(3)
Ground track information is displayed by the drift angle bug read against the azimuth card relative to true north (000.).
(4)
Drift angle is displayed by the angle between the drift angle bug and the lubber line.
(5)
Crosstrack deviation is displayed by the course deviation bar relative to the course deviation scale.
(6)
Desired track information is displayed by the course arrow read against the azimuth card.
D. Two separate digital readouts are provided in each HSI, one in each of the upper corners of the instrument bezel. The left-hand readout normally displays distance to the next waypoint indicated in the TO display of the CDU. The right-hand digital readout displays ground speed information from INS No. 1. The digital displays are controlled through the CDU.
E. The HSI provides annunciators to indicate operating status.
(1)
A meter-operated VOR-ILS flag appears in the upper left area of indicator when a radio or magnetic system is being used as the source of navigation information. In the INS mode of operation the VOR-ILS flag retracts to reveal an INS legend.
(2)
A data source annunciator is located below the VOR-ILS/INS annunciator. The data source annunciator displays the numbers 1, 2, or 3 which correspond to the system in use.
(3)
A heading information annunciator is located behind the lubber line at the top of the indicator. A meter-operated MAG flag appears when magnetic heading is displayed. In the INS mode the MAG flag retracts to reveal a TRUE legend which signifies a true heading-oriented display.
(4)
An ALERT annunciator is located in the lower left portion of the instrument face. When the INS signifies that the airplane is within 2 minutes of its selected waypoint or destination, the ALERT annunciator illuminates.
F. The HSI furnishes warning flags to annunciate heading and navigation failures.
(1)
A HEADING flag drops into view behind the lubber line and obscures part of the azimuth card in event of loss of the heading valid signal from the input data source, loss of heading servo power, or excessive heading servo error signal.
(2)
A meter-driven navigation failure warning flag is located adjacent to the course deviation bar. The flag appears when navigation data is invalid.
G. The HSI biases the markers (bugs) out of the way when the information is invalid.
(1)
The preset heading bug is biased to the "6 o'clock" position when the HSI is displaying INS data.
(2)
The drift angle bug is biased out of view upon loss of INS navigation flag voltage.
9. Attitude Director Indicator (Fig. 12)
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EFFECTIVITY
AIRPLANES WITH DELCO INS CONFIG 1 02 A Page 37 Apr 25/8734-41-00
A. Two attitude director indicators (ADI) are installed in the airplane, one on each pilot's instrument panel. The indicators are used primarily to display airplane attitude. Each is, however, a composite instrument which accepts and displays glide slope and localizer deviation, radio altitude, speed deviation, decision height, flight director commands, and rate of turn signals from other navigation systems.
B. On ATLAS ALL EXCEPT AT 701-750, the captain's ADI receives pitch and roll attitude information from INS No. 1 or 3 as selected from the ATT/COMP STAB switch on the captain's flight instrument panel. Similarly, the first officer's ADI receives attitude information from INS No. 2 or 3. An illuminated annunciator adjacent to the switch shows which two of the three INS systems are supplying information to the ADI's (Fig. 1). On AT 701-750, the captain's ADI receives pitch and roll attitude information from INS No. 1 or 3 as selected from the ATTITUDE switch on the captain's flight instrument panel. Similarly, the first officer's ADI receives attitude information from INS No. 2 or 3.
C. Airplane attitude is indicated by a dc torque motor-driven sphere, representing the horizon and moving relative to a fixed airplane symbol near the center of the instrument face (Fig. 12). The sphere rotates in pitch and roll to correspond to the airplane attitude. In the event of power loss to the indicator, loss of the attitude valid signal to the indicator or detection of failures by the indicator monitor circuits, the instrument attitude (ATT) warning flag appears to indicate an invalid attitude indication.
D. Each ADI contains self-test provisions. When the test button on the front of the indicator is depressed, the sphere will indicate a change in attitude indication of approximately 20 degrees right bank and 10 degrees climb. The attitude warning flag will also appear.
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本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航2(94)
