HR Smith Techtest 503 Series, Maintenance Manual

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Commercial In Confidence
Issue 17 - 11.04.18 - CN 10407
HRS1013-04-02
9
Note:- An antenna or equivalent load must be connected to the ELT when
performing tests .
The G-Switch needs to be connected to a 28V power supply and a remote controller.
System diagnosis is performed by ensuring that the locking toggle switch on the
G-Switch is in the centre OFF position, and switching it to armed whilst the
test switch is held in the test position. When a single bleep is heard, the test switch
is released. The G-Switch will then test the system, but rather than just giving six
bleeps to indicate a failure, will produce differing numbers of bleeps according to the
fault(s) as follows: -
Bleeps Fault
2 Communications failure between the G-Switch and ELT.
3 G Force sensor 0 failure.
4 G Force sensor 1 failure.
5 G Force sensor 3 failure.
7 ELT battery failure.
8 ELT RF failure
9 ELT test failure
10 Sounder failure
A single bleep indicates that the diagnostics are completed. In the event of more
than one fault there is a one-second gap between each set of bleeps. The G-Switch
will not be able to read the ELT test results if there is a communications failure.
4.5 Repair
No maintenance over and above physical inspection and battery replacement is
possible at other than at the manufacturers.
4.6 Antenna
The antenna and R.F feeder should be subject to VSWR test using a Techtest
Test Set 12-602-8 on an annual basis.
4.7 Operation
When any part of the ELT system is disturbed the built in test should be initiated
(see Operating manual) and the results recorded. Actual transmitted data can be
monitored on a Test Set 12-503-26
Note : The Test Set has its own separate manual.
5. RECHARGING & CONDITIONING THE G-SWITCH BATTERY PACK
Overview
The G-Switch is fitted with a removable re-chargeable battery pack consisting of five
Nickel Metal Hydride cells series connected, with a protection device. The function of the
battery pack is to provide power to the G-Switch in the event of the aircraft losing electrical
power. The capacity of the battery pack is high in comparison with the current drawn by
the G-Switch .