spring-loaded into a protective cover for correct storage during installation of the cap.

F. Refuel Valve
7QU(8QU), 10QU

Refuel Valve - Schematic ** ON A/C NOT FOR ALL

The primary components of the refuel valve are:

the body
the piston and compression springs
the electro-magnetic valve (solenoid valve)
the manual command button and valve
the flap valves.

7QU(8QU), 10QU and 41QU

Refuel Valve - Schematic ** ON A/C NOT FOR ALL

Primary components of the refuel valve are:

The body
The piston and compression springs
The electro-magnetic valve (solenoid valve)
The manual command button and valve.

G. Refuel Valve 7QU(8QU), 10QU and 41QU
The piston and the body make an internal (piston) chamber. The solenoid valve controls the flow of fuel from the piston chamber to the refuel gallery. The manual command valve can also control the flow of fuel from the piston chamber to the refuel gallery. The flap valves stop fuel returning from the refuel gallery into the refuel valve. The refuel valves are installed in canisters:

the refuel valve 7QU in the refuel valve canister 19QM
the refuel valve 8QU in the refuel valve canister 20QM
the refuel valve 10QU in the refuel valve canister 88QM.

Refuel Valve - Schematic ** ON A/C NOT FOR ALL

The piston and the body make an internal (piston) chamber. The solenoid valve controls the flow of fuel from the piston chamber to the refuel gallery. The manual command valve can also control the flow of fuel from the piston chamber to the refuel gallery. The check valve stops fuel moving from the refuel gallery into the refuel valve. The refuel valves are installed in canisters:

Refuel valve 7QU in refuel valve canister 19QM
Refuel valve 8QU in refuel valve canister 20QM
Refuel valve 10QU in refuel valve canister 88QM
Refuel valve 41QU in refuel valve canister 164QM.

Operation

When the solenoid valve is de-energized a hydraulic-lock (fuel) is made behind the refuel valve piston. This hydraulic-lock and the compression springs hold the piston in the closed position.

When the solenoid valve is energized, the hydraulic-lock is released. The fuel pressure then pushes the piston (against the spring pressure) to the open position. The fuel that made the hydraulic-lock is pushed through the solenoid valve and into the refuel gallery. When the solenoid is de-energized, the hydraulic-lock is made again. Fuel pressure behind the piston increases and (together with the spring pressure) moves the piston to the closed position.

The manual command button (on the front of the valve body) connects directly to the manual command valve. If the solenoid valve does not operate, the manual command button can be pushed in (and held) to release the hydraulic-lock. The refuel valve then operates as usual.

H. Refuel Valve Canister
19QM(20QM), 88QM

Refuel Valve Canister ** ON A/C NOT FOR ALL

19QM(20QM), 88QM and 164QM

Refuel Valve Canister ** ON A/C NOT FOR ALL

I. Refuel Valve Canister 19QM(20QM), 88QM and 164QM
The primary components of the refuel valve canister are:

the canister body assembly
the check valve housing assembly
the sleeve
the spring
the check valve assembly.

Four screws and four nuts join the canister body assembly to the check valve housing assembly to make the refuel valve canister.
The refuel valve canister has an inlet port, an outlet port and a mounting flange for installation to the aircraft fuel tank.

The inlet and outlet ports have square mounting flanges, with four holes, for installation to the applicable aircraft system fuel-pipes. The mounting flange has four holes for installation to the aircraft and four threaded studs for installation of the refuel valve.

PTFE sealing rings prevent fuel leaks between the refuel valve, the sleeve, and the canister body.

When the refuel valve is removed the spring moves the sleeve over the inlet port to stop fuel flow into the canister. When the refuel valve is installed it pushes the sleeve away from the inlet port to open it to the canister.

The check valve assembly is in the check valve housing. The check valve assembly has two flaps and a torsion spring. When there is no fuel flow through the refuel valve the torsion spring moves the two flaps to close the outlet port. When there is fuel pressure in the refuel valve canister the flaps open against spring pressure.

J. Defuel/Transfer Valve 11QM

Defuel/Transfer Valve (11QM) and Actuator (11QU)

The primary components of the defuel/transfer valve are:

the valve body
the ball valve with a 38.1 mm (1.5 in.) bore
the valve spindle
the housing.

