12-5 TESTING EMERGENCY LOCATOR TRANSMITTER. The transmitter operates on the emergency
frequencies of 121.5 and 243 MHz; both of these frequencies are monitored by the various FAA installations.
Before performing any operational test of the ELT. the following precautions should be observed:
—CAUTION—
Testing of an ELT should be conducted in a screen room or metal enclosure to
ensure that electromagnetic energy is not radiated during testing. If a shielded
enclosure is not available, testing may be performed in accordance with the
following procedures:
1. Test should be no longer than three audio sweeps.
2. If the antenna is removed, a dummy load should be substituted
during the test.
3. Test should be conducted only within the time period made up of the
first five minutes after any hour.
4. If the operational tests must be made at a time not included within the
first five minutes after the hour, the test should be coordinated with the
closest FAA Tower or Flight Service Station. Consult FAA Advisory
Circular AC 20-81 for detailed information concerning above
caution.
a. Remove the access plate on the right side of the fuselage aft of sta. 228.30.
b. Tune the aircraft communications receiver to 121.5 MHz and switch the receiver ON; deactivate the
squelch, and turn the receiver volume up until a slight background noise is heard.
—NOTE—
If the aircraft is not fitted with a communications receiver, request that the tower
listen for your test.
c. On the transmitter, set the ON/ARM/OFF switch to the ON position. Keep the switch in this position
for only a few seconds; then set to the OFF position. Return to the ARM position.
—NOTE—
The test transmission should have been picked up by the aircraft
communications receiver and/or control tower. During cold weather,
there may be a slight delay before transmission occurs.
d. A transmitter which is functioning properly should emit a characteristic downward swept tone.
e. When the test is completed, ascertain the transmitter ON/ARM/OFF switch is in the ARM position.
f. Install the access panel on the right side of the fuselage aft of sta. 228.30.
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
E L E C T R O N I C S
2G2