User Manual
Table Of Contents
- About your Bose® A20® Aviation Headset
- Components
- Preparing the Headset for Use11
- The battery compartment
- Connecting the headset to the aircraft
- Wearing and adjusting the headset
- Using the control module
- Primary and secondary audio sources
- AUX audio sources (wired)
- Bluetooth® audio sources (wireless)
- Using the headset with a Bluetooth® device
- Pairing the first device
- Pairing another device
- Switching between connected devices
- Bluetooth multi-function button
- Making and answering calls
- Reconnecting to a previously connected device
- Recovering a lost connection
- Disconnecting a Bluetooth device
- Clearing the headset pairing list
- Controlling Bluetooth volume
- Using the headset with a Bluetooth® device
- Secondary audio modes
- Cleaning the headset
- Instructions for continued airworthiness
- Managing multiple secondary sources
- Ordering parts and accessories
- Contact information
- Limited warranty
- Locating the headset serial number
- Mounting the aircraft panel connector
- Replacing parts
- Microphone windscreen

Troubleshooting
English - 31
Look for the problem in the left column of the table, then follow the “What to do”
instructions in the right column. If the problem persists, contact Bose using the
contact information on page 42 of this guide for assistance.
Warning: Do not attempt to disassemble or service the inside of the earcups or
other parts of the headset. Only the boom microphone cable, access
cover, batteries, windscreen, headband cushion, and ear cushions are
replaceable by the user. For instructions on how to care for and maintain
the headset, see “Headset Care and Maintenance” on page 25.
Noise reduction
Problem What to do
Communication,
but no Acoustic
Noise Cancelling
®
noise reduction
in either ear
• Make sure the headset is turned on.
• On the control module, check the power indicator. See page 18.
• If using aircraft power, check the aircraft fuse or circuit breaker.
• If using battery power, make sure the batteries are fresh and
correctly installed.
Warning: Replace batteries with alkaline batteries only. Do not use
any other battery chemistries.
No active
Acoustic Noise
Cancelling noise
reduction and no
communication
• Make sure the headphone plugs are securely inserted into the panel
connectors.
• Try using the headset in a different seat location.
• Remove the microphone assembly from the headset and check for
damage to the connector or pins. See “The microphone assembly”
on page 11.
Intercom communications
Problem What to do
Acoustic Noise
Cancelling noise
reduction, but no
incoming audio
• On the control module, make sure the volume controls are not set
too low. See “Intercom volume controls” on page 19.
• On the intercom/radio, make sure the volume controls are not set
too low.
• Make sure the headset is firmly connected to the aircraft panel.
• Try a different seat location in the aircraft.