12.1 Pf), the card output will be open circuited. The LED will be in the off condition. When the BIT switch is held in the applicable CH1 or CH2 position, the output will not change states. The LED will remain off.
(3)
A CH1 and CH2 FAIL SAFE TEST switch. The three position (center off) toggle switch on the SPS control card permits a check of the SPS fail safe circuit.
(a)
The control card is considered failed when one or more of these conditions exists: 1) An internal SPS control card problem which would change the
output signal 2) Loss of external 28 VDC power 3) Loss of a sensor CH1 or CH2 signal.
(b)
To test the fail safe circuit for a wet sensor (output open) you must: 1) Put the BIT switch to the CH1 or CH2 position and, 2) at the same time put the FAIL SAFE TEST switch to the
applicable CH1 or CH2 position.
NOTE: The LED light will go out.
____
(c) To test the fail safe circuit for a dry sensor (output grounded) you must: 1) Put the the FAIL SAFE TEST switch to the CH1 or CH2
position.
NOTE: The LED light will go out.
____
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TASK 28-16-08-705-001
2. Reserve Tank Transfer Single Point Sensor Control Card Operational Test_______________________________________________________________________
A. General
(1)
This task contains two operational tests:
(a)
An operational test at the MGMT M2 M3 SPS control card (fuel system card file, M7852) which uses the built in test (BIT) capability to do a check of these reserve tank transfer systems: 1) single point sensors for the reserve tank transfer 2) control card 3) wiring between the card and sensors.
(b)
A CMCS initiated ground test which makes sure the SPS system operates correctly for these systems: 1) reserve tank fuel transfer SPS system 2) fuel jettison SPS system
B.
References
(1)
AMM 24-22-00/201, Manual Control
(2)
AMM 28-22-16/401, Fuel System Card File
(3)
AMM 28-41-00/501, Fuel Quantity Indicating System (FQIS)
(4)
AMM 31-61-00/501, Integrated Display System (IDS)
(5)
AMM 32-09-02/201, Air/Ground Relays
(6)
AMM 34-61-02/401, Control Display Unit
(7)
AMM 45-10-00/501, Central Maintenance Computer System (CMC)
(8)
SSM 28-44-01
(9)
WDM 26-44-11, 28-44-12
C.
Access
(1)
Location Zones 115 Area Between Nose Gear Well and Fuselage, Left 221 Control Cabin, Left 222 Control Cabin, Right 521 Leading Edge to Front Spar, Left 621 Leading Edge to Front Spar, Right
D.
Preconditions
S 865-046
(1)
These conditions are necessary for this task:
(a)
Reserve Tank SPS System serviceable.
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747-400 MAINTENANCE MANUAL
(b)
A specific fuel quantity is not necessary for this task.
(c)
Electrical Power On (AMM 24-22-00/201).
(d)
Fuel System Card File serviceable (AMM 28-22-16/401).
(e)
Fuel Quantity Indicating System (FQIS) serviceable (AMM 28-41-00/501).
(f)
Integrated Display System (IDS) serviceable (AMM 31-61-00/501).
(g)
Airplane must be in the ground mode (AMM 32-09-02/201).
(h)
CDU installed (AMM 34-61-02/401).
(i)
Central Maintenance Computer (CMC) serviceable (AMM 45-10-00/501).
E.
Prepare for the Test
S 865-002
(1)
Supply electrical power (AMM 24-22-00/201).
S 865-005 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 燃油 FUEL 2(6)
