44 Maintenance
Airman 8
IMPORTANT:
The Airman 8 headset was designed, tested, and approved to FAA TSO C139a. The TSO
requires the headset meet the minimum performance specifications as defined in RTCA DO-
214a. This document and specifications listed here reference the test procedures and
equipment used as defined in these standards. Refer to the standard for details on how to
perform individual tests.
IMPORTANT:
Minimum attenuation requirements are not requirements of FAA TSO. To achieve the
minimum attenuation, Bosch approved test system setup is required.
ANR Test Procedure
3.1.6.0.1 Measuring ANR Circuit Voltages and Switch Function
To
measure voltage and switch function on boom-side
, do the following:
1. Verify the
headset main cable plugs are powered on
.
2. Using a voltmeter, place the
ground probe at J10
.
3. Place the
positive probe on TP 14
.
If measurement is +3.3Vdc, power regulator is good.If measurement is
anything other than 3.3Vdc +/-10 power regulator is bad. Replace the board.
To
measure the switch functionality on boom side
, do the following:
1. If regulator is good, verify the
ANR switch is in OFF position
.
2. Place the
positive probe at J11
.
If measure is near 0, switch is open.
3. Move the switch to
On position
.
If measure is at 3.3Vdc +/- 10%, the switch is good. If measure at any other
measurement, the switch is bad. Replace the board.
To
measure the fail-safe control logic for ANR
, do following:
1. Verify the
ANR switch is in the On position
.
2. Place the voltage meter
probe at J12 on boom-side
.
If measurement is greater than -6Vdc the fail-safe logic is working properly.
If the measurement is anything below -6Vdc, fail-safe logic is not working,
replace the board.
To
measure the switch and overhead cord functionality on non-boom side
,
do the following:
1. If boom-side is good, place the
positive probe at J11
.
If measure is near 0, switch is open.
2. Move switch to
On position
.
If measure is at 3.3V +/- 10%, the switch is good. If measure at any other
measurement, the switch is bad. Replace the board.
To
measure the fail-safe control logic for ANR
, do following:
1. Verify the
ANR switch is in the On position
.
2. Place the voltage meter
probe at J12 on boom-side
.
If measurement is greater than -6Vdc the fail-safe logic is working properly.
If the measurement is anything below -6Vdc, fail-safe logic is not working,
replace the board.
IMPORTANT:
If a board needs replacement due to ANR adjustment, contact Bosch ASA or Bosch certified
facility for replacement and adjustment.
Summary of Contents for Airman 8
Page 33: ...Airman 8 Parts List and Disassembly Assembly 33 5 Firmly press the headband pad into place...
Page 34: ...34 Parts List and Disassembly Assembly Airman 8...
Page 36: ...36 Maintenance Airman 8...
Page 38: ...38 Maintenance Airman 8...
Page 41: ...Airman 8 Maintenance 41 3 1 5 Speaker Troubleshooting and Workflow...
Page 43: ...Airman 8 Maintenance 43 3 1 6 ANR Troubleshooting and Workflow...
Page 48: ...48 Maintenance Airman 8...
