Audio Control System - BOMBARDIER LEARJET 40 Pilot's Manual

Pilot's Manual

AUDIO CONTROL SYSTEM

The pilot's and copilot's digital audio control panels are located out-
board of the PFDs on each side of the flight deck. Microphone transmit
selector buttons are located in a row along the top edge of this panel
(Figure 5-16). For night flying operations, the microphone selector but-
tons are annunciated with a lighted bar on the switch indicating the se-
lected microphone. When these latching buttons are pushed, they
connect the microphone (hand-held microphone, boom microphone, or
oxygen mask microphone) to the selected radio. They simultaneously
enable the audio associated with that radio, regardless of the setting on
the audio on/off buttons located below these microphone transmit se-
lector buttons. The microphones selector buttons are mechanically in-
terlocked so that each new selection automatically deselects the
previous selection. Depressing the PA button connects the on-side mi-
crophone to the passenger address amplifier. The audio level for the PA
is automatically adjusted for conditions and cannot be adjusted by the
crew. The pilot will use either a hand-held microphone or boom micro-
phone for transmissions. Oxygen mask microphones are used when the
MIC/MASK selector is in the extended (unlatched) position.
An EMER switch is located in the upper right corner of each audio con-
trol panel. When the EMER switch is depressed, the microphone and
audio reception is connected directly to VHF 1 and NAV 1 and all func-
tions of the audio control panel are bypassed except the headphone vol-
ume. In order to receive NAV 1 audio with EMER selected, the NAV
AUDIO switch on the clearance delivery radio must be selected ON.
When EMER is selected on the audio control panel and power is avail-
able to the control units, COM and NAV frequencies are set using either
RMU or the clearance delivery radio. If EMER is selected and electrical
power is still available to the audio panel, system warning audios will
still be available through the cockpit speaker and audio will be routed
to the cockpit voice recorder. Regardless of whether power is lost to the
audio control panel, the EMER switch is operational, however, system
warning audio and audio to the cockpit voice recorder are inoperative.
The audio source selector controls are located on the lower rows of the
audio control panel. When these push-on/push-off switches are
latched (in position) audio is turned off from that receiver. When un-
latched (out position), the audio associated with that button is connect-
ed to the headphone and also to the speaker, if it is selected on. The
audio level can be adjusted by rotating the button, counterclockwise to
decrease, and clockwise to increase the volume.
5-60
PM-132A