The ball valve is installed in the valve body. The valve body and the housing are attached to a mating flange. The valve spindle is installed in the housing and engages the ball valve in the mating flange. The housing has a mounting flange with four threaded studs to attach the defuel/transfer valve to the center tank inner skin.
The valve spindle has a location slot in one end to engage a lug in the drive gear of the defuel/transfer valve actuator.

K. Defuel/Transfer Valve Actuator 11QU

Defuel/Transfer Valve (11QM) and Actuator (11QU)

The actuator has a body with a mounting flange. The body holds a 28VDC electrical motor. This motor drives a gear which turns the defuel/transfer valve through 90 degrees. There is a mechanical indicator on the body which shows the position of the actuator (open or closed). The V-band clamp (82QM) attaches the actuator to the defuel/transfer valve.

L. Overwing Refuel Adapter 42QM(43QM) and Refuel Cap 44QM(45QM)

Overwing Refuel Adaptor and Cap ** ON A/C NOT FOR ALL

The primary components of the overwing refuel adaptor are:

the adaptor
the adaptor nut
the locking plate and lanyard.

The overwing refuel adaptor and its refuel cap are installed in the wing upper skin. The adaptor nut (with the locking plate) holds the adaptor in position. Two O-ring seals seal the joint between the adaptor and the wing upper skin. The lanyard attaches the refuel cap to the locking plate.

M. Refuel Diffuser

Refuel Diffuser

The diffuser has:

a casing assembly
a diffuser pipe
a connector.

The diffuser pipe is installed in the casing assembly. Three bolts attach the connector and the diffuser pipe to one end of the casing assembly. The connector is attached to the refuel gallery.
When fuel enters the diffuser pipe from the connector it is passed out through many small holes in the diffuser pipe. The fuel travels along the bottom of the casing assembly and out into the fuel tank. The diffuser makes sure that the fuel enters the fuel tank smoothly.

N. Air Inlet Valve

Air Inlet Valve and Fuel Drain Valve ** ON A/C NOT FOR ALL

The air inlet valve has:

a valve body
a ball valve
a banjo
a banjo bolt.

The ball valve is in the valve body and is free to move within it. The banjo bolt attaches the banjo to the valve body. The air inlet pipe connects the banjo to the outboard side of RIB21. The air inlet valve lets air into the refuel gallery so that the gallery can drain. Fuel pressure in the refuel gallery will cause the valve to close to prevent uncontrolled flow of fuel into the fuel tank.

161QM(162QM)

Air Inlet Valve 161QM(162QM) and Fuel Drain Valve ** ON A/C NOT FOR ALL

The primary components of the air inlet valve are:

the body
the end-housing
the poppet-valve and spring
the float assembly.

The body and the end-housing connect together to make a valve chamber. An O-ring seals the joint between the body and the end-housing. The poppet-valve and the spring are in the valve chamber. The float assembly attaches to the end-face of the body (with a hinge-pin). The float assembly closes the valve when the fuel level in the tank is at a given level.
If there is no fuel pressure in the chamber, the spring holds the poppet-valve open and lets air into the chamber, and thus into the refuel gallery. When a fuel pressure more than 0.2 bar (2.9 psi) is felt in the chamber, the poppet-valve closes against the spring. When the pressure decreases to less than 0.14 bar (2.0 psi) the spring opens the poppet-valve.

O. Fuel Drain Valve 31QM(32QM)

Air Inlet Valve 161QM(162QM) and Fuel Drain Valve ** ON A/C NOT FOR ALL

Air Inlet Valve and Fuel Drain Valve ** ON A/C NOT FOR ALL

The primary components of the fuel drain valve are:

the body
the end-housing
the poppet-valve and spring
the flap-valve and a torsion-spring.

