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
63. existence [ ig'zistns ] n. 存在;现有
64. replace [ ri:' pleis ] vt. 替换;代替
65. loosen [ 'lu:sn ] v. 松开;松驰
66. captive screw [ 'kæptiv ] 自动保险螺钉
67. housing [ 'hauzi ] n. 外壳;框架;机座
68. release [ ri'lis ] vt. ; n. 释放;松开
TEXT
[1] The alternate ( or auxiliary ) navigation control display unit
( ANCDU ) in its normal function provides the interface between the
flight crew and the FMC, and contains circuitry to support this function.
The ANCDU contains a keyboard for data entry or for requesting data to
be displayed; a cathod ray tube ( CRT) that displays information; a
microprocessor that controls the operation of the CDU; a receiver that
receives information from the FMC; and circuits that control character
generation and display on the CRT. The display format is contained in
the FMC .Two ANCDU are installed in the FMCS. The CDUs are
physically and functionally identical. Both CDU can be used
independently or simultaneously for control and display during a flight.
Either CDU may be utilized to enter system data. The basic display
format consists of an array of fourteen 24-character lines. A variety of
alpha- numeric characters and symbols can be presented on each line
under the control of the FMC.
[2] The CDU alpha-numeric keyboard provides the operator with a
means of entering data into the system for initialization of the
Fig. 37-1 Alternate Navigation CDU (normal function)
LNAV/ VNAV navigation and guidance modes, and for modification of
flight plans . The alpha-numeric key group also includes the special
purpose slash (/) , change sign (+/-), decimal point (.), and clear (CLR )
keys. All entries initiated by operation of the alpha-numeric keyboard
initially appear in the scratch pad area of the display. The scratch pad
content can be edited or cleared by pressing the CLR key. When an entry
is present in the scratch pad, a brief depression of the CLR key will clear
the last character in the entry. If the CLR key is held down for more than
1 second, the entire entry in the scratch pad wil be cleared.
[3] The flight phase and function key group has 13 keys. This group
represents the capabilities of the FMCS most used during operation of
the airplane. The phases of flight that can be preplanned and controlled
by the FMCS are climb ( CLB), cruise ( CRZ) and descent ( DES). The
capability of the FMCS to manage flight is based on the utilization of the
fallowing function keys:
INIT/ REF (initialization lreference) key, DIR/INTC (direct/
intercept ) key, N1 LIMIT key, RTE ( route) key, LEGS ( route lege)
key, FIX ( fix information ) key, DEP/ARR (depature /arrivals ) key,
HOLD key, PROG (flight progress) key, and EXEC (execute ) key.
Entry of the data into the operational display is accomplished by pressing
an appropriate line select key ( LSK). Twelve LSKs are provided on the
CDU panel, six on each side of the CRT. The placement of the LSKs
aligns them with the third , fifth, seventh , ninth, eleventh , and thirteenth
lines of the display. Data entries are permitted in those lines only. Some
displays provide menus of function or mode options that can be selected
by the operator, and in these cases the LSKs are used to accomplish that
selection. In addition to transferring data from the scratch pad up to the
data display, the LSKs can be used to duplicate data from the display
lines into the scratch pad. When the scratch pad is empty, pressing the
LSK associated with the data required copies the data into the scratch
pad. The delete ( DEL) key is a special purpose key which is used to
remove data from the display after the data has been line selected and
accepted into a data field. The DEL key must be pressed once for each
parameter to be deleted.
[4] If a function has more than one page of display data associated with it,
the page number block at the upper right corner of the CRT display will
indicate this . The page number consists of two numbers separated by a
slash. The first number indicates what page is currently displayed, and
the second number indicates the total number of pages in the string.
Pressing the NEXT PAGE key advances the display to the next higher
numbered page, while pressing the PREV ( previous ) PAGE back up the
display to the next lower numbered page. The page strings are
continuous.
[5] There are 4 annunciator on the front of the CDU, only two are used
by the 737 FMCS. The 2 annunciators are MSG and FAIL. The MSG
annunciator is white in color, and is illuminated to indicate to the
operator the presence of an alert or advisory message. The FAIL
annunciator is amber in color and is illuminated if any system failure is
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空工程英语基础（中英文对照）(63)
