AA95-766 Single Channel Audio Controller
SM95-766 Installation and Operation Manual
June 20, 2012 Rev: 3.00
Page 3-4
ENG-FORM: 806-0100.DOTX
CONFIDENTIAL AND PROPRIETARY TO ANODYNE ELECTRONICS MANUFACTURING CORP.
3.4 Emergency
Operation
When the red mode switch is set to the ISO/EMR position, the pilot is removed from the ICS bus and
connected directly to the selected radios. This mode should be selected in the event of a box fault or
power failure.
In the ISO/EMR mode, all functions are retained by the pilot, except ICS and possibly boom mic
operation. If the box or airframe fault prevents the TX annunciator from lighting during transmit (indicating
a failure in the mic keying circuit), then the hand mic should be used. A power fault of any kind will
prevent the TX annunciator from lighting, giving an immediate indication of failure. If ICS audio is still
available, then the power to the controller has not failed, and loss of the TX light indicates TX switch
failure.
In the ISO/EMR mode, all switches work exactly as they do during NORMAL operation, except for the RX
and ICS volume controls, which have no effect.
The ISO/EMR function should be tested prior to flight to ensure proper operation, and allow the radio
levels to be set adequately for emergency operation.
Any selected receive audio is switched to the primary user (pilot) in the ‘emergency’ mode, but not to any
passengers in the system. Audio level will be lower than in NORMAL operation because the signals are
obtained directly from the radios, bypassing the electronics in the controller. This is provided for failure
situations that make operation impossible in the NORMAL mode (i.e. loss of power or amplifier failure,
etc.)
3.5 Direct
Audio
Direct Audio is an audio signal from an existing warning system that is connected ‘directly’ into the audio
system, and is not front-panel selectable. The Direct Audio signal is an amplified input, and can be
adjusted at the time of installation (see section 2.3.4.2).
End of Section 3.0
