BOMBARDIER LEARJET 40 Pilot's Manual page 66

Pilot's Manual
The INPH (interphone) volume control adjusts the on-side headset au-
dio level when the interphone function is used. The interphone oper-
ates on a "hot microphone" basis. The interphone is not available over
the cockpit speaker except when the oxygen mask audio is selected.
The MIC/MASK control allows for microphone audio switching be-
tween the boom/hand-held microphone (MIC) and the oxygen mask
microphone (MASK). When the switch is latched (depressed position),
MIC is selected and when the switch is unlatched (out position), MASK
is selected.
The MASK intercom feature provides interphone audio to the on-side
cockpit speaker. Audio is available regardless of the SPKR ON/OFF
button position. Selecting INPH allows adjustable volume control of
the off-side MASK intercom on the speaker.
Warning system audio signals are input to the audio panel for dissem-
ination to the flight crew over the headphones and speaker. The audio
output from the headphone, speaker, and microphone are recorded by
the Cockpit Voice Recorder (CVR). The CVR microphone is the input
for the AGC circuit and if the CVR microphone becomes disabled, or
the CVR circuit breaker is pulled, then the aural warnings will be at the
fixed HIGH volume level. If the Crew Warning Panel (CWP) has detect-
ed a fault in any one of the audio output channels, or in the Automatic
Gain Control (AGC) input, a CAS annunciation will be posted.
The following CAS illuminations are specific to the crew warning panel
audio:
CAS
WARN AUDIO
WARN AUDIO
The pilot's audio panel receives 28-vdc from the left essential bus and
is protected by a 3-amp circuit breaker labeled AUDIO 1/CLR DLY on
the pilot's circuit breaker panel (AVIONICS [COMMUNICATIONS]
group). The copilot's audio panel receives 28-vdc from the right essen-
tial bus and is protected by a 3-amp circuit breaker labeled AUDIO 2 on
the copilot's circuit breaker panel (AVIONICS [COMMUNICATIONS]
group). The passenger address amplifier receives power from the left
essential bus and is protected by the CABIN PA 5-amp circuit breaker
on the pilot's circuit breaker panel (AVIONICS [COMMUNICATIONS]
group).
5-62
Color
Amber The audio function of the Crew Warning
Panel (CWP) has failed.
White • A Crew Warning Panel (CWP) audio output
channel fault is detected.
• A problem exists with the Automatic Gain
Control (AGC).
Description
or
PM-132A