S 864-016
(2)
Set the transponder select switch on the ATC control panel to the 1 position.
S 744-033
(3)
Push the TEST switch on the left ATC transponder.
(a) Make sure the self-test passes and no faults are detected.
S 744-043
(4)
Release the TEST switch on the ATC transponder.
S 864-040
(5)
Set the transponder select switch on the ATC control panel to the 2 position.
S 744-036
(6)
Push the TEST switch on the right ATC transponder.
(a) Make sure the self-test passes and no faults are detected.
G. Put the Airplane Back to Its Usual Condition
S 864-029
(1) Remove electrical power if it is not necessary (Ref 24-22-00/201).
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH ATC MODE S ú
34-53-41
ú ú 01 Page 403 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
DME SYSTEM - DESCRIPTION AND OPERATION
______________________________________
1. General_______
A. The DME (distance measuring equipment) system automatically measures the distance (in nautical miles) between the airplane and a selected ground station. The system measures the airplane-to-station slant-range distance (line-of-sight) and the information is displayed on a digital readout indicator as miles-to-go. The system is designed to indicate a range of approximately 390 nautical miles.
B. Two complete DME systems are installed in the airplane. Each system consists of an interrogator (transmitter-receiver) unit, an antenna, two distance indicators and a remote tuning control panel (Fig. 1).
C. The DME system measures the distance to the navigation facility by transmitting a pulse-coded interrogation signal which actuates a corresponding ground station reply. This reply signal is received and processed by the interrogator. The output of the interrogator is applied to the digital readout of the RDDMI DME indicator (Fig. 2).
D. Manual DME frequency selection and self-test are controlled using the VHF NAV control panel.
E. The flight management computer (FMC) may select the operating frequency of DME-1 and DME-2 respectively when the proper mode is selected on the appropriate VHF NAV control panel. Also, the DME provides distance data to the FMC (Fig. 2).
F. An audio signal from the DME interrogator is applied to the flight interphone system.
G. Suppression signals between the ATC transponders and DME interrogators prevent mutual interference between the systems.
2. Control Panel_____________
A. Each ground station is assigned a specific VOR frequency and an associated DME frequency. Since the DME system operates in conjuction with the VOR/ILS navigation system, controls for both are located on the same control panel.
B. The control panel consists of the following controls and switches:
(1)
AUTO/MAN Selector Switch
(a) The AUTO/MAN selector switch is a push-on/push-off illuminated switch that is used to select either AUTO or MAN frequency control of the VHF NAV and DME systems. The selected frequency control mode is annunciated by the switch. AUTO selection is armed by the airplane NAV/VOR-ILS switching. NAV must be selected for display on the HSI before AUTO frequency control can be selected.
(2)
Frequency Selector Controls
(a) Dual concentric controls are provided for the manual selection of the frequency. The outer knob controls tens and units and the inner knob controls tenths and hundredths. The frequency range is 108.00 to 117.95 MHz, selectable in 50 KHz steps. The frequency manually selected is displayed by the manual frequency display.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITHOUT EFIS ú
34-55-00
ú ú 04 Page 1 ú Feb 25/87
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
DME System Component Location 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 导航 NAVIGATION 4(16)
