ELT Battery Self Test
100139-00
The ELT is capable of performing a self test to verify that major ELT systems are functioning properly.
Applicable Aircraft Serial Numbers
All
Type of Maintenance
Line
Level of Certification
Owner/Pilot
Task Specific Training Required
No
Special Tools Required
None
Parts Required
None
Aircraft System and Number
10—Instruments (and Avionics)
Safety Equipment
As Needed
Consumables
None
During the self test, the ELT transmits on 121.5 MHz for 1 second, (3 audio sweeps) then transmits a 406 MHz test burst for 550ms, then returns to the armed mode.
There are two modes in which a self test can be initiated:
1. When the ELT is in the “Armed” position, pressing the “Reset/Test” switch on the cockpit remote control (RCPI) initiates a self test.
2. When the main switch of the ELT is moved from the “Off” position to the “Armed” position, it does a self test. This mode is primarily designed to provide a method to bench test the ELT, with the remote control disconnected.
Task Instructions
1. Connect an aircraft headset to the headset jacks so that radio transmissions can be heard.
2. Turn on the aircraft master switch (the ELT receives no power from the aircraft).
3. Tune the aircraft radio to 121.5 MHz, and turn the squelch all the way off to listen for the modulated carrier.
4. With the ELT main switch in the “Armed” position, and not operating, press the “Reset/Test” button on the cockpit remote control (RCPI) once. You will hear one second of 121.5 audio on the radio, followed by either one beep from the audio alert indicator, or one beep followed by a two second delay, and a second beep if all systems are functioning properly. The light will also flash on the remote.
The flashes are random and have no meaning.
5. System OK codes: One Beep or One Beep followed by a second beep two seconds later.
6. A series of 2-5 fast beeps, a 2 second delay, and the beep series repeating again indicates there is a self test function that has returned a trouble condition.
Note:
The ELT will not be disabled, but it should be inspected by a qualified avionics facility as soon as possible.
7. The trouble code returns a series of beeps with a two second delay, and then the trouble code is repeated one more time. The first beeps alert you that there is a trouble condition. The two second delay is to allow you to be ready to count the second set of beeps.Trouble code sequence: 2-5 beeps—two second delay—2-5 beeps. Trouble Codes:
◦ 2 Beeps—Battery Low
◦ 3 Beeps—Low RF Power
◦ 4 Beeps—Frequency not locked
◦ 5 Beeps—High VSWR or high current
If the self test indicates a problem, have the system inspected by a qualified avionics facility as soon as possible.
Verification Method
The task is complete when a series of beeps is heard indicating a system OK or a trouble code.
Parent topic
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