777 AMM 飞机维护手册 指示和记录系统 2(6)

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

Selected Altitude Highlight Box
An altitude alert box is around the selected altitude when the airplane gets to the altitude capture point. This box stays when the airplane is less than 900 feet but more than 200 feet from the selected altitude (altitude approach).
Current Altitude Box
The box around the current altitude is usually white. The box is thicker when the airplane gets to the altitude capture point. The box stays thicker when the airplane is less than 900 feet but more than 200 feet from the selected altitude (altitude approach).
The box is yellow when the airplane goes more than 200 feet but less than 900 feet from the selected altitude (altitude alert).
MCP
The altitude selector is on the MCP. The selected altitude shows in the altitude window above the altitude selector.
Rotate the altitude selector to change the selected altitude.
Caution Aural
The WEUs make a caution aural when an altitude alert occurs.
EICAS Message and Master Caution Lights
The WEUs send a digital signal to the AIMS cabinets when an altitude alert occurs. The AIMS shows an ALTITUDE ALERT EICAS caution message. The AIMS also makes the master caution lights come on.
EFFECTIVITY BEJ ALL  31-51-00 
Page 98.2 
D633W101-BEJ  Jan 05/2003 

 

WES -ALTITUDE ALERT PFD INDICATIONS AND CONTROL

EFFECTIVITY BEJ ALL  31-51-00 
Page 98.3 
D633W101-BEJ  Jan 05/2003 

WES -ALTITUDE ALERT OPERATION

Altitude Comparator
The altitude comparator compares the selected altitude with the barometric altitude. The altitude comparator supplies these outputs:
*
More than or equal to 200 feet from the selected altitude

*
Less than or equal to 900 feet from the selected altitude

*
Less than or equal to 200 feet from the selected altitude.

Alert/Approach Logic
The alert/approach logic calculates when the airplane approaches the selected altitude, or when it moves away from the selected altitude.
The alert/approach logic makes an altitude approach signal when the airplane is 200 feet or more, and 900 feet or less from the selected altitude. The altitude approach signal goes to the AIMS cabinets. The AIMS shows altitude approach indications on the primary flight displays (PFDs).
The alert/approach logic makes an altitude alert signal when the airplane goes 200 feet or more from the selected altitude. The altitude alert signals go to the aural alert logic and the AIMS cabinets.
The aural alert logic makes the caution aural.
The AIMS cabinets must receive an altitude alert signal from at least two WEU channels. The AIMS does these functions:
*
Shows the ALTITUDE ALERT caution message

*
Shows the altitude alert indications on the PFDs

*
Makes the master caution lights come on.

Altitude Alert Inhibit
When the altitude alert inhibit signal is true, the altitude alert/ approach logic does not make an alert. The WEUs use these signals in the altitude alert/approach inhibit logic:
*
Glideslope (G/S) mode engaged

*
All gear down and locked

*
Flaps in landing position.

Operational Check of the Altitude Alert Function
When the parking brake is set, the altitude alert inhibit signal is false. This permits an operational check of the altitude alert function on the ground.
Move the altitude selector on the mode control panel (MCP). You will see altitude approach indications when the difference between the selected altitude and the barometric altitude is 900 feet or less. After that, you will see altitude alert indications when the difference between selected altitude and barometric altitude is 200 feet or more.
EFFECTIVITY BEJ ALL  31-51-00 
Page 98.4 
D633W101-BEJ  Jan 05/2003 

 

777 AIRCRAFT MAINTENANCE MANUAL

WES -ALTITUDE ALERT OPERATION

EFFECTIVITY BEJ ALL  31-51-00 
Page 98.5 
D633W101-BEJ  Jan 05/2003 

WES -STALL WARNING FUNCTION

General
The stall warning function has these four functions:
*
Stick shaker activation

*
Pitch limit indication (PLI) calculation

*
Speed tape parameter calculation

*
Auto slat enable.

Stick Shaker Activation
The WEUs make the stick shaker actuators come on when the airplane has a corrected angle of attack (AOA) (alpha) that is too high.
The stick shaker trip point (AOA STRIP) logic calculates the AOA STRIP. The logic uses these inputs:
*
Mach number from the air data inertial reference unit (ADIRU). Channels L1 and R1 use the ADIRU as the primary source and the SAARU as the secondary source. Channels L2 and R2 use the SAARU as the primary source and the ADIRU as the secondary source
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：777 AMM 飞机维护手册 指示和记录系统 2(6)