Northern Airborne Technology AMS42 - Manual (Page 67)

SM19 Rev. 4.00 AMS42/44 Dual Channel Audio Controller Manual
Nov 21, 2003 Page 3-13
ENG-FORM: 806-0102.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
3.12.1.1 Emergency Mode Effects
In the EMER mode, all functions are retained by the pilot and copilot, 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.
Note that in the EMER mode, all switches work exactly as they do during NORM operation,
except for the RX and ICS volume controls which will have no effect.
Any selected receive audio is switched to the appropriate user in the ‘emergency’ mode (red
mode switch in the EMER position), but not to any passengers in the system. Level will be
lower than NORM operation because the signals are obtained directly from the radios,
bypassing the electronics in the controller. This is provided for failure situations which make
operation impossible in the NORM mode (i.e., loss of power or amplifier failure, etc.)
3.12.2 Isolation Operation
The mode switch can select an ISO function, which prevents the selected user from
receiving ICS audio. This is useful when passengers are interfering with critical flight
operations (landing, etc.). It can be preselected at installation to isolate the left or right
side. Intercom operation for the passengers and copilot is not affected. It is normally set for
isolation of the right side when the unit is shipped from the factory.
End of Section 3 .0