12.14. Instrument Landing System (ils) в737.
Подробно рассматривается в [4] рекомендуемой литературы.
Purpose
The multi-mode receiver (MMR) contains the instrument landing system and the global positioning system functions. This section only covers the instrument landing system function.
The instrument landing system (ILS) provides lateral and vertical position data neccessary to put the airplane on the runway for approach. The system uses signals from a glideslope ground station and a localizer ground station.
The glideslope ground station transmits signals to give the airplane a descent path to the touchdown point on the runway.
The localizer ground station transmits signals to give the
airplane lateral guidance to the runway centerline.
Abbreviations and Acronyms
AC - alternating current
ACP - audio control panel
alt - alternate
altn - alternate
app - approach
ARINC - Aeronautical Radio, Inc.
BITE - built-in test equipment
BL - buttock line
CAPT - captain
DC - direct current
DEU - display electronics unit
DME - distance measurement equipment
EFIS - electronic flight instrument system
F/O - first officer
FCC - flight control computer
FDAU - flight data acquisition unit
FMC - flight management computer
freq - frequency
fwd - forward
grd - ground
ILS - instrument landing system
LCD - liquid crystal display
LED - light emitting diode
LRU - line replaceable unit
maint - maintenance
MHz - megahertz
MMR - multi-mode receiver
MKR - marker beacon
NAV - navigation
NCD - no computed data
ND - navigation display
norm - normal
PFD - primary flight display
General
The instrument landing system (ILS) has two multi-mode
receivers (MMRs) that contain the ILS function. The ILS
function in the MMRs receive inputs from these antennas:
VOR/LOC antenna
Localizer antenna
Glideslope antenna.
Description
The receivers get manual tune inputs from the navigation (NAV) control panels.
The VOR/LOC antenna and the localizer antenna send localizer signals through the localizer antenna switches to the MMRs. The localizer antenna switches select the VOR/LOC antenna or the localizer antenna as the source of RF input to the MMR. The glideslope antenna sends glideslope signals to the multi mode receivers.
The multi-mode receivers send ILS deviation data to these LRUs:
DEUs
REU
GPWC
FCC
FDAU
FMC
Standby attitude indicator.
COMPONENT LOCATION
Electronic Equipment Compartment
The multi-mode receivers (MMRs) are in the electronic equipment compartment. MMR 1 is on the E1-2 shelf. MMR 2 is on the E1-4 shelf. The LOC antenna switches are on the side of the E1 rack.
Nose Radome
The glideslope and localizer antennas are in the nose radome.
The glideslope antenna is above the weather radar antenna.
The
localizer antenna is below the weather radar antenna.
POWER INTERFACES
Power Inputs
The P18-1 circuit breaker panel contains the MMR 1 and NAV CONT PNL 1 circuit breakers. The circuit breakers receive 115v ac from the 115v ac standby bus section 1. The circuit breakers supply power to the multi mode receiver 1 and the captain’s NAV control panel.
The P18-1 circuit breaker panel also contains the NAV SENSOR DC 1 and NAV SENSOR DC 2 circuit breakers. The circuit breakers receive 28v dc from the 28v dc standby bus and the 28v dc bus. The circuit breakers send 28v dc to the NAV control panels and to the integrated flight system accessory unit (IFSAU). For the ILS, The IFSAU contains circuits that supply a discrete signal to the LOC antenna switches for operation. The IFSAU uses the 28v dc from the NAV control panel and a discrete signal from the FCC to set the logic to send a discrete signal to operate the LOC antenna switches.
The P6-1 circuit breaker panel contains the NAV CONT PNL 2 and the MMR 2 circuit breakers. The circuit breakers receive 115v ac from the 115v ac transfer bus section 2. The circuit breakers supply power to the first officer’s NAV control panel and the multi mode receiver 2.
When you tune an ILS frequency on the NAV control panels, 28v dc goes to the on-side FCC and LOC antenna switch. The FCC’s use the 28v dc for mode selection. The LOC antenna switches use the 28v dc for operation.
ILS - DIGITAL INTERFACE