Loss of Communications — Aircraft Equipment

If radio communications appear to have failed, first check the aircraft radio equipment and settings before assuming there is a complete communications failure.

Initial Checks

PTT — Push To Talk

Check that:

• the PTT button has fully released after the last transmission;
• the PTT switch is not stuck or jammed.

Radio Power Supply

Check that:

• master switch — ON;
• avionics master — ON, if fitted;
• circuit breakers have not tripped;
• fuses have not blown; and
• the aircraft electrical system appears to be operating normally.

Radio Settings

Check that:

• the correct frequency is selected;
• the frequency is selected as ACTIVE, not standby;
• the volume is turned up;
• the squelch is correctly adjusted;
• the correct radio is selected if more than one radio is fitted; and
• the correct selection has been made on the audio panel/intercom.

Microphone and Headset

Check that:

• microphone and headset plugs are fully inserted into the correct sockets;
• headset volume is turned up;
• headset batteries are serviceable, if applicable; and
• another headset or microphone is tried if one is available.

If Communications Are Still Poor

Consider whether the problem may be caused by radio propagation rather than equipment failure.