The body and the end-housing connect together to make a valve chamber. An O-ring seals the joint between the body and the end-housing. The poppet-valve and the spring are in the valve chamber. The flap-valve attaches to the end-face of the body (with a hinge-pin) and is kept closed with the torsion-spring.
If there is no fuel pressure in the chamber, the spring holds the poppet-valve open. When a fuel pressure more than 0.2 bar (2.9 psi) is felt in the chamber, the poppet-valve closes against the spring. When the pressure decreases to less than 0.14 bar (2.0 psi) the spring opens the poppet-valve. This lets the remaining fuel pressure open the flap-valve and decrease to zero. When the pressure is zero, the torsion-spring closes the flap-valve to prevent a fuel flow in the opposite direction.

P. Pressure Relief Valve 97QM

Pressure Relief Valve 97QM

The primary components of the pressure relief valve are:

the mounting flange assembly
the valve pad assembly
the spider
the spring
the spring retainer
the bolt.

The mounting flange assembly is on the RH RIB1 of the center tank. The mounting flange assembly has a hole to let the fuel pass through it. The valve pad assembly seals this hole. Spring pressure holds the valve pad assembly against the mounting flange assembly. The spring is between the spider and the spring retainer. The bolt keeps all these items on the valve pad.
Fuel pressure in the center tank greater than the spring pressure on the valve pad assembly will open the valve. The fuel then moves from the center tank to the RH wing tank. When the fuel pressure in the center tank is less than the spring pressure on the valve pad assembly, the valve will close.

** ON A/C NOT FOR ALL

7. Operation/Control and Indicating

Refuel/defuel Control Panel ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel ** ON A/C NOT FOR ALL

Refuel/defuel Control Panel ** ON A/C NOT FOR ALL

Refuel/Defuel Control Panel ** ON A/C NOT FOR ALL

A. Pressure Refueling
When you use manual pressure refuel, the total quantity of fuel put into the aircraft (and the supply to each tank) is controlled at the refuel/defuel control panel (800VU).

When you use automatic pressure refuel, the total quantity of fuel put into the aircraft is controlled at the preselector (5QT). The fuel supply to each tank is monitored at the indicator (6QT).
When you use manual pressure refuel, the total quantity of fuel put into the aircraft (and the supply to each tank) is controlled at the refuel/defuel control panel (800VU and 801VU).

When you use automatic pressure refuel, the total quantity of fuel put into the aircraft is controlled at the preselector (5QT). The fuel supply to each tank is monitored at the indicator (6QT).

When you set an automatic pressure refueling, fuel quantity preselector 5QT (at the refuel/defuel control panel) controls the total quantity of fuel that goes into the aircraft. Indicator 6QT shows the quantity of fuel that is in each tank.
When you use manual control of the pressure refueling, the quantity of fuel that goes into the wing and center tanks is controlled at refuel/defuel panel 800VU. REFUEL VALVES toggle switches 4QU, 5QU and 6QU let you control the operation of individual tank refuel-valves.
If the ACT(s) is(are) installed you can control the quantity of fuel that goes into each ACT at panel 801VU. The REFUEL VALVE toggle switch(es) let(s) you control refuel valve in each ACT. If an ACT is not installed the related controls on panel 801VU do not operate.

B. Pressure Refueling
The maximum refuel pressure at the refuel/defuel coupling is 3.45 bar (50 psi). This refuel pressure will give an all tank refuel rate of approximately 1130 l/min (299 USgal/min). At this refuel rate you can refuel the aircraft (from its usual reserves to full) in approximately 20 minutes.
The maximum refuel pressure at the refuel/defuel coupling is 3.45 bar (50 psi). This refuel pressure will give an all tank refuel rate of approximately 1050 l/min (277 USgal/min). At this refuel rate you can refuel the aircraft (from its usual reserves to full) in approximately 20 minutes.
The maximum refueling pressure at the refuel/defuel coupling is 3.45 bar (50.0 psi). This refueling pressure will give an all tank refuel rate of approximately 1050 l/min (277 USgal/min). At this refueling rate you can refuel the aircraft from empty to full capacity (main fuel tanks and all ACTs) in approximately 32 minutes.
With a refueling pressure of 2.8 bar (40.6 psi) the refuel time from empty to full capacity is about 36 minutes.
When two ACTs are installed, the aircraft refuel time increases to approximately 25 minutes.
The necessary total quantity of fuel is set when you move the rocker switch, on the preselector, to INC (increase) or DEC (decrease). The quantity of fuel that is set is shown in the PRESELECTED display. The total contents actually in the tanks is shown in the ACTUAL display.

