Northern Airborne Technology AA83-001 rev.4.00 - Manual (Page 40)

AA83-001 InterMUSIC™ Stereo Intercom System Manual SM09-2A Rev. 4.00
Below is a simple chart to aid in understanding audio switching in the NORMAL
Operation mode.
The following terms are used:
'Active' - Function being used.
'Muted' - Functions that are overridden by the active condition.
'Idle' - Functions that are not active, but still available for use.
↓ Affect on other functions ↓
Active feature → Music ICS RX Pilot TX Copilot TX
Music → Active Idle Idle Idle Idle
ICS → Muted Active Idle Idle Idle
RX → Muted Idle Active Idle Idle
Pilot TX → Muted Muted Idle Active Muted
Copilot TX → Muted Muted Idle Idle Active
3.3.8 Automatic Fail-safe
In the event of a power failure, automatic fail-safe operation will be activated. It can also
be enabled by pulling the AA83-001 circuit breaker. Fail-safe mode routes the pilot’s
phones, mic audio, and mic PTT directly to the COM radio.
During transmit mode, the pilot mic is directly connected to the transceiver mic. Mic
bias is provided by the transceiver, not the AA83-001. The pilot TX keyline is directly
connected to the transceiver. The sidetone audio is directly connected from the audio
source to the pilot phones.
During receive mode, receive audio is directly connected from the audio source to the
pilot phones.
In both modes, copilot and passengers have no ICS, music, sidetone, or receive
functions.
Note: In Automatic Fail-Safe mode, the receive/sidetone levels may require adjustment
at the audio source.
The pilot should confirm that all aspects of Automatic Fail-Safe operation are
working before accepting the aircraft into service.
End of section 3
Page 3-6 Feb 8, 2006
ENG-FORM: 806-0106.DOT
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