General
Emergency Locator Transmitters (ELTs) are required
for most general aviation airplanes (14 CFR 91.52). ELTs of various types have been
developed as a means of locating downed aircraft. These electronic, battery-operated
transmitters emit a distinctive downward sweep audio tone on 121.5 MHz and 243.0 MHz. If
"armed" and subjected to crash forces, they are designed to automatically
activate and continuously emit these signals. The transmitters will operate continuously
for at least 48 hours over a wide temperature range. A properly installed and maintained
ELT can expedite search and rescue operations and save lives.
Testing
ELTs should be tested in accordance with the manufacturer's instructions, preferably in a
shielded or screened room to prevent the broadcast of signals which could trigger a false
alert. When this kind of testing cannot be done, aircraft operational testing is authorized
on 121.5 MHz and 243.0 MHz as follows.
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Tests should be conducted only during the first five minutes after any hour.
If operational tests must be made outside of this timeframe, they should be coordinated
with the nearest FAA Control Tower or FSS.
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Tests should be no longer than three audible sweeps.
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If the antenna is removable, a dummy load should be substituted during test procedures.
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Airborne tests of the ELT are not authorized.
False Alarms
Use caution should to prevent the inadvertent activation of your ELT in the air or while
it is handled on the ground. Accidental or unauthorized activation will generate an
emergency signal that cannot be distinguished from the real thing, which could lead
to expensive and frustrating searches. A false ELT signal could also interfere with
genuine emergency transmissions and hinder or prevent the timely location of crash sites.
Frequent false alarms could also result in complacency and decrease the vigorous reaction
that must be attached to all ELT signals.
Numerous cases of inadvertent activation have occurred as a result of aerobatics,
hard landings, movement by ground crews, and aircraft maintenance. These false alarms can
be minimized by monitoring 121.5 MHz and/or 243.0 MHz as follows.
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Prior to engine shut down at the end of each flight.
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When the ELT is handled during installation or maintenance.
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When maintenance is being performed in the vicinity of the ELT.
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When the aircraft is moved by a ground crew.
If you hear an ELT signal, turn off the ELT to determine if it is transmitting. If it has
been activated, maintenance might be required before the unit is returned to the
"ARMED" position.
Inflight Monitoring
While you are flying, you might want to use your second radio (if installed) to monitor
121.5 MHz and/or 243.0 MHz to assist in identifying possible emergency ELT transmissions.
If you hear an ELT signal, report the following information to the nearest air traffic
facility.
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Your position at the time the signal was first heard.
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Your position at the time the signal was last heard.
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Your position at maximum signal strength.
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Your flight altitudes and frequency on which the emergency signal was heard -
121.5 MHz or 243.0 MHz.
If possible, give these positions relative to a navigation aid. If the aircraft has
homing equipment, provide the bearing to the emergency signal with each reported position.
Search and Rescue Satellite (SARSAT)
Search and rescue is a lifesaving service provided through the combined efforts of the
federal agencies signatory to the national search and rescue plan, and the agencies
responsible for search and rescue in each state. Operational resources are provided by the
US Coast Guard, Department of Defense components, the Civil Air Patrol, the Coast Guard
Auxiliary, state, county, and local law enforcement and other public safety agencies.
The introduction of the SARSAT system enhances the effectiveness of search and rescue.
SARSAT also amplifies the importance of ensuring that your ELT remains silent, except for
authorized testing or in an actual emergency. Search and rescue missions launched
because of a false ELT signal are costly and unnecessary. Search and rescue services
include search for missing aircraft, survival aid, rescue, and emergency medical help
for the occupants after an accident site is located.
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