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AILERON AND FLAPERON CONTROL -AILERON FEEL AND CENTERING MECHANISM
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AILERON AND FLAPERON CONTROL -AILERON TRIM
Purpose
The pilots use the aileron trim switches to adjust the trim of the airplane about the longitudinal axis.
Location
Dual aileron trim switches are on the aft end of the P8 aft aisle stand. The aileron trim indicator placards are on top of each control column.
Functional Description
The pilot controls the roll trim with the two aileron trim switches. The switches command the aileron trim actuator. One switch does the arm function and the other does the control function. The pilot must operate both switches at the same time to supply power to the trim actuator.
The electrical load management system (ELMS) controls the electrical power to the aileron trim switches through the aileron trim inhibit relay. The ELMS electronic unit (EEU) receives wheel backdrive actuator engagement signals from the AFDCs.
When none of the wheel backdrive actuators is engaged, ELMS keeps the aileron trim inhibit relay deenergized. Electrical power then goes to the aileron trim switches. The arm switch supplies electrical power and motor ground to the control switch which then supplies the direction of the motor rotation.
When one or both wheel backdrive actuator is engaged, the ELMS energizes the aileron trim inhibit relay which stops power to the aileron trim switches. This prevents the operation of the aileron trim during autopilot operation and bank angle protection (BAP) activation.
The aileron trim actuator moves the control wheels at a rate of
2.6 degrees per second. The roll trim authority is 30 degrees of control wheel rotation in both directions.
The aileron trim indicator placards show the amount of trim in units. Each unit indicates 5 degrees of control wheel rotation.
EFFECTIVITY BEJ ALL 27-11-00
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D633W101-BEJ Sep 05/2002
AILERON AND FLAPERON CONTROL -AILERON TRIM
EFFECTIVITY BEJ ALL 27-11-00
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D633W101-BEJ Jan 05/2002
AILERON AND FLAPERON CONTROL -WHEEL POSITION TRANSDUCERS
Purpose
The six wheel position transducers measure the position of the control wheels. The transducers send analog electrical signals to the ACEs.
Physical Description
Each wheel position transducer is an LVDT. The ACEs supply 7v ac, 1800 Hz excitation power.
The six wheel position transducers are identical to the six column position transducers, the four pedal position transducers, and the rudder trim position transducer.
Three wheel position transducers are on the right shaft assembly and three are on the left shaft assembly. The position transducers attach at one end to the lateral control support bracket assembly. They attach to the transducer crank at the other end.
Each transducer crank attaches to its shaft assembly with a spline. The spline has a missing tooth to help locate the crank on the shaft. Each transducer crank has two shear rivets to allow override of a jammed position transducer.
Each position transducer has an electrical cable which connects to the ACE connector bracket. This bracket has three receptacles, one for each position transducer. Each receptacle is identified by a placard. The order in which each position transducer connects to the receptacles of the connector bracket determines the transducer-to-ACE relationship.
Location
The six wheel position transducers are between the flight deck floor and the nose gear wheel well. Access is by the access hatch of the MEC, then along the left side of the nose gear wheel well.
Functional Description
When the right and left shaft assemblies turn in response to a control wheel input, the control wheel position transducers extend or retract. Each position transducer sends an analog electrical signal to one ACE.
Indications
The status message CONTROL WHEEL XDCR shows when one of the wheel position transducers is defective. When two or more wheel position transducers are defective, the status message FLIGHT CONTROL SYS shows.
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