Nominal tune time of the pa-coupler is
approximately 5 seconds; therefore, the RF
TEST lamp indications below are only valid
for approximately 5 seconds after initial
5. If the RF TEST lamp stays illuminated
continuously, the receiver-exciter is
faulty. If the RF TEST lamp blinks on
and off, the pa-coupler is faulty.
6. Tune Cycle Complete. If the RF
TEST lamp is not illuminated, the tune
tone drops, and a beeping tone is
heard at the end of the time, the pa-
coupler and coupler mount failed to
tune the antenna.
7. If RF TEST lamp is not illuminated,
switch to the USB mode and supply
audio input while holding the system
keyed. If sidetone is not audible,
check audio interphone or microphone
system before replacing the eceiver-
exciter. Presence of a sidetone
indicates that the system is working
Transmitter (ELT) is provided to assist in locating an
aircraft and crew in the event an emergency landing is
necessitated. The output frequency is 121.5 and
243 MHz simultaneously. Range is approximately
line-of-sight. The aircraft may be equipped with one of
three different ELTs: the TR70-13, the TR70-17, or
the ELT-10. All three have a RESET switch and ON /
OFF / ARM switch located on the transmitter. The
TR70-13 and ELT-10 are equipped with a switch,
accessible through an access opening in the right side
of the aft fuselage. In the event the impact switch has
been inadvertently actuated, the beacon can be reset
by actuating the remote mounted switch to the RE
ARM (aft) position (TR70-13) or by firmly pressing the
RESET switch on the front of the case. Access to the
ELT is through the door on the bottom of the aft right
b. Controls and Functions.
(a) ON / OFF / ARM Switch. Controls
operation of the set.
1 ON. Turns set on for test
2 OFF. Turns set off.
3 ARM . Arms set so that it will turn
on automatically in an impact.
The TR70-17 has no remote switch.
(2) TR70-13, Remote Switch.
(a) RE ARM / ARM / XMIT Switch.
Resets, arms, or activates transmitter.
1 RE ARM. Resets transmitter if it
has been activated.
2 ARM. Arms transmitter to activate
automatically on impact. Switch on front of transmitter
must be set to ARM.
3 XMIT. Activates transmitter for test
purposes. Switch on front of transmitter may be set to
OFF or ARM.
(3) ELT-10, Remote Switch.
(a) ARM / XMIT Switch. Arms or
1 ARM. Arms transmitter when
switch on front of transmitter is set to ARM.
2 XMIT. Activates transmitter for test
Section III. NAVIGATION
The overall navigation equipment group provides
the pilot and copilot with the instrumentation required
to establish and maintain an accurate flight course and
position and to make an approach on instruments
under Instrument Meteorological Conditions (IMC).
The navigation configuration includes equipment for
determining attitude, position, destination range and
bearing, heading reference and groundspeed.