HR Smith Techtest 503-35-1 - G-Switch Variants; Remote Controller Variants

Commercial In Condence
Issue 17 - 11.04.18 - CN 10407
HRS1013-04-02
2.2 G-Switch 503-7 Series, 503-19 Series, 503-35 Series & 503-36 Series
(Figures 2 & 3)
The G-Switch forms an essential part of the xed ELT system.Dependant upon
the model in the particular system, the G-Switch triggers the ELT into transmission
when the ‘G’ force exceeds a preset limit in TWO or THREE
bidirectional axis. The G-Switch is always installed along with the ELT and is
connected via the 9 pin connector.
2.3 Remote Controller 503-4, 503-17, 503-20, 503-52 & 503-53 (Figures 4 & 5)
The Remote Controller is a small switch unit from which the aircrew can test / reset
the ELT, or switch it ON in an emergency, before the G-Switch automatically activates
the system.
The front panel has an indicator lamp and the unit has a sounder inside which gives
an audible tone.
The 503-52 Remote Controller is the same as the 503-20 but is mounted vertically
2.3.1 AF/AP ELT Cockpit Control Panel 503-51 (Figure 6)
The AF/AP Cockpit Control Panel has similar functions to the 503-20 but
with an additional Fault indicator and Inhibit switch.
2.4 Mounting Rack A0637 Series
To be effective the G-Switch has to be mounted to coincide with the expected ‘G’
forces in any accident. It is therefore necessary to mount the G-Switch to the
airframe in the correct attitude and ensure that the ELT is permanently connected to
the G-Switch.
The mounting rack will be positioned to best withstand high ‘G’ loading in the event
of an emergency and may not be readily located.
2.4.1 Fixed Mounting Tray (Figure 7)
The Fixed Mounting Tray is secured to the airframe by the four Dzus fasteners
or four xing screws.
2.4.2 Fixed / Portable Tray (Figures 8 & 9)
The Fixed / Portable Tray is secured to the airframe by six xing screws
except for Figure 9 which has nine xing screws. The ELT can, as required,
be withdrawn from the rack. In the installed position the G-Switch, which
is pre-installed into the rack, is coupled to the ELT and has an RF lead to the
antenna.
Should the ELT be required as a stand alone unit the antenna lead is
disconnected, the toggle clip is lifted and the ELT withdrawn from the rack.
A portable antenna is provided and is stowed along the top of the ELT rack,
this should be removed and tted to the ELT. The ELT can then be switched
on and used as a portable ELT unit.
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