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AMM 34-55-00, DME
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AMM 34-57-00, ADF
19. Operation_________
A. General
(1)
The VOR/ILS navigation system operation consists of an operational and a functional description. The operational description is a brief overall description of the system block diagram. The functional description is a more in depth description of the system components and functional schematics.
(2)
To operate the VOR/ILS navigation system, energize load control centers P6 and P18 and close the ADI, IRS, DAA, instrument transformers, VOR/LOC and glide slope circuit breakers. Also, position the VHF NAV and COMPASS transfer switches on the pilots' overhead panel to NORMAL, the HSI transfer swithes on the lightshield panel to VOR/ILS, select VOR for the RDDMI bearing pointers and select the MAN mode of operation on the VHF NAV control panels. Manually tune the systems to the local VOR station and check that the station audio output is available through the audio integrating system.
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
B. Operational Description
(1)
A block diagram of the VOR/ILS navigation systems is shown in Fig. 3. RF signals from the VOR/LOC, localizer and glide slope antennas are fed to the navigation units. The localizer antenna is selected through the ILS relays by mode logic in the DFCS flight computers. The logic requires that an ILS frequency be tuned; DFCS approach mode must be selected; and the VOR/ILS test inhibit relays in the flight instrument accessory unit energized. Heading generated in the IRS is also sent from the DAA units to the RDDMI's and then to the navigation units. The captain's RDDMI provides magnetic heading to navigation unit No. 1 while navigation unit No. 2 receives magnetic heading from the first officer's RDDMI. Using these signal inputs, the navigation unit processes the signals used by the navigation system. With the VHF NAV transfer switch in NORMAL position, signal outputs of navigation unit No. 1 control the warning flags and GS and course deviation displays in the captain's ADI and HSI, and the narrow pointer in both RDDMI's. Signals from navigation unit NO. 1 also go to the ground proximity warning and instrument warning systems; to the DFCS flight computers; and to the IRS digital/analog adapter unit No. 1 for interface with the FMCS, Navigation unit No. 2 and the first officer's ADI, HSI, and RDDMI operate in a similar manner. When the VHF NAV transfer switch is in BOTH ON 2 position, the captain's and the first officer's ADI, HSI, and RDDMI receive their inputs from navigation unit No. 2. When the VHF NAV transfer switch is in BOTH ON 1 position, all instruments indicate navigation unit No. 1 outputs.
(2)
Taking one system as an example: rotation of the remote course knob selects the desired VOR/LOC course and positions the HSI course arrow. At the time the course arrow is positioned, the selected course is also displayed on the DFCS mode select panel course counter. The course select resolver is also positioned in accordance with the selected course. Two signals from the resolver are fed to the VOR portion of the navigation unit for generation of the VOR deviation and to/from outputs. These outputs are fed to the HSI to drive the course deviation bar and the to/from display.
(3)
Position of the course deviation bar with respect to the miniature airplane, shows real airplane position with respect to the selected course. The course deviation scale dots are referenced points for showing airplane lateral displacement from the selected course. TO-FROM indication is shown by a pointer which appears from behind the course deviation scale near the center of the HSI. As the airplane passes over the selected VOR ground station, the to/from annunciation reverses 180 degrees.
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本文链接地址：737-300 400 500 AMM 飞机维护手册 导航 NAVIGATION 2(123)
