7 abnormal operation, Stuck microphone, Com tuning failure – Garmin G1000 Piper PA32 User Manual
Page 133: Audio panel fail-safe operation, Reversionary mode, 7 abnormal operation -39

190-00692-00 Rev. B
Garmin G1000 Pilot’s Guide for Piper PA32
4-39
AUDIO PANEL AND CNS
4.7 ABNORMAL OPERATION
Abnormal operation of the G1000 includes equipment failures of the G1000 components and failure of
associated equipment, including switches and external devices.
STUCK MICROPHONE
If the push-to-talk (PTT) Key becomes stuck, the COM transmitter stops transmitting after 35 seconds of
continuous operation. An alert appears on the PFD to advise the pilot of a stuck microphone.
The COM1 MIC or COM2 MIC Key Annunciator on the Audio Panel flashes as long as the PTT Key remains
stuck.
Figure 4-47 Stuck Microphone Alert
COM TUNING FAILURE
In case of a COM system tuning failure, the emergency frequency (121.500 MHz) is automatically tuned in
the radio in which the tuning failure occurred. Depending on the failure mode, a red X may appear on the
frequency display.
Figure 4-48 COM Tuning Failure
Emergency Channel
Loaded Automatically
AUDIO PANEL FAIL-SAFE OPERATION
If there is a failure of the Audio Panel, a fail-safe circuit connects the pilot’s headset and microphone directly
to the COM1 transceiver. Audio will not be available on the speaker.
REVERSIONARY MODE
The red DISPLAY BACKUP Button selects Reversionary Mode for both displays. Reversionary Mode
operation displays flight and engine information on both the PFD and MFD, in case of display failure.
See the System Overview Section for more information on the DISPLAY BACKUP Button.
Figure 4-49 Reversionary Mode Button