Northern Airborne Technology AMS43, Installation And Operation Manual

Page: 40 / 42

AMS43 Single Channel Audio Controller Manual SM59 Rev. 4.00
Page 3-4 Nov 10, 2003
ENG-FORM: 806-0106.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
The mode switch (red switch bat) is used to select between NORMAL and PILOT
ISO/EMR modes. In the NORMAL position (down), all operations of the ICS are
functional as described above. When the switch is in the PILOT ISO/EMR position, the
pilot is isolated from the rest of the passengers. If the controller is operated in the
ISO/EMR mode, ICS operation will continue (if there is no fault condition) between the
passengers and copilot, but will exclude the pilot. See section 3.4 for further details.
3.4 Emergency Operation
When the red PILOT ISO/EMR - NORMAL 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 RX audio is switched to the primary user (pilot) in the
ISO/EMR 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 Audio Alerting Functions
Two types of audio alerting are supported in the AMS43: Direct Audio and Internal
Alerting. The use of these alerting features should be determined, defined and
recorded so that the operator has an opportunity to use these features as they were
intended for their specific installation.
3.5.1 Direct Audio
Direct Audio is when an audio signal from an existing warning system is connected
‘directly’ into the audio system, and is not front panel selectable. There are two Direct
Audio inputs on the AMS43. Direct Audio 1 is amplified/adjustable and Direct Audio 2 is
connected directly to the pilot's headset output.