When the conditions that follow are met the tanks will start to fill:

the PRESELECTED display is greater than the ACTUAL display
the REFUEL VALVES switches set to NORM
the MODE SELECT switch set to REFUEL.

The total quantity of fuel is set when you move the rocker switch on the preselector to INC (increase) or DEC (decrease). The PRESELECTED display shows the fuel quantity set with the rocker switch. The ACTUAL display shows the total fuel quantity in the tanks. Indicator 6QT shows individual fuel quantities in main fuel tanks and ACT(s).

The tanks will start to fill when:

The PRESELECTED display is greater than the ACTUAL display
The REFUEL VALVES switches set to NORM
The MODE SELECT switch set to REFUEL.

Where the preselected quantity is greater than the maximum capacity of both the wing tanks fuel will automatically be added to the center tank.
When the preselected fuel quantity is more than the maximum capacity of the two wing tanks, fuel automatically goes to the center tank at the same time.

When the preselected quantity is more than the maximum capacity of the wing and center tanks, fuel automatically goes to the ACT(s) at the same time.
ACTs have automatic refueling sequence that follows: ACT AFT1, ACT AFT2 and ACT FWD.
When the preselected fuel quantity is more than the maximum capacity of the two wing tanks, fuel automatically goes to the center tank at the same time.
When the preselected quantity is more than the maximum capacity of the wing and center tanks, fuel automatically goes to the ACT(s) at the same time.
ACTs have automatic refueling sequence that follows: ACT AFT1 and ACT AFT2.
Where the preselected quantity is greater than the capacity of both the wing tanks fuel will automatically be added to the center tank.

Fuel will also be added to the ACT/s (when installed) if the preselected quantity is greater than the capacity of both wing tanks and the center tank.
The END annunciator, on the preselector 5QT, will come on when the refuel procedure is complete. That is when the ACTUAL value is the same as the PRESELECTED value +/- 100 kg (220 lb). If the refuel procedure stops before the ACTUAL value and the PRESELECTED value are the same, the END annunciator will flash to show a fault.
To control pressure refuel manually, the MODE SELECT switch on panel (800VU) is set to REFUEL and the REFUEL VALVES switch(es) are set to OPEN. The quantities of fuel that go into the tanks are then monitored at the indicator (6QT). When the tank(s) have the required amounts, the REFUEL VALVE switch(es) are set to SHUT.
To control a pressure refueling manually, the MODE SELECT switch on panel 800VU is set to REFUEL and the REFUEL VALVE(S) switch(es) on panels 800VU and 801VU are set to OPEN. You can monitor the quantity of fuel that goes into each tank at indicator 6QT:

LEFT, RIGHT and CTR displays show fuel quantity in the main fuel tanks.
TOTAL ACT display shows fuel quantity in all installed ACTs added together.
ACT display shows fuel quantity in the ACT selected with rotary switch selector 68QT on panel 801VU.

When the indicator shows correct fuel quantity in the tank or its HI LVL indicator comes on the related REFUEL VALVE(s) switch is set to SHUT.
To protect the aircraft, when the ACT/s is/are installed, it is not possible to refuel the ACT/s if:

the ACT transfer valve is not closed
the ACT vent valve is not open
the ACT air shut-off valve is not closed.

To control pressure refuel manually:

the MODE SELECT switch on panel (800VU) is set to REFUEL
the REFUEL VALVE switch/es on panel (800VU) is/are set to OPEN (for the wing and center tanks)
the REFUEL VALVE switch/es on panel (801VU) is/are set to OPEN (for the ACT/s).

The quantities of fuel that go into the tanks are then monitored at the indicator (6QT). When the tank/s have the required amounts, the REFUEL VALVE switch/es are set to SHUT.

