Testing operation of speech communication

Preliminary requirements

Required Conditions

Action/Condition	Procedure/Data
Connect headsets to the pilot and copilot headset jacks.
Install the ground power unit (preferred).	Installing the ground power unit (GPU)
Set the BATT switch to the BATT position on the miscellaneous control panel (alternative).

Support equipment

Name	Identification/References	Quantity	Remark
Headset	H10-13H	2	David Clark H10-13H (or equivalent)

Safety conditions

Use a ground power unit, if available, to prevent draining the battery of its stored electrical power.

Procedure

1. Make sure that the circuit breaker (3141CB1) is closed.

2. On the Primary Flight Display (PFD) or the Multi-Function Display (MFD), tune the VHF COM transceiver to a local station frequency and adjust the volume knob to approximately 50%.

3. On the audio panel, push the COM1, MIC 1, PILOT, and COPLT pushbuttons.

4. Make sure that only the COM1, MIC 1, PILOT, and COPLT annunciators show on the audio panel.

5. Pull the trigger on the pilot cyclic to the down position (COM transmit) and do a radio check with the local station to make sure these results occur:

   • The side tone is heard clearly.

   • The transmit indicator (TX symbol) shows in the COM box of the PFD and the MFD.

   • The MIC 1 annunciator flashes at a rate of approximately one cycle per second on the audio panel.

   • The received signal from the local station is heard clearly in the pilot and copilot headsets.

   • The receive indicator (RX symbol) shows in the COM box of the PFD and the MFD when you receive the signal from the local station.

Requirements after job completion

Required Conditions

Action/Condition	Procedure/Data
Remove the ground power unit (if used).	Removing the ground power unit (GPU)
Set the BATT switch to the OFF position on the miscellaneous control panel (if used).
Disconnect the headsets from the pilot and copilot headset jacks.