T-45A UJPT, E2-C2, ADV, & IUT Eng-21
CNI System
normal or alternate circuits. The path
to which the audio signals are sent
depends on the position of the ALT-
NORM switch
(1) NORM: selects normal audio
amplifiers in each cockpit
(2) ALT: selects alternate audio
amplifier for use when normal
amplifier fails. Amplifies all inputs
at fixed audio level
(a) Failure of either comm
amplifier can result in the loss
of receiver audio signals.
Setting the ALT-NORM switch
on the applicable COMM
control panel to ALT
deenergizes the NORM-FAIL
relay. The contacts of the
NORM-FAIL relay change
over to send the alternate
circuit output to the headsets
and isolate the headsets from
the failed normal circuit output
(b) The various receiver audio
signals selected are a
combination of those selected
on the system control panel
and no volume control is
available. The alternate
circuit only provides a fixed
level of audio signal
amplification
(c) Each pilot can select ALT ICS
should his normal amplifier
circuits fail. This selection is
independent of the other
cockpit setting. When ALT
ICS is selected, that cockpit
will automatically go to hot
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