C. Automatic-Refuel Abort Conditions
The system will abort the automatic refuel if one of the conditions that follow occurs continuously for 4 +0/-1 seconds:

All high level sensors are wet and the ACTUAL display shows 100 kg (220 lb) less than the PRESELECTED display.
The pre-selector that controls the automatic refuel transmits a fault signal.
A wing tank contains less than 5800 kg (12800 lb) of fuel and the center tank contains more than 250 kg (600 lb) of fuel.
The center tank contains less than 6100 kg (13400 lb) of fuel and an ACT contains more than 250 kg (600 lb) of fuel.
ACT1 contains less than 2100 kg (4600 lb) of fuel and ACT2 contains more than 250 kg (600 lb) of fuel.
The difference between the wing tank fuel quantities should be minimum of 200 kg (400 lb) and their high level sensors are dry.
The ACTUAL display shows 100 kg (220 lb) more than the PRESELECTED display.
The increase and decrease discrete inputs from the pre-selector that controls the automatic refuel are active at the same time.
The fuel volume in a wing tank is 100 l (26 USgal) more than the maximum volume.
The fuel volume in the center tank is 105 l (28 USgal) more than the maximum volume.
The fuel volume in an ACT is 50 l (13 USgal) more than the maximum volume.

The system will abort the automatic refuel if the Fuel Quantity Indicating Computer (FQIC) is at grade 3 or higher.
The system will abort the automatic refuel if one of the conditions that follow occurs continuously for 4 +0/-1 seconds:

All high level sensors are wet and the ACTUAL display shows 100 kg (220 lb) less than the PRESELECTED display.
The preselector that controls the automatic refuel sends a transmission fault signal.
A wing tanks contains less than 5800 kg (12787 lb) of fuel and the center tank contains more than 250 kg (551 lb) of fuel.
The difference between the wing tank fuel quantities should be minimum of 200 kg (400 lb) and their high level sensors are dry.
The center tank contains less than 5800 kg (12787 lb) of fuel and any ACT contains more than 250 kg (551 lb) of fuel.
ACT AFT1 contains less than 2200 kg (4850 lb) of fuel and ACT AFT2 or ACT FWD contains more than 250 kg (551 lb) of fuel.
ACT AFT2 contains less than 2200 kg (4850 lb) of fuel and ACT FWD contains more than 250 kg (551 lb)
The ACTUAL display shows 100 kg (220 lb) more than the PRESELECTED display.
The increase and decrease discrete inputs from the preselector that controls the automatic refuel are active at the same time.
Any ACT Fuel Quantity Indication (FQI) goes out of view because of FQI failure which causes gauging error greater than 5%.
The channel grade of the Auxiliary Fuel Management Computer (AFMC) is set to Failed.
Any high level sensor in the wing tanks or center tank failed
On panel 28VU, ACT XFR MODE SEL pushbutton switch is set to manual mode (the MAN legend is on).
AFMC detected an ACT configuration error.
There are no Aeronautical Radio Incorporated (ARINC) transmissions from the Fuel Quantity Indicating Computer (FQIC) master channel.

The FQIC transmits an abort status on ARINC Label 250 unless all of the conditions that follow are true:

Both wing-tank high-level sensors are wet.
The center-tank high-level sensor is wet.
Status bit '18' on ARINC label 276 is set to '1'.

The system will abort the automatic refuel if one of the conditions that follow occurs continuously for 4 +0/-1 seconds:

All high level sensors are wet and the ACTUAL display shows 100 kg (220 lb) less than the PRESELECTED display.
The preselector that controls the automatic refuel sends a transmission fault signal.
A wing tanks contains less than 5800 kg (12787 lb) of fuel and the center tank contains more than 250 kg (551 lb) of fuel.
The difference between the wing tank fuel quantities should be minimum of 200 kg (441 lb) and their high level sensors are dry.
The center tank contains less than 5800 kg (12787 lb) of fuel and any ACT contains more than 250 kg (551 lb) of fuel.
ACT AFT1 contains less than 2200 kg (4850 lb) of fuel and ACT AFT2 contains more than 250 kg (551 lb) of fuel.
ACT AFT2 contains less than 2200 kg (4850 lb).
The ACTUAL display shows 100 kg (220 lb) more than the PRESELECTED display.
The increase and decrease discrete inputs from the preselector that controls the automatic refuel are active at the same time.
Any ACT Fuel Quantity Indication (FQI) goes out of view because of FQI failure which causes gauging error greater than 5%.
The channel grade of the Auxiliary Fuel Management Computer (AFMC) is set to failed.
Any high level sensor in the wing tanks or center tank failed.
On panel 28VU, ACT XFR MODE SEL pushbutton switch is set to manual mode (the MAN legend is on).
AFMC detected an ACT configuration error.
There are no Aeronautical Radio Incorporated (ARINC) transmissions from the Fuel Quantity Indicating Computer (FQIC) master channel.

