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FREQUENCY DISPLAY
SELECT KNOBSTEST SWITCH
VHF Navigation Control Panel
Figure 8
EFFECTIVITY AIRPLANES WITH LTN-72RL OR
CONFIG 3 LTN-92 INS
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(1)
OFF - Power is applied to the MSU and CDU edge lighting and CDU data keyboard. System primary power is off.
(2)
On airplanes with LTN-92 INS:
(a) STBY/ALIGN - System automatically levels itself and determines the direction of true north. When alignment is complete, the CDU NAV line displays 2, and the TIME line displays 0.0 MIN indicating that NAV mode may be selected. The airplane must not be moved during alignment; however, fuel, cargo and passengers may be loaded. The control display unit is fully operable to allow display test and insertion of date (for the navigation database unit), airplane present position, and GMT.
NOTE: The system must be allowed to enter NAV mode or turned
____ off before the airplane can be moved.
On airplanes with LTN-72RL INS: STBY - Control display unit is fully operable to allow display test and insertion of airplane present position. The gimbal assembly cages to the airplane axes, and platform temperature stabilization and gyro runup are initiated. The system is not affected by airplane movement. ALIGN - System automatically levels itself and determines the wander angle. When alignment is complete, the READY NAV light comes on indicating the NAV mode may be entered. The airplane must not be moved during alignment; however, fuel, cargo and passengers may be loaded.
NOTE: If the mode switch is moved from ALIGN to STBY position,
____ it must be recycled back through the OFF position and the system realigned. The alignment cannot be maintained while the airplane is moved by just changing mode switch from ALIGN to STBY, moving the airplane and then returning mode switch to ALIGN position. The system must be allowed to enter NAV mode or turned off and returned to STBY mode before the airplane can be moved.
(3)
NAV - This is the normal inflight operating mode of the system and must be selected prior to moving the airplane. The computer receives acceleration information from the platform and computes airplane position and guidance information.
(4)
ATT REF - Provides pitch and roll attitude signals and a platform heading output only. No navigation capability is available and the CDU displays status data only. ATT REF must be manually selected by the operator.
(5)
On airplanes with LTN-92 INS, the ALIGN annunciator comes on during system alignment to indicate that the alignment sequence is in progress. Upon completion of a valid alignment and NAV position is selected, the ALIGN annunciator goes out. The annunciator has press-to-test capability.
EFFECTIVITY
AIRPLANES WITH LTN-72RL OR CONFIG LTN-92 INS 01 Page 22 Apr 25/91
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HEADING
WARNING TRUE/MAG HEADING
FLAG ANNUNCIATOR
DRIFT ANGLE SCALE
COURSE ARROW
GLIDE SLOPE
DEVIATION
POINTER
AZIMUTH CARD
COURSE DEVIATION BAR
AIRCRAFT SYMBOL
Figure 9
EFFECTIVITYAIRPLANES WITH LTN-72RL OR
CONFIG 3 LTN-92 INS
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On airplanes with LTN-72RL INS, the READY NAV Annunciator comes on when system alignment has been completed and mode selector may be set to NAV position. READY NAV light goes out when NAV position is selected. The annunciator has press-to-test capability.
(6) The BATT Annunciator comes on when 28-volt dc backup battery voltage has decreased below 20 volts dc. Also the CDU WRN light comes on and the system should be turned off. The annunciator has press-to-test capability.
10. Control Display Unit (Fig. 7)
____________________
A. The control display unit (CDU) is used to enable the entry of data into the INU, to select flight plans and to display data from the INU.
B. The CDU LED alphanumeric display, single unit annunciators, and
pushbuttons function as follows:
(1)
LED diode matrix display (display) - Displays five lines and 16 characters per line of data selected by data select pushbuttons or entered by data entry pushbuttons. Top line is title heading and remaining four lines are data entered or INU output data; when appropriate, lines can be slewed upward or downward by use of slew pushbuttons.
(2) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址:747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航2(132)