3
C
AUTIONS
AND
A
DVISORIES
Operational advisory
The Bose
®
Aviation Headset is an active noise reducing (ANR)
headset. As with any complex electronic device, it is possible for this
headset to fail during operation. Symptoms of failure may include
loud tones, distortion, and loss of communications signal in the
headset when used in the ANR mode.
Note:
The headset includes redundant circuitry to reduce the effects
of such failures and allow for continued use of the headset in the
ANR mode.
If you experience loud tones and the related loss of communications,
turn off the power switch. The headset will continue to provide com-
munications in the passive noise-reducing mode.
ANR mode is active when the headset control module power switch
is set to ON (Figure 1) or when the battery power indicator is lit. The
headset is in the passive mode when the power switch is set to OFF,
or when the battery power indicator is unlit.
Figure 1
On/Off switch on (a) the
battery powered headset
and (b) the aircraft powered
headset
(b)
(a)
Battery power
indicator
Power
switch
Power source
Your headset is one of two types: battery powered, or aircraft
powered.
If your headset is battery powered, make sure it is connected only to
battery power. If your headset is aircraft powered, connect the head-
set to the aircraft power sources only as described in this guide.
An aircraft powered headset will not operate properly if used with a
Bose Series II Aviation Headset battery pack or with any commercial
battery pack.