The FQIC transmits an abort status on ARINC Label 250 unless all of the conditions that follow are true:

Both wing-tank high-level sensors are wet.
The center-tank high-level sensor is wet.
Status bit '18' on ARINC label 276 is set to '1'.

D. Defueling
To defuel the aircraft you must use the main fuel pumps (Ref. AMM D/O 28-21-00-00) to remove the fuel from the fuel tanks. If there is fuel in the center (transfer) tank, you must move the fuel to the wing tanks (Ref. AMM D/O 28-26-00-00) before you can defuel the aircraft completely.
To defuel the aircraft you must use the main fuel pumps (Ref. AMM D/O 28-21-00-00) to remove the fuel from the fuel tanks.
To defuel the aircraft you must use the main fuel pumps (Ref. AMM D/O 28-21-00-00) to remove the fuel from the main fuel tanks.
To defuel the ACT(s), you must move the fuel to the center tank (Ref. AMM D/O 28-28-00-00).
If there is the fuel in the center (transfer) tank, you must move the fuel to the wing tanks (Ref. AMM D/O 28-26-00-00) before you can defuel the aircraft completely.

E. Defueling
To defuel the aircraft you must use the main fuel pumps (Ref. AMM D/O 28-21-00-00) to move the fuel from the fuel tanks to the refuel/defuel coupling.

If there is unusable fuel in the center (transfer) tank, you must move the fuel to the wing tanks (Ref. AMM D/O 28-26-00-00) before you can defuel the aircraft completely.

If the ACT/s is/are installed, and contain fuel, you must move the fuel to the center tank (Ref. AMM D/O 28-28-00-00).

To defuel the aircraft you must use the controls at the cockpit fuel panel 40VU and the refuel/defuel panel 800VU.
Set the controls at the refuel/defuel panel 800VU as follows:

set the REFUEL VALVES switches to SHUT
set the MODE SELECT switch to DEFUEL/XFR.

Set the controls at the cockpit fuel panel 40VU as follows:

push (in) (OPEN) the X FEED P/BSW (Ref. AMM D/O 28-23-00-00)
push (in) the L TK (R TK) PUMPS 1 and 2 P/BSWs (Ref. AMM D/O 28-21-00-00)
push (in) the CTR TK L XFR (R XFR) P/BSWs (Ref. AMM D/O 28-26-00-00).

F. Pressure Defuel
To defuel the aircraft you must set:

the X FEED P/BSW (Ref. AMM D/O 28-23-00-00), on the panel 40VU, to OPEN
the L TK (R TK) PUMPS 1 and 2 P/BSWs (Ref. AMM D/O 28-21-00-00), on the panel 40VU, to ON
the CTR TK L (R) XFR P/BSWs, on the panel 40VU, to ON
the REFUEL VALVES switches, on the panel 800VU, to SHUT
the MODE SEL switch, on the panel 800VU, to DEFUEL XFR.

To defuel the aircraft you must set:

the X FEED P/BSW (Ref. AMM D/O 28-23-00-00), on the panel 40VU, to OPEN
the L TK (R TK) PUMPS 1 and 2 P/BSWs (Ref. AMM D/O 28-21-00-00), on the panel 40VU, to ON
the CTR TK PUMPS 1 and 2 P/BSWs, on the panel 40VU, to ON
the REFUEL VALVES switches, on the panel 800VU, to SHUT
the MODE SEL switch, on the panel 800VU, to DEFUEL XFR.

