4) A click should be heard within the ELT and the active light should begin to blink. Monitor ELT activation by observing the ELT LED. For a more thorough test, monitor the transmission with an AM receiver tuned to 121.5 MHz, as described in ‘Transmitter test’ section.
Operation: The ELT should remain ‘off’ until an acceleration of 4.5 ft/sec or more is applied axially, in the rearward direction. This action should activate the unit, transmitting immediately on 121.5MHz. Allow ELT to transmit only long enough to verify operation.
Caution
Do not allow test duration to exceed 5 seconds.
A false alarm may be generated.
Any time the ELT is activated it is transmitting a 121.5 MHz distress signal. If the unit operates for approximately 50 seconds, a “live” 406 MHz distress signal is transmitted and is considered valid by the satellite system. Any time that the ELT is cycled from “ARM” to “ON” and then back to “ARM”, a 406 MHz signal is transmitted, however it is specially coded as a “self-test” signal that is ignored by the COSPAS-SARSAT satellites.
Reset ELT by turning ELT switch to “ON” then to “ARM” position.
Notes:
. Be sure the correct pins are shorted. Some connections will force the ELT to activate when made. Others will keep the unit from activating in any circumstance. No combination of shorts will cause permanent damage to the ELT, however all wrong pin combinations erroneously indicate a faulty ELT.
. If the ELT activates without any pins shorted it is defective and should be returned for repair.
. As with all beacon-testing, this test should be performed within the first 5 minutes of the hour, and any local control tower is to be advised of this test.
. The RF cable can be left disconnected to reduce the level of transmitted signal. This should still allow reception within a few hundred feet (or more).
4.4.7 Reinstall ELT
Reinstall the ELT into aircraft as follows:
1) Insert the ELT into the rear of the mounting tray at an angle so the locking ears at the end fit into the mounting tray locking slots.
2) Fasten the Velcro strap around the ELT so that it is firmly held in place.
3) Visually inspect connections ensuring they are seated properly.
4.4.8 Antenna Test
AC 43.13 advises:
“A low quality AM broadcast receiver shoud be used to determine if energy is being transmitted from the antenna. When the antenna of the radio (tuning dial on any setting) is held about 6 inches from the activated ELT antenna, the ELT aural tone will be heard on the AM broadcast receiver. This is not a measured check, but it does provide confidence that the antenna is radiating sufficient power to aid search and rescue. The aircraft’s VHF receiver, tuned to 121.5 MHz, may also be used. This receiver, however, is more sensiive and could pick up a weak signal even if the radiating ELT’s antenna is disconnected. Thus it does not check the integrity of the ELT system or provide the same level of confidence as does an AM radio.”
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本文链接地址：DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL ME406P ELT(29)
