Northern Airborne Technology AMS43 - Manual (Page 24)

AMS43 Single Channel Audio Controller
SM59 Installation and Operation Manual
Section 3 Rev: 1.00 Issue 4 Page 3-4
ENG-FORM: 806-0111.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
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.
3.5.2 Internal Alerting
Internal Alerting is provided by three separate, internal tone generators that are coupled to the headset
output. These tones are a function of the AMS43 itself, and can be used to supplement existing warning
tones (Low Rotor, Engine Out warnings in a Bell 206) or provide unique alerting capability for functions
such as ICS Call, Rad Alt DH warning, etc. The internal alerts, and how they will be used, are determined
at the time of installation and are not front panel selectable.
Section 3 ends