To defuel the main fuel tanks you must:

On panel 40VU, push the X FEED P/BSW (ON and OPEN legends come on) (Ref. AMM D/O 28-23-00-00)
On panel 40VU, push the L TK PUMPS 1 and 2 (R TK PUMPS 1 and 2) P/BSWs (the ON legend comes on) (Ref. AMM D/O 28-21-00-00)
On panel 40VU, push the CTR TK L XFR (CTR TK R XFR) P/BSWs (the ON legend comes on)
On panel 800VU, set the REFUEL VALVES toggle-switches to the SHUT position
On panel 800VU, set the MODE SEL toggle-switch to the DEFUEL XFR position.

To defuel each ACT (when enough space is available in the center tank) you must use the controls at ACT fuel control-panel 28VU as follows:

Push the AUTO MODE SEL P/BSW (the MAN legend comes on the P/BSW and ACT transfer pump starts operation (Ref. AMM D/O 28-28-00-00))
Set rotary selector switch 36QH to the related ACT (inlet valve of the selected ACT opens).

G. Fuel Transfer

To move fuel from one wing tank to the other wing tank, or, to the center (transfer) tank, you must set:

the main fuel pump (Ref. AMM D/O 28-21-00-00) to ON, for the tank from which you move the fuel
the X FEED P/BSW (Ref. AMM D/O 28-23-00-00) (on the panel 40VU) to OPEN
the applicable REFUEL VALVE switch (on the panel 800VU) to OPEN, for the tank that is to get the fuel
the MODE SEL switch (on the panel 800VU) to DEFUEL XFR.

To move fuel from one tank to another tank, you must set:

the main fuel pump (Ref. AMM D/O 28-21-00-00) to ON, for the tank from which you move the fuel
the X FEED P/BSW (Ref. AMM D/O 28-23-00-00), on the panel 40VU, to OPEN
the REFUEL VALVE switch, on the panel 800VU, to OPEN, for the tank to which you move the fuel
the MODE SEL switch, on the panel 800VU, to DEFUEL XFR.

To move fuel from one wing tank to the other wing tank, or to the center tank, you must set the controls as follows:

push (in) (OPEN) the X FEED P/BSW (Ref. AMM D/O 28-23-00-00), on the cockpit fuel panel 40VU
push (in) the L TK (R TK) PUMPS 1 and 2 P/BSWs (Ref. AMM D/O 28-21-00-00) on the cockpit fuel panel 40VU, for the tank from which you move the fuel
set the REFUEL VALVE switch, on the refuel/defuel panel 800VU to OPEN, for the tank to which you move the fuel
set the MODE SEL switch, on the refuel/defuel panel 800VU, to DEFUEL XFR.

To move fuel from the ACT/s (if installed) to the center tank you must push (in) (FWD) the ACT P/BSW on the cockpit fuel panel 40VU.

NOTE: To move fuel from the ACT/s to the center tank on the ground the FUELING BUS (501PP) must be powered (access panel door 192MB must be open).
This causes the center tank high level sensor to be powered. When the center tank high level sensor is wet (or not powered) it is not possible to defuel the ACT. This prevents fuel overflowing from the center tank onto the ground.

H. ACT Refuel
When the ACT/s are installed and refuel is selected, the refuel transfer system commands these valves to the open position:

ACT refuel valve (41QU)
ACT1 fuel inlet valve (166QM1)
ACT2 fuel inlet valve (166QM2).

The ACT1, the ACT2 and the wing and center tanks are refueled at the same time. When the ACT/s is/are full the ACT high level sensors close the ACT fuel inlet valve (166QM1) and the ACT refuel valve (41QU). When these valves close, the ACT refuel stops.
To move fuel from an ACT to the center tank you must set the controls at ACT fuel control panel 28VU as follows:

Push the ACT XFR MODE SEL P/BSW (MAN legend comes on)
Set rotary selector switch 36QH to the applicable ACT.

The ACT transfer pump will stop if the center-tank high-level sensor becomes wet and continue when it becomes dry. Turn the selector switch to the next ACT with fuel when the ACT is empty.

** ON A/C NOT FOR ALL

8. BITE Test
Not applicable

[Rev.10 from 2021] 2026.04.02 07:01:16 UTC