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4.0
MAINTENANCE
4.1
Testing
CAUTION: FCC regulations require that ELT testing be performed in an RF shielded
room. Testing outside of a shielded room may only be performed during the first five
minutes of each hour, and then only for a maximum duration of three audio sweeps
(equivalent to one flash of the red indicator light).
The ELT should be tested periodically for proper operation. An ELT should always be
tested prior to installation or re-installation. Periodic testing will help to assure that the
ELT will function optimally and reliably in the event of an emergency.
To properly test the ELT, a receiver capable of tuning to the international distress
frequencies (121.5 and 243 MHz) is required. The ELT does possess a self test feature
which monitors the signal at the antenna terminal. The red indicator light will flash only
if the proper signal is detected. However, no self test can be 100% complete. The only
way to completely guarantee that the unit is fully functional is to monitor the ELT signal
on an independent piece of equipment.
If the test receiver has an antenna that is not detachable, the test receiver should be
located just outside of the RF shielded room. If open air testing is attempted, the receiver
should be located at least 100 meters away from the ELT under test. If the receiver has a
detachable antenna, an alternative method is to disconnect the receiver's antenna and
locate the receiver in close proximity (less than 1 meter) to the ELT under test.
To test the ELT:
1) Set up the receiver as described in the paragraph above. Tune the receiver to 121.5
MHz.
2) Pour approximately 1/2" of water into a dish or pan and place the ELT upright into
the water so that the bottom of the unit is immersed.
3) Check to see that red indicator light is flashing approximately once per second.
4) Listen for distress signal coming from receiver.
5) Tune receiver to 243 MHz and again listen for distress signal.
6) The ELT is fully functional if and only if distress signals are heard at both 121.5 and
243 MHz and the red indicator light flashes without interruption.
If the conditions specified in step 6 are not met, send or bring the unit to an authorized
ACR service center for further testing and repair.
4.2
Visual Inspection
In addition to functional testing, the ELT should also be periodically inspected for
physical damage. Physical damage may compromise the reliability of the unit even if it
appears to be fully functional. When inspecting the unit for damage, pay particular
attention to the following:
3
Y1-03-0090-1 Rev. D
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