曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
EFFECTIVITY
GUN 111-114, 201-999 73-30-00
Page 8
D633A101-GUN Jun 10/2006
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
CFM56 ENGINES (CFM56-7) 737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
73-30-00-002
Purpose
The fuel flow transmitter measures the fuel mass-flow that goes
to the manifolds and fuel nozzles. This data goes to the EEC.
The EEC sends the data to the common display system (CDS).
Location
The fuel flow transmitter is on the fan case at the 10:00 position.
To get access to the fuel flow transmitter, open the left fan cowl.
Functional Description
Fuel flows from the HMU to the fuel flow transmitter. An
aperture in the fuel flow meter moves in proportion to the massflow
of the fuel. A turbine in the flow meter turns at a constant
speed. The flow meter has two windings, one on the aperture
and the other fixed in the flow meter housing. A magnet on the
turbine passes close to these windings. Each time the magnet
passes close to a winding it makes an electrical pulse. One
pulse becomes the start pulse and the other is the stop pulse.
The time between the pulses gives the position of the aperture
and the fuel mass-flow. The EEC measures the time difference
between the start and the stop pulses and calculates the fuel
mass-flow. When the fuel mass-flow rate is low, the time
difference between the pulses is small. This shows on the DU as
a low fuel flow. When the fuel mass-flow rate increases, the time
difference between the pulses is large. The larger the difference
in time between the start and the stop pulses shows as a higher
fuel flow rate on the DU. The EEC sends fuel mass-flow data to
the DEUs.
NOTE: When the DEUs cannot find fuel flow data, or the fuel
flow data is not correct, the fuel used stays at the last
calculated value and fuel flow blanks.
ENGINE FUEL AND CONTROL - FUEL INDICATING - FUEL FLOW TRANSMITTER
EFFECTIVITY
GUN ALL 73-30-00
Page 10
D633A101-GUN Oct 10/2005
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
CFM56 ENGINES (CFM56-7) 737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
73-30-00-003
ENGINE FUEL AND CONTROL - FUEL INDICATING - FUEL FLOW TRANSMITTER
ENGINE FUEL AND CONTROL - FUEL INDICATING - FUEL FLOW TRANSMITTER
EFFECTIVITY
GUN ALL 73-30-00
Page 11
D633A101-GUN Oct 10/2005
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
CFM56 ENGINES (CFM56-7) 737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
73-30-00-003
General
The fuel filter differential pressure switch shows when a fuel
filter begins to clog (almost bypassed). The fuel filter differential
pressure switch sends a signal to the EEC. The EEC sends the
signal to the DEUs. The DEUs cause the amber FILTER BYPASS
light to come on.
Location
The fuel filter differential pressure switch is at the 8:00 position
on the fan case. To get access to the fuel differential pressure
switch, open the left fan cowl.
Functional Description
The differential pressure switch assembly has one switch to
supply data to the EEC, channnels A and B. The switch closes if
the filter clog causes a difference between filter inlet pressure
and outlet pressure of more than 11.5 psid. The EEC sends a
signal to the DEUs. The DEUs make a ground to cause the
amber FILTER BYPASS light and the MASTER CAUTION lights
to come on. If the differential pressure continues to increase,
the fuel filter bypass valve will open.
Training Information Point
If the fuel filter differential pressure switch signals disagree, the
EEC sends a signal to DEU only if the airplane is on the ground
for more than 90 seconds. If the FILTER BYPASS light comes on
after the airplane lands, go to the engine maintenance pages in
the control display unit (CDU). Look for the FUEL FILTER
SIGNALS DISAGREE message. If you do not see the message,
follow procedures in part II of the maintenance manual to
change the fuel filter. If you see the message, use the FIM for
the filter clogged indication system troubleshooting.
See the engine indicating section for more information on the
engine maintenance pages in the CDU. (SECTION 77-00)
ENGINE FUEL AND CONTROL - FUEL INDICATING - FUEL FILTER DIFFERENTIAL PRESSURE SWITCH
EFFECTIVITY
GUN ALL 73-30-00
Page 12
D633A101-GUN Oct 10/2005
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
CFM56 ENGINES (CFM56-7) 737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
73-30-00-004
ENGINE FUEL AND CONTROL - FUEL INDICATING - FUEL FILTER DIFFERENTIAL PRESSURE SWITCH
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
ENGINE FUEL AND CONTROLS(45)
