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INTERPILOTAIR-TO-AIRCOMMUNICATION (AIPGEN3.4)
In accordancewith regional agreements, 123.45MHZ is designated as the
air-to-air VHF communications channel. Useof this channel will enable aircraft
engaged in flights over remote and oceanic areas out of range of VHFground
stations to exchange necessary operational information and to facilitate the
resolutionof operational problems.
AERODROME FREQUENCYRESPONSEUNIT (AFRU)
(AIPGEN3.4)
To assist pilots’ awareness of inadvertent selection of an incorrect VHF
frequencywhenoperating into non-towered aerodromes, a device known as
anAerodrome FrequencyResponseUnit (AFRU)may be installed. AnAFRU
will provide an automatic responsewhenpilots transmit on theCTAF for the
aerodrome atwhich it is installed.
The features of theAFRU are as follows:
• When the aerodrome traffic frequency has not been used for the past five
minutes, the next transmissions over two (2) seconds longwill cause a
voice identification to be transmitted in response, eg, ‘GOULBURNCTAF’.
• When the aerodrome traffic frequency has beenusedwithin theprevious
five (5)minutes, a 300millisecond tonewill be generated after each
transmission over two (2) seconds long.
A series of three (3)microphone clickswithin a period of five (5) seconds
will also cause theAFRU to transmit a voice identification for the particular
aerodrome.
In theevent that the transmitter in theAFRUbecomes jammed for a periodof
greater than oneminute, the unitwill automatically shut down.
Theoperation of theAFRU provides additional safety enhancements by
confirming the operation of the aircraft’s transmitter and receiver, the volume
setting, and that the pilot has selected the correct frequency for use at that
aerodrome.
3 – commun i cat i ons
communications –ClassG
communicat ions