HR Smith Techtest 503 Series, Руководство по обслуживанию

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Commercial In Confidence
Issue 17 - 11.04.18 - CN 10407
HRS1013-04-02
1. SYSTEM DESCRIPTION
The Techtest Limited 503 Series of Emergency Locator Transmitter (ELT) is a battery
powered unit that on activation, provides full emergency frequency operation at 121.5 MHz,
243.0 MHz and 406.025 MHz.
The 503 ELT can be used as a fixed or fixed/ portable system, with options of two or three axis
G-Switch units for automatic activation of the beacon should the aircrew not have activated
the beacon prior to the emergency. The system can include an interface unit, which is
designed to update the 406.025 MHz transmission with the latest onboard positional data.
The Remote Controller for the ELT system makes it possible to test and operate the ELT
from the aircrew positions and an in-built sounder and lamp indicates the system status.
An external antenna is mounted on the airframe in a position most likely to survive an
accident.
The Water Activated Switch provides the ELT with automatic activation upon immersion in
salt or fresh water.
By design the 503 ELT system is modular in construction and a number of configurations
can be assembled.
This manual covers the system module by module and then comments on the various
configurations. The reader has to select the sections of this manual that are relevant to the
particular installation on the aircraft.
The COSPAS-SARSAT message programmed is determined by the COSPAS-SARSAT
authority of the country where the ELT is to be registered. It should be noted however,
that a USER-LOCATION protocol message only encodes positional information with a
resolution of 4 minutes. The NATIONAL-LOCATION and STANDARD-LOCATION protocol
message formats encode positional information with a resolution of 4 seconds. It is strongly
recommended for systems that include positional information (GPS), a STANDARD-
LOCATION or a NATIONAL-LOCATION protocol message is chosen.
winBeacon (QA-00-120) is a software package supplied by Techtest that can be used to
Encode or Decode COSPAS-SARSAT messages. This is a stand-alone package that does
not connect to any hardware.
2. LINE REPLACEMENT UNITS (LRU’s)
2.1 ELT 503-1 (Figure 1)
The ELT is manufactured in high visibility yellow thermoplastic. It is self contained
and has its own long life battery, control switch and antenna port.
The battery (A0673-1) has an installed unused life of 5 years and will always provide,
as a minimum, 24 hours use at 406.025 MHz (5 watts) and 48 hours use at 121.5
MHz and 243.0 MHz (0.1 watts).
The 503-1 forms the basic transmitting unit which, in the portable mode, can be
operated as a stand alone unit provided that an antenna is connected.
The battery can be changed without the use of tools by simply depressing two locks,
one either side of the unit, with finger pressure and simultaneously sliding the battery
out. Replacement batteries are simply slid into position and the locks